Effect Of Metformin In Combination Research Articles

Combined effects of metformin and photobiomodulation improve the proliferation phase of wound healing in type 2 diabetic rats

We determined the impact of Photobiomodulation (PBM) and metformin administration alone and combined on the inflammation and proliferation steps of wound healing of incisions in type two diabetes mellitus (T2DM) rats. 40 rats were divided into 4 groups (n = 10 each group). A non-genetic model of T2DM was induced in all rats, and an incision was made on each rat. There were 4 groups as follows: Group 1 was control group. Group 2 received PBM alone (890 nm, 80 Hz, 0.324 J/cm2, daily). Group 3 received metformin alone (50 mg/kg, i.p., daily) and the fourth group received combination of PBM + metformin. At inflammation (day 4) and proliferation (day 7) steps, tensiometerical, stereological, and immunohistochemical examinations were performed. PBM and PBM + metformin treatments significantly increased wound strength at inflammation and proliferation steps of wound healing respectively. PBM, metformin, and PBM + metformin groups significantly decreased inflammatory cells at inflammation and proliferation steps of wound healing. PBM, metformin, and PBM + metformin groups significantly improved granulation tissue formation by increasing fibroblasts, and new blood vessel formation at inflammation and proliferation steps of wound healing. Metformin significantly increased M2 macrophages than other treatment groups at inflammation and proliferation steps of wound healing. Simultaneously, PBM significantly decreased M2 macrophages than control group. We concluded PBM and PBM + metformin treatments significantly hastened repair at the inflammation and proliferation steps of repairing skin injury in a non-genetic model of T2 DM. PBM + metformin showed a synergistic impact. There were not a positive relation between M2 macrophage number and wound strength in the studied groups. The details of the molecular mechanisms of PBM, and PBM + metformin treatments of repairing wounds in animals, and treatment of DFUs of patients with T2 DM should be elucidated by further research.

1129P - Window of opportunity for durvalumab (MEDI4736) plus metformin trial in squamous cell carcinoma of the head and neck (SCCHN): Interim safety analysis

BackgroundDespite the application of PD-1 inhibitors in clinical practice in SCCHN, only a fraction of patients shows durable responses to monotherapy. Numerous combinatorial strategies have been utilized to attempt to augment immunotherapy efficacy. While dysregulated tumour metabolism (TM) is a critical feature of the tumour microenvironment (TME) and impacts immune function within the TME, much remains to be done to bridge these areas and explore therapeutic opportunities. Recent murine xenograft and clinical translational data suggests that metformin alters TM, and preclinical data suggests possible potentiation of PD-1 axis inhibition by metformin. MethodsThis is a single-center, randomized trial for patients with all stages of resectable SCCHN, with planned enrollment of 38 patients. Part 1, which has been completed, was a safety run-in with 6 patients treated with metformin (met) + durvalumab (durva) for safety evaluation. Part 2 will enroll 32 additional patients with a 3:1 randomization to treatment arm A (met 1000mg BID Day 1-31 + durva 1500mg IV x 1 on Day 3) and treatment arm B (durva 1500mg IV x 1). Tumor and blood will be collected pre and post treatment with analysis of immune cell composition. The primary endpoint is the combined effect of metformin and durvalumab on the immune TME, specifically with respect to alterations in T cell and macrophage polarization. Secondary endpoints include safety and tolerability, alterations in immunohistochemical markers of the TME, transcriptome and circulating DNA analysis, and objective response rate. ResultsSix patients were enrolled in Part 1. All were males with a mean age of 65.7±6.8 years. All patients had grade 1 adverse events (AE) consisting mainly of gastrointestinal (diarrhea, nausea, or abdominal cramps) and constitutional (anorexia, fatigue, or sleep disturbance) symptoms. No patient experienced AE>= grade 2. All patients were able to proceed to surgery without unanticipated delays. ConclusionsThe combination of met and durva was safe in the first cohort of patients. Enrollment for Part 2 is ongoing. Clinical trial identificationNCT03618654. Legal entity responsible for the studySidney Kimmel Cancer Center at Thomas Jefferson University Sidney Kimmel Cancer Center at Thomas Jefferson University Sidney Kimmel Cancer Center at Thomas Jefferson University Sidney Kimmel Cancer Center at Thomas Jefferson University. FundingSidney Kimmel Cancer Center at Thomas Jefferson University. DisclosureJ.M. Johnson: Research grant / Funding (self): Bristol-Myers Squibb. A. Argiris: Advisory / Consultancy, Speaker Bureau / Expert testimony, Travel / Accommodation / Expenses: Merck Serono; Advisory / Consultancy, Speaker Bureau / Expert testimony, Research grant / Funding (self), Travel / Accommodation / Expenses: Bