
Citation: Michela Illiano, Luigi Sapio, Ilaria Caiafa, Emilio Chiosi, Annamaria Spina, Silvio Naviglio. Forskolin sensitizes pancreatic cancer cells to gemcitabine via Stat3 and Erk1/2 inhibition[J]. AIMS Molecular Science, 2017, 4(2): 224-240. doi: 10.3934/molsci.2017.2.224
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Investigation of bacterial biofilms is a relevant topic both in fundamental and applied sciences. The general concept of biofilm production is quite well understood (bacterial surface attachment, formation of biofilm, dispersal), however regulatory processes of motile-sessile transitions still need to be elucidated. Furthermore, the rise of antibiotic resistant biofilm producing strains motivated a search for compounds that might effectively block formation of biofilms [1]. Plant polyphenolic tannic acid (TA) and its monomer gallic acid (GA) have been recently reported as potentially strong anti-biofilm agents [2]–[5]. Despite numerous researches, mechanisms of bactericidal anti-biofilm action remain obscure because existing works present data on MICs (mimimal inhibitory concentrations) and MBCs (minimal bactericidal concentrations) in planktonic cultures and mass biofilm formation values in the presence of GA and TA. But in fact, under these conditions, there is very little information on both viability of cells inside the biofilms and effects on the genes involved. In Gram-negative bacteria Escherichia coli attachment to solid surfaces involves csgBAC and csgDEFG operons (synthesis, secretion, and assembly of curli components) under certain conditions [6],[7]. Production of biofilm matrix main exopolysaccharides poly-beta-1,6-N-acetyl-D-glucosamine (PGA) and colanic acid is controlled by pgaABCD and cps operons [8],[9]. Regulation of these processes requires global stress response regulator RpoS which increases levels of signal molecule known as bis-(3′-5′)-cyclic diguanylic acid (c-di-GMP), stimulating loss of flagella, expression of curli, cellulose and PGA synthesis [10]. It has recently been shown that ci-di-GMP signaling in bacterial biofilm formation is redox-sensitive [11],[12]. Plant phenolic compounds are known as redox active substances with antioxidant and prooxidant properties [13] that may act as stimulants for normal gut microbiota growth and development contributing to improvement of state of human health [14],[15]. Fundamental mechanisms of TA and GA on biofilm formation are still poorly understood while dualism of plant phenolics action (pro- and antioxidant activities) requires a diligent research involving model microorganisms. Using laboratory strains originated from Escherichia coli BW25113 and its mutant derivatives which genetics and physiology under normal conditions are quite well understood allows observing and interpreting both possible modes of action of TA and GA. In order to check if redox properties of these compounds make any contribution to biofilm formation, we measured their real-time effects on redox parameters including dissolved oxygen (dO2), medium redox potential (Eh) and sulfide levels. Earlier, using E. coli BW25113 we have shown that 1 mg/ml TA and 4 mg/ml GA acted as MICs on M9 media with glucose, no MBC or MBPC for TA was found, but for GA these were equal to 4 mg/ml [16]. In this paper, we studied the effects of sub-MICs of TA and GA on colony-forming ability of biofilms and their counterpart planktonic cultures, mass and specific biofilm formation in wild-type E. coli BW25113 strain and mutants lacking genes involved in surface attachment (csgA, ydeH), exopolysaccharide production (pgaA, wcaM), general stress response and SOS-response (rpoS, recA) as well as estimated effects of TA and GA on changes in membrane potential (ΔΨ) and extracellular potassium (K+), expression of sulA::lacZ and katG::lacZ genes.
The strains of E. coli BW25113 (wt) and its derivatives JW1010 (ΔpgaA), deficient in production of exopolysaccharide poly-beta-1,6-N-acetyl-D-glucosamine (PGA), JW1025 (ΔcsgA), deficient in curli production, JW1528 (ΔydeH) with suppressed flagella synthesis, JW2028 (ΔwcaM), deficient in production of exopolysaccharide colanic acid, JW2669 (ΔrecA), lacking a SOS-response activator, and JW5437 (ΔrpoS), deficient in regulator of global stress response, were from Keio collection [17].
The strains carrying transcriptional gene fusions katG::lacZ were constructed by transformation of the parental strain with pKT1033 plasmid [18]. The strains with sulA(sfiA)::lacZ fusions were created by P1 transduction from the strain DM4000 [19].
Bacteria were grown overnight in M9 minimal medium supplemented with 2 g/L glucose [20]. After centrifugation, the cells were resuspended in fresh M9 medium (4 g/L of glucose) to an initial optical density at 600 nm (OD600) of 0.1. This culture was transferred to 96-well polystyrene microtitre plates (200 µL per well) containing 2 mg/mL of GA or 0.5 mg/mL of TA (sub-MICs as preliminary determined) and incubated statically at 37 °C for 22 h to obtain biofilms. These plates were used further to estimate cell viability in biofilms and their counterpart planktonic cultures as well as to measure mass and specific biofilm formation in the presence of TA and GA.
Growth conditions for real-time monitoring of medium redox potential (Eh), dissolved oxygen (dO2) and extracellular sulfide and K+ levels and for measurement of TA and GA effects on membrane potential and katG and sulA gene expression were as follows. Night cultures of the wild-type strain were grown with shaking (150 rpm) in M9 minimal glucose (0.15%) medium [20]. After centrifugation, these cells were resuspended in 100 ml of fresh medium (OD600 of 0.1) and grown aerobically at 37 °C to OD600 of 0.4. Then, TA or GA were added to a final concentration of 1.7 mg/mL and growth was monitored for 1 h. The specific growth rate (µ) was calculated by equation µ = Δln OD600/Δt, where t is the time in hours. Phenolic compounds for these experiments were prepared in 96% ethanol and then poured in the ratio 1:100 into 100 ml of the growing cultures in order to exclude effects of the solvent. No significant effects of the solvent were registered then.
Preliminary to the whole set of experiments, pH of the cultivation medium was equal to 7.0. Addition of TA and GA to the cell-free medium to reach the level of working doses both in real-time and microtiter experiments did not cause any pH shifts.
Reagents including gallic acid (catalogue number G7384-100G) and tannic acid (catalogue number 16201), agar, Luria-Bertani broth, 2-nitrophenyl-β-D-galactopyranoside (ONPG), ΔΨ-sensitive fluorescent dye DiBAC4 (3) were from Sigma-Aldrich Chemical Co (St Lous, MO, USA). Other reagents were of analytical grade (Reachim, Russia).
Colony-forming ability (CFU/mL) was estimated in planktonic cultures that had developed above the biofilms after 22 h incubation. 10 μL drops of serial dilutions were plated on LB-agar (1.5%). To estimate CFU in biofilms, medium was removed, biofilms were washed with sterile saline and sonicated by two pulses (37 kHz, 30W) for 1 min each with pause time of 1 min in a water bath sonicator (Ultrasonic cleaning unit Elmasonic S10 H, Elma, Germany). Then, OD600 was measured and 10 μL drops of serial dilutions were plated on LB-agar. Colonies were counted in 24 h after incubation at 37 °C [21].
In order to estimate effects of TA and GA on viability we used a parameter of total amount of CFU × 105/mL which was the sum of CFU × 105/mL in biofilms and their counterpart planktonic cultures. We also evaluated the percentage amount of CFU × 105/mL in biofilms in relation to the total amount of CFU × 105/mL.
Mass biofilm formation (BF) was monitored using the modified crystal violet microplate biofilm assay previously described [22],[23]. Wells of 96-well polysterene microtiter plates were prepared as described above. Control wells contained bacteria-free medium or phenolic compounds only. Broth was removed and wells were rinsed twice with 200 µL of sterile saline. The wells were air dried and 150 µL per well of 0.1% crystal violet solution was added for 30 min. Then, the colourant was discarded and the wells were rinsed five times with distilled water. The plates were air dried for 1 h. To quantify biofilms, 200 µL of 96% ethanol was pipetted into each well. After 5 min, 125 µL of the solution was transferred to a separate plate where the OD540 were measured using xMark™ Bio-Rad spectrophotometer.
The total biofilm formation (BF) or, the mass of biofilms, was calculated using the formulae:
BF = AB – CW, where AB is the OD540 of stained biofilms and CW is the OD540 of stained control wells.
To determine specific biofilm formation, values of BF were divided by the CFU values in the biofilms.
Dissolved oxygen (dO2) in E. coli BW25113 cultures were continuously measured directly in the flasks using a Clarke oxygen electrode InPro 6800 (Mettler Toledo). The dO2/pH controller of a BioFlo 110 fermentor (New Brunswick Scientific Co., USA) was used for data recording.
Redox potential (Eh) in the cell-free medium and E. coli cultures was continuously measured directly in the flasks using platinum and reference electrodes and Mettler Toledo SevenCompact™ pH/Ionmeters S220.
Changes in the levels of extracellular K+ were continuously registered directly in the flasks using the system of K+-selective (ELIS-121K) and reference electrodes and a computer pH/ion meter cpX-2 (IBI Pushchino, Russia). For K+ measurements, E. coli cells were grown as described above, except that the medium contained a low K+ concentration (0.1 mM).
Extracellular sulfide levels were detected directly in the flasks using the system of sulfide-specific ion-selective XC-S2-001 (Sensor Systems Company, Russia) and reference electrodes and a computer pH/ion meter cpX-2 (IBI Pushchino, Russia).
Changes in the membrane potential (ΔΨ) were evaluated using ΔΨ-sensitive fluorescent dye DiBAC4 (3) [24] as described previously [20]. After addition of 1.7 mg/mL phenolic compounds into 100 mL of aerobically growing cultures at OD600 = 0.4 aliquots of culture samples were collected at time 0, 30 and 60 min. Samples of log-phase cells treated with protonophore carbonylcyanide m-chlorophenylhydrazone (CCCP, 20 mM) were used as positive control. Fluorescent cells were counted using a Leica DM2000 microscope as earlier described [25]. Total cell number was counted in transmitted light. About 1000 cells were counted for every sample and all experiments were conducted 3–6 times on separate days.
β-galactosidase activity in reporter strains carrying fusions of the genes katG, and sulA with the gene lacZ using a SmartSpec Plus Spectrophotometer (Bio-Rad, USA) was measured [20].
After addition of 1.7 mg/mL polyphenols into 100 mL of aerobically growing cultures at OD600 = 0.4 aliquots of culture samples were collected at time zero and further every 15 min during 1 h. β-galactosidase activity was expressed in Miller units, calculated using the formula:
Each result is indicated as the mean value of at least five independent experiments ± the standard error of the mean (SEM). Significant difference was analyzed by Student's t-test. A P-value of 0.05 was used as the cut-off for statistical significance. Results were analyzed by means of Statistica 6 (ver. 6, 2001; StatSoft Inc.).
Without phenolic compounds, after 22 h of static incubation of the wild-type cultures total amount of CFU × 105/mL was equal to 85 ± 10 (Figure 1A) and contained 1.64% of biofilm (Figure 1B). In the presence of TA and GA, total viability decreased by 2 times. However, percentage amount of CFU in biofilms increased up to 11 and 9%, respectively. This showed both strong bactericidal effects on planktonic cultures and an increase in share of CFU in biofilms which could be seen as an adaptive response of the wild-type cells to action of the tested polyphenols.
In the absence of tested compounds, total amount of CFU × 105/mL in csgA and recA mutant strains was similar to the parental strain. In ydeH, wcaM and rpoS it was about 30% higher while in pgaA it was 19% lower compared to the parental strain (Figure 1A). Similarly to the parental strain, incubation with TA and GA led to a decrease in total CFU in all mutant strains. More remarkable effects were found in recA and pgaA where TA decreased total CFU by 6 and 5 times, respectively, while in the parental strain TA inhibited total CFU only by 2 times (Figure 1A). As for GA, inhibition level of total CFU was quite similar in parental and mutant strains.
Without phenolic compounds, percentage of CFU in biofilms in relation to total CFU increased in all tested mutants with the exception of wcaM mutant (Figure 1B). The highest share of biofilms was found in ydeH which was 2.6 times higher compared to the wild-type. 22 h incubation with polyphenols increased this parameter in all mutant strains with the exception of GA in csgA and TA in pgaA strains (Figure 1B).
Under our conditions, after 22 h incubation of wild-type bacterial cultures in M9 medium with addition of glucose in 96-microtiter polystyrene plates value of OD540 was equal to 0.108 ± 0.009. pgaA mutation decreased mass biofilm formation (BF) almost by half. While ydeH mutation resulted in 25% BF increase (Figure 1C). Presence of GA and TA resulted in BF stimulation in the wild-type by 2.8 and 2.2 times, respectively. Stimulating effects by both phenolic compounds were observed in all the mutants tested with the exception of ydeH. The highest degree of stimulation was seen in pgaA where there was a 6-time and 3-time stimulation by TA and GA, respectively, compared to pgaA mutant not treated with phenolics.
In the absence of tested compounds, SBF in the wild-type was equal to 0.080 ± 0.008. pgaA mutation led to a remarkable decrease of the parameter by 4 times. ydeH and rpoS mutations decreased SBF by about 2.7 times (Figure 1D). Incubation of the wild-type with both polyphenols had a little effect on SBF. However, in the presence of TA pgaA and recA mutants dramatically increased SBF by 10 and 3 times, respectively, compared to the wild type treated with TA. csgA mutant in the presence of GA demonstrated a slight increase in SBF.
The observed bactericidal action of TA and GA on planktonic cultures after 22 h incubation could result from plant phenolics-induced oxidative stress which stimulated the cells to switch from planktonic lifestyle to biofilms [13]. These metabolic alternations could happen on early stages of incubation of bacterial cultures. So, in a separate series of experiments we decided to observe real time effects of GA and TA on redox-parameters of the cultivation medium.
A set of experiments in cell-free M9 medium allowed us to reveal remarkable levels of redox-activity of GA and TA. Addition of GA and TA into the cell-free M9 medium resulted in gradual decrease of dO2 from 100% to 94% and 74% for TA and GA, respectively, revealing autooxidation of these polyphenols (Figure 2A). There also was a sharp and irreversible decrease of cell-free medium Eh approximately by 120 mV (Figure 2B). In cell-free model experiments, we observed a decrease of potential of sulfide-specific electrode by 2 and 18 mV in the presence of GA and TA, respectively. This might reveal presence of small amounts of S2− ions in the tested polyphenols corresponding to concentrations 8 and 35 nM, respectively (Figure 2C).
In real-time experiments the specific growth rate in the wild-type was 0.65 ± 0.02 before addition of tested compounds, while 15 min after addition, TA and GA led to an approximately 3-time decrease in the specific growth rate (data not shown). In microtiter experiments growth rate was not measured.
When TA and GA were added into aerobically growing cultures of E. coli BW25113 in mid-logarithmic phase (OD600 = 0.4) a slight inhibition of respiration during 15 min was found which then turned to a normal state (Figure 2D). This might point out a response of the cells to a stress provoked by TA and GA.
Without phenolic compounds, cultivation of aerobically growing cultures of E. coli BW25113 was accompanied by a gradual decrease of medium Eh up to negative values when oxygen was depleted. When tested compounds were added into aerobically growing cultures in mid-logarithmic phase (OD600 = 0.4), there also was a sharp irreversible decrease of medium redox-potential by 97 and 88 mV in the presence of GA and TA, respectively, which further continued till oxygen depletion (Figure 2E).
When TA was added into aerobically growing cultures in mid-logarithmic phase (OD600 = 0.4), an irreversible decrease of potential of sulfide-specific electrode by about 52 mV (180 nM of S2-ions) was registered during 1h of incubation (Figure 2H) indicating production of sulfide by the cells in response to TA addition.
No significant shifts of extracellular potassium levels were found in the presence of GA and TA (data not shown).
Thus, a sharp drop in Eh after addition of TA and GA and accumulation of sulfide after addition of TA indicate a significant change in redox situation, which might lead to activation of global stress response regulators [10].
After 15 min of GA addition sulA::lacZ expression level sharply increased by about 60% and further remained about 45% higher compared to the cultures not treated with phenolics (Figure 3A). Elevation of expression of gene sulA gene can be used as an indicator of DNA damages and a consequent activation of SOS-response [26]. katG expression also increased in the presence of GA by about 25% (Figure 3B). Rise in katG expression can be used a sign of peroxide stress and activation of oxidative stress response through OxyR regulon [27]. Collectively, these findings revealed contribution of both SOS- and OxyR-regulons in the effects provoked by GA.
Without tested compounds, during 1 h of incubation the wild type and mutant strains showed a similar amount of fluorescent cells with DIBAC (data not shown). TA increased fluorescence in the wild-type by 3 times as well as in pgaA and ydeH mutants. In recA mutant, the increase was 10 times higher compared to the wild-type (Figure 3C). GA did not affect fluorescence in the wild-type during 1 h of incubation. However, it stimulated fluorescence in rpoS and csgA mutants by about 3 times after 30 min exposure to GA. In case of wcaM, 1h after GA addition fluorescence grew up by 2 times compared to the wild-type (Figure 3D).
Previously, we have determined minimum inhibitory concentrations (MICs) for TA and GA which were 1 and 4 mg/mL, respectively, in M9 media with glucose. Interestingly, we had no minimal bactericidal concentration (MBC) and minimal biofilm prevention concentration (MBPC) for TA, while for gallic acid these were 4 mg/mL [16]. These observations revealed distinct effects of the two phenolic compounds on biofilm formation, however redox activity of both is well established showing dual anti- and prooxidant effects [13],[28]. The aim of this work was to elucidate contribution of redox properties of tannic and gallic acids on biofilm formation.
Here, we used sub-MICs of TA and GA to study their effects on biofilms and their counterpart planktonic cultures of the wild-type strain and mutants lacking genes involved in biofilm formation. Incubation of wild-type cultures for 22 h with TA or GA had a bactericidal effect for the plankton but at the same time increased amount of CFU in the biofilms. Taking into account, previously found ability of TA to produce hydrogen peroxide [28] during autooxidation which was also seen here in our real-time monitoring of dO2 and Eh, we concluded that an oxidative stress took place and it could contribute to bactericidal action of TA. However, we did not observe elevation of expression of katG gene responsible for peroxide stress response during 1h incubation with TA. At the same time, about 3-time decrease of the specific growth rate could stimulate general stress response pathways including biofilm formation [10].
In case of GA we observed a real time increase of katG::lacZ, which specifically indicates activation of OxyR regulon in response to peroxide stress [27]. A slight inhibition of respiration and sulA::lacZ activation by GA in real-time also showed activation of SOS-response and DNA damage in the presence of GA [26]. Damage of DNA in vitro by GA was previously described [29]. These effects of GA could contribute to its bactericidal action. Stimulation of mass biofilm formation and increase CFU in the wild-type biofilms that were found here could be an adaptive strategy to escape from remarkable oxidative activity of both GA and TA [30].
Without phenolic compounds, mass and specific biofilm formation were sensitive to pgaA mutation (lack of porin) which in fact blocked release of the main extracellular matrix component - poly-beta-1,6-N-acetyl-D-glucosamine (PGA). However, the amount of CFU in the biofilms increased indicating that cells incapable of PGA synthesis could produce small amounts of biofilm matrix out of other polysaccharides like colanic acid or cellulose [31] and eventually produce a biofilm.
Another important thing to mention is that production of curli might be temperature dependent and is often associated with ambient temperatures. Expression of csgA at 37 °C was observed in E. coli O157:H7 [7]. In our preliminary experiments we used Congo red binding assay [32],[33] in order to check production of curli at 37 °C in E. coli BW25113 and some of its mutant derivatives from the Keio collection. Our results revealed expression of curli in the wild-type. This might sound contradictory as Congo red binding assay was shown to be specific not only to curli production but to other bacterial extracellular features, including cellulose [34]. Therefore, we checked curli expression in the mutant E. coli JW1023 (ΔcsgD), lacking activator of csgBAC operon, and E. coli JW1025 (ΔcsgA), lacking a main protein component of curli, and found no binding activity. Collectively, we could conclude that there was production of curli in the wild-type E. coli BW25113 at 37 °C.
Effects of plant phenolic compounds on genes associated with biofilm formation are quite poorly described. Therefore, our results might provide some new aspects in this field.
In our conditions, TA could overcome inhibitory effect of pgaA mutation on both BF and SBF while GA demonstrated inhibiting effects on BF in pgaA mutants which was similar to earlier described suppression of pgaABC genes by 0.25 mg/mL GA [2].
In case of recA mutant, which had no SOS-response activator, without polyphenols there was no effect on BF, SBF and CFU values. But in the presence of TA, bactericidal action was found which resulted in an increase of SBF. Bactericidal action was also confirmed in the tests with DIBAC where recA mutant remarkably increased percentage of fluorescent cells in the presence of TA. TA was reported to inhibit intracellular SOS-response in E. coli strains [35] which in our case could contribute to an increased bactericidal action of TA in recA mutant. TA and its monomer GA may alter the process of DNA damage in vitro, with a higher DNA degrading capacity for GA [36].
Effects of GA on flagella synthesis were studied in Pseudomonas fluorescens KM120, where 240 μmol/L GA prevented expression of flagella synthesis genes and reduced colonization [37]. In our case, ydeH mutation in E. coli implied low levels of c-di-GMP resulting in disruption of flagella synthesis. However, without tested compounds, ydeH mutant had both large values of BF and CFU, and, consequently, a decreased value of SBF. In the presence of TA ydeH mutant increased BF but decreased CFU (which also coincided with DIBAC test results), increasing SBF. Therefore, TA could also act as bactericidal agent which stimulated biofilm formation as an adaptive response even when flagella were absent.
RpoS is an activator of general stress response in E. coli which is involved in stimulation of biofilm formation as a result of slow growth [38]. Mutations in rpoS are reported to induce biofilm production even in exponentially growing cultures [39]. In our conditions rpoS mutant had BF similar to the wild type but an increased amount of CFU, thus a decreased value of SBF. TA had no effect on BF but increased CFU, diminishing value of SBF. This was consistent with the previously described TA acting on biofilm formation via RpoS-independent pathways [40].
Similarly to rpoS mutant, it occurred in wcaM mutant, lacking an enzyme for colanic acid synthesis. So, we could suppose TA did not affect pathways of synthesis of colanic acid. On the whole, colanic acid was found to be essential for depth and three-dimensional structure of E. coli biofilms but not for surface attachment [41]. Thus, apparently, no significant effects of phenolic compounds on production of biofilms in wcaM mutant were observed.
Production of curli is under RpoS control [42]. In our conditions, csgA mutant lacking main protein component of curli acted similarly to the wild-type in the absence of phenolic compounds. TA did not stimulate BF or CFU in the biofilms in this strain which could be probably due to the lack of effects of TA on RpoS expression [40]. At the same time, GA reduced both BF and CFU in biofilms, increasing SBF in csgA.
Collectively, our data indicate that TA and GA exhibited strong oxidative properties that altered activity of stress regulons and contributed to decrease of CFU and ability of cells to maintain membrane potential. Both TA and GA stimulated BF in all the strains with the exception of the strains deficient in flagella synthesis. Both phenolic compounds demonstrated bactericidal effect which was weakened in biofilms.
TA efficiently killed bacteria in the bioflms of pgaA mutant which pointed out an important role of PGA polysaccharide in matrix formation. Similar effects of TA in recA mutant indicate involvement of SOS-response into reaction towards exposure with TA. These observations rise alert when considering TA a potential anti-biofilm agent because situation seems more complicated: a revealed bactericidal effect of TA eventually switched on a strategy to overcome toxic exposure to TA and increase share of viable cells inside the biofilms.
GA-induced killing was more pronounced in the biofilms of csgA mutant revealing role of curli in protection against GA toxicity.
In conclusion, our findings indicate that motile-sessile transitions in E. coli in the presence of TA and GA are based on dual behaviour of these polyphenols. Their strong oxidative properties switch on pathways that allow persistence to oxidative stress and survival of cells inside biofilms.
[1] |
Siegel RL, Miller KD, Jemal A (2016) Cancer statistics, 2016. CA Cancer J Clin 66: 7-30. doi: 10.3322/caac.21332
![]() |
[2] |
Ying H, Dey P, Yao W, et al. (2016) Genetics and biology of pancreatic ductal adenocarcinoma. Genes Dev 30: 355-385. doi: 10.1101/gad.275776.115
![]() |
[3] |
Rebelo A, Molpeceres J, Rijo P, et al. (2017) Pancreatic Cancer Therapy Review: from classic therapeutic agents to modern nanotechnologies. Curr Drug Metab 18: 346-359. doi: 10.2174/1389200218666170201151135
![]() |
[4] |
Fogel EL, Shahda S, Sandrasegaran K, et al. (2017) A Multidisciplinary Approach to Pancreas Cancer in 2016: A Review. Am J Gastroenterol 112: 537-554. doi: 10.1038/ajg.2016.610
![]() |
[5] |
Turek M, Krzyczmonik M, Bałczewski P (2016) New hopes in cancer battle - a review of new molecules and treatment strategies. Med Chem 12: 700-719. doi: 10.2174/1573406412666160502153700
![]() |
[6] |
Millimouno FM, Dong J, Yang L, et al. (2014) Targeting apoptosis pathways in cancer and perspectives with natural compounds from mother nature. Cancer Prev Res (Phila) 7: 1081-1107. doi: 10.1158/1940-6207.CAPR-14-0136
![]() |
[7] |
Naviglio S, Della Ragione F (2013) Naturally occurring molecules and anticancer combination therapies in the era of personalized medicine and economic crisis. Curr Pharm Des 19: 5325-5326. doi: 10.2174/1381612811319300001
![]() |
[8] |
Shanmugam MK, Lee JH, Chai EZ, et al. (2016) Cancer prevention and therapy through the modulation of transcription factors by bioactive natural compounds. Semin Cancer Biol 40-41: 35-47. doi: 10.1016/j.semcancer.2016.03.005
![]() |
[9] |
Sapio L, Gallo M, Illiano M, et al. (2017) The natural cAMP elevating compound forskolin in cancer therapy: Is it time? J Cell Physiol 232: 922-927. doi: 10.1002/jcp.25650
![]() |
[10] |
Kanne H, Burte NP, Prasanna V, et al. (2015) Extraction and elemental analysis of Coleus forskohlii extract. Pharmacognosy Res 7: 237-241. doi: 10.4103/0974-8490.157966
![]() |
[11] |
Godard MP, Johnson BA, Richmond SR (2005) Body composition and hormonal adaptations associated with forskolin consumption in overweight and obese men. Obes Res 13: 1335-1343. doi: 10.1038/oby.2005.162
![]() |
[12] |
Henderson S, Magu B, Rasmussen C, et al. (2005) Effects of Coleus forskohlii supplementation on body composition and hematological profiles in mildly overweight women. J Int Soc Sports Nutr 2: 54-62. doi: 10.1186/1550-2783-2-2-54
![]() |
[13] |
Loftus HL, Astell KJ, Mathai M, et al. (2015) Coleus forskohlii Extract Supplementation in Conjunction with a Hypocaloric Diet Reduces the Risk Factors of Metabolic Syndrome in Overweight and Obese Subjects: A Randomized Controlled Trial. Nutrients 7: 9508-9522. doi: 10.3390/nu7115483
![]() |
[14] |
Beavo JA, Brunton LL (2002) Cyclic nucleotide research -- still expanding after half a century. Nat Rev Mol Cell Biol 3: 710-718. doi: 10.1038/nrm911
![]() |
[15] |
Gancedo JM (2013) Biological roles of cAMP: variations on a theme in the different kingdoms of life. Biol Rev Camb Philos Soc 88: 645-668. doi: 10.1111/brv.12020
![]() |
[16] |
Pattabiraman DR, Bierie B, Kober KI, et al. (2016) Activation of PKA leads to mesenchymal-to-epithelial transition and loss of tumor-initiating ability. Science 351: aad3680. doi: 10.1126/science.aad3680
![]() |
[17] |
Follin-Arbelet V, Misund K, Hallan Naderi E, et al. (2015) The natural compound forskolin synergizes with dexamethasone to induce cell death in myeloma cells via BIM. Sci Rep 5: 13001. doi: 10.1038/srep13001
![]() |
[18] |
Naviglio S, Di Gesto D, Illiano F, et al. (2010) Leptin potentiates antiproliferative action of cAMP elevation via protein kinase A down-regulation in breast cancer cells. J Cell Physiol 225: 801-809. doi: 10.1002/jcp.22288
![]() |
[19] |
Dong H, Claffey KP, Brocke S, et al. (2015) Inhibition of breast cancer cell migration by activation of cAMP signaling. Breast Cancer Res Treat 152: 17-28. doi: 10.1007/s10549-015-3445-9
![]() |
[20] |
Park JY, Juhnn YS (2016) cAMP signaling increases histone deacetylase 8 expression by inhibiting JNK-dependent degradation via autophagy and the proteasome system in H1299 lung cancer cells. Biochem Biophys Res Commun 470: 336-342. doi: 10.1016/j.bbrc.2016.01.049
![]() |
[21] |
Cristóbal I, Rincón R, Manso R, et al. (2014) Hyperphosphorylation of PP2A in colorectal cancer and the potential therapeutic value showed by its forskolin-induced dephosphorylation and activation. Biochim Biophys Acta 1842: 1823-1829. doi: 10.1016/j.bbadis.2014.06.032
![]() |
[22] |
Burdyga A, Conant A, Haynes L, et al. (2013) cAMP inhibits migration, ruffling and paxillin accumulation in focal adhesions of pancreatic ductal adenocarcinoma cells: effects of PKA and EPAC. Biochim Biophys Acta 1833: 2664-2672. doi: 10.1016/j.bbamcr.2013.06.011
![]() |
[23] |
Quinn SN, Graves SH, Dains-McGahee C, et al. (2017) Adenylyl cyclase 3/adenylyl cyclase-associated protein 1 (CAP1) complex mediates the anti-migratory effect of forskolin in pancreatic cancer cells. Mol Carcinog 56: 1344-1360. doi: 10.1002/mc.22598
![]() |
[24] |
Spina A, Di Maiolo F, Esposito A, et al. (2012) cAMP Elevation Down-Regulates β3 Integrin and Focal Adhesion Kinase and Inhibits Leptin-Induced Migration of MDA-MB-231 Breast Cancer Cells. Biores Open Access 1: 324-332. doi: 10.1089/biores.2012.0270
![]() |
[25] |
Sapio L, Sorvillo L, Illiano M, et al. (2015) Inorganic Phosphate Prevents Erk1/2 and Stat3 Activation and Improves Sensitivity to Doxorubicin of MDA-MB-231 Breast Cancer Cells. Molecules 20: 15910-15928. doi: 10.3390/molecules200915910
![]() |
[26] | Crowley LC, Scott AP, Marfell BJ, et al. (2016) Measuring Cell Death by Propidium Iodide Uptake and Flow Cytometry. Cold Spring Harb Protoc 2016: pdb.prot087163. |
[27] |
Thoennissen NH, Iwanski GB, Doan NB, et al. (2009) Cucurbitacin B induces apoptosis by inhibition of the JAK/STAT pathway and potentiates antiproliferative effects of gemcitabine on pancreatic cancer cells. Cancer Res 69: 5876-5884. doi: 10.1158/0008-5472.CAN-09-0536
![]() |
[28] |
Zhang Q, Wang H, Ran L, et al. (2016) The preclinical evaluation of TIC10/ONC201 as an anti-pancreatic cancer agent. Biochem Biophys Res Commun 476: 260-266. doi: 10.1016/j.bbrc.2016.05.106
![]() |
[29] |
Nagaraju GP, Mezina A, Shaib WL, et al. (2016) Targeting the Janus-activated kinase-2-STAT3 signalling pathway in pancreatic cancer using the HSP90 inhibitor ganetespib. Eur J Cancer 52: 109-119. doi: 10.1016/j.ejca.2015.10.057
![]() |
[30] | Jung KH, Yan HH, Fang Z, et al. (2014) HS-104, a PI3K inhibitor, enhances the anticancer efficacy of gemcitabine in pancreatic cancer. Int J Oncol 45: 311-321. |
[31] |
Zimmerman NP, Roy I, Hauser AD, et al. (2015) Cyclic AMP regulates the migration and invasion potential of human pancreatic cancer cells. Mol Carcinog 54: 203-215. doi: 10.1002/mc.22091
![]() |
[32] |
Lee BY, Timpson P, Horvath LG, et al. (2015) FAK signaling in human cancer as a target for therapeutics. Pharmacol Ther 146: 132-149. doi: 10.1016/j.pharmthera.2014.10.001
![]() |
[33] |
Canel M, Serrels A, Frame MC, et al. (2013) E-cadherin-integrin crosstalk in cancer invasion and metastasis. J Cell Sci 126: 393-401. doi: 10.1242/jcs.100115
![]() |
[34] |
Lieberman MD, Paty P, Li XK, et al. (1996) Elevation of intracellular cyclic adenosine monophosphate inhibits the epidermal growth factor signal transduction pathway and cellular growth in pancreatic adenocarcinoma cell lines. Surgery 120: 354-359. doi: 10.1016/S0039-6060(96)80309-6
![]() |
[35] |
Burris HA 3rd, Moore MJ, Andersen J, et al. (1997) Improvements in survival and clinical benefit with gemcitabine as first-line therapy for patients with advanced pancreas cancer: a randomized trial. J Clin Oncol 15: 2403-2413. doi: 10.1200/JCO.1997.15.6.2403
![]() |
[36] |
Ellenrieder V, König A, Seufferlein T (2016) Current Standard and Future Perspectives in First- and Second-Line Treatment of Metastatic Pancreatic Adenocarcinoma. Digestion 94: 44-49. doi: 10.1159/000447739
![]() |
[37] | Moon SU, Kim JW, Sung JH, et al. (2015) p21-Activated Kinase 4 (PAK4) as a Predictive Marker of Gemcitabine Sensitivity in Pancreatic Cancer Cell Lines. Cancer Res Treat 47: 501-508. |
[38] | Sumiyoshi H, Matsushita A, Nakamura Y, et al. (2016) Suppression of STAT5b in pancreatic cancer cells leads to attenuated gemcitabine chemoresistance, adhesion and invasion. Oncol Rep 35: 3216-3226. |
[39] | Miao X, Koch G, Ait-Oudhia S, et al. (2016) Pharmacodynamic Modeling of Cell Cycle Effects for Gemcitabine and Trabectedin Combinations in Pancreatic Cancer Cells. Front Pharmacol 7: 421. |
[40] |
Morgan MA, Parsels LA, Parsels JD, et al. (2005) Role of checkpoint kinase 1 in preventing premature mitosis in response to gemcitabine. Cancer Res 65: 6835-6842. doi: 10.1158/0008-5472.CAN-04-2246
![]() |
[41] |
Zhang JG, Hong DF, Zhang CW, et al. (2014) Sirtuin 1 facilitates chemoresistance of pancreatic cancer cells by regulating adaptive response to chemotherapy-induced stress. Cancer Sci 105: 445-454. doi: 10.1111/cas.12364
![]() |
[42] |
Pan Y, Zheng M, Zhong L, et al. (2015) A preclinical evaluation of SKLB261, a multikinase inhibitor of EGFR/Src/VEGFR2, as a therapeutic agent against pancreatic cancer. Mol Cancer Ther 14: 407-418. doi: 10.1158/1535-7163.MCT-14-0485
![]() |
[43] | Ozaki T, Nakamura M, Ogata T, et al. (2016) Depletion of pro-oncogenic RUNX2 enhances gemcitabine (GEM) sensitivity of p53-mutated pancreatic cancer Panc-1 cells through the induction of pro-apoptotic TAp63. Oncotarget 7: 71937-71950. |
[44] |
Mann KM, Ying H, Juan J, et al. (2016) KRAS-related proteins in pancreatic cancer. Pharmacol Ther 168: 29-42. doi: 10.1016/j.pharmthera.2016.09.003
![]() |
[45] | Wu P, Wu D, Zhao L, et al. (2016) Prognostic role of STAT3 in solid tumors: a systematic review and meta-analysis. Oncotarget 7: 19863-19883. |
[46] |
Singh NS, Bernier M, Wainer IW (2016) Selective GPR55 antagonism reduces chemoresistance in cancer cells. Pharmacol Res 111: 757-766. doi: 10.1016/j.phrs.2016.07.013
![]() |
[47] |
He X, Wang J, Wei W, et al. (2016) Hypoxia regulates ABCG2 activity through the activation of ERK1/2/HIF-1α and contributes to chemoresistance in pancreatic cancer cells. Cancer Biol Ther 17: 188-198. doi: 10.1080/15384047.2016.1139228
![]() |
[48] |
Chai X, Chu H, Yang X, et al. (2015) Metformin Increases Sensitivity of Pancreatic Cancer Cells to Gemcitabine by Reducing CD133+ Cell Populations and Suppressing ERK/P70S6K Signaling. Sci Rep 5: 14404. doi: 10.1038/srep14404
![]() |
[49] |
Vena F, Li Causi E, Rodriguez-Justo M, et al. (2015) The MEK1/2 Inhibitor Pimasertib Enhances Gemcitabine Efficacy in Pancreatic Cancer Models by Altering Ribonucleotide Reductase Subunit-1 (RRM1). Clin Cancer Res 21: 5563-5577. doi: 10.1158/1078-0432.CCR-15-0485
![]() |
[50] |
Lee J, Han SI, Yun JH, et al. (2015) Quercetin 3-O-glucoside suppresses epidermal growth factor-induced migration by inhibiting EGFR signaling in pancreatic cancer cells. Tumour Biol 36: 9385-9393. doi: 10.1007/s13277-015-3682-x
![]() |
[51] |
Wang M, Lu X, Dong X, et al. (2015) pERK1/2 silencing sensitizes pancreatic cancer BXPC-3 cell to gemcitabine-induced apoptosis via regulating Bax and Bcl-2 expression. World J Surg Oncol 13: 66. doi: 10.1186/s12957-015-0451-7
![]() |
[52] |
Zheng C, Jiao X, Jiang Y, et al. (2013) ERK1/2 activity contributes to gemcitabine resistance in pancreatic cancer cells. J Int Med Res 41: 300-306. doi: 10.1177/0300060512474128
![]() |
[53] |
Tang Y, Liu F, Zheng C, et al. (2012) Knockdown of clusterin sensitizes pancreatic cancer cells to gemcitabine chemotherapy by ERK1/2 inactivation. J Exp Clin Cancer Res 31: 73. doi: 10.1186/1756-9966-31-73
![]() |
[54] | Venkatasubbarao K, Peterson L, Zhao S, et al. (2013) Inhibiting signal transducer and activator of transcription-3 increases response to gemcitabine and delays progression of pancreatic cancer. Mol Cancer 12: 104. |
[55] |
Li L, Leung PS (2014) Use of herbal medicines and natural products: an alternative approach to overcoming the apoptotic resistance of pancreatic cancer. Int J Biochem Cell Biol 53: 224-236. doi: 10.1016/j.biocel.2014.05.021
![]() |
[56] |
Vendrely V, Peuchant E, Buscail E, et al. (2017) Resveratrol and capsaicin used together as food complements reduce tumor growth and rescue full efficiency of low dose gemcitabine in a pancreatic cancer model. Cancer Lett 390: 91-102. doi: 10.1016/j.canlet.2017.01.002
![]() |
[57] | Ren X, Zhao W, Du Y, et al. (2016) Activator protein 1 promotes gemcitabine-induced apoptosis in pancreatic cancer by upregulating its downstream target Bim. Oncol Lett 12: 4732-4738. |
[58] |
Finbloom DS, Larner AC (1995) Regulation of the Jak/STAT signalling pathway. Cell Signal 7: 739-745. doi: 10.1016/0898-6568(95)02004-7
![]() |
[59] | Yuan J, Zhang F, Niu R (2015) Multiple regulation pathways and pivotal biological functions of STAT3 in cancer. Sci Rep 5: 17663. |
[60] |
Li MX, Bi XY, Huang Z, et al. (2015) Prognostic Role of Phospho-STAT3 in Patients with Cancers of the Digestive System: A Systematic Review and Meta-Analysis. PLoS One 10: e0127356. doi: 10.1371/journal.pone.0127356
![]() |
[61] |
Zulkifli AA, Tan FH, Putoczki TL, et al. (2017) STAT3 signaling mediates tumour resistance to EGFR targeted therapeutics. Mol Cell Endocrinol 451: 15-23. doi: 10.1016/j.mce.2017.01.010
![]() |
[62] | Zhao C, Li H, Lin HJ, et al. (2015) Feedback Activation of STAT3 as a Cancer Drug-Resistance Mechanism. Trends Pharmacol Sci 37: 47-61. |
[63] |
Johnston PA, Grandis JR (2011) STAT3 signaling: anticancer strategies and challenges. Mol Interv 11: 18-26. doi: 10.1124/mi.11.1.4
![]() |
[64] |
Furtek SL, Backos DS, Matheson CJ, et al. (2016) Strategies and Approaches of Targeting STAT3 for Cancer Treatment. ACS Chem Biol 11: 308-318. doi: 10.1021/acschembio.5b00945
![]() |
[65] | Furukawa T (2015) Impacts of activation of the mitogen-activated protein kinase pathway in pancreatic cancer. Front Oncol 5: 23. |
[66] |
Neuzillet C, Hammel P, Tijeras-Raballand A, et al. (2013) Targeting the Ras-ERK pathway in pancreatic adenocarcinoma. Cancer Metastasis Rev 32: 147-162. doi: 10.1007/s10555-012-9396-2
![]() |
[67] |
Spina A, Di Maiolo F, Esposito A, et al. (2013) Integrating leptin and cAMP signalling pathways in triple-negative breast cancer cells. Front Biosci (Landmark Ed) 18: 133-144. doi: 10.2741/4092
![]() |
[68] |
Follin-Arbelet V, Torgersen ML, Naderi EH, et al. (2013) Death of multiple myeloma cells induced by cAMP-signaling involves downregulation of Mcl-1 via the JAK/STAT pathway. Cancer Lett 335: 323-331. doi: 10.1016/j.canlet.2013.02.042
![]() |
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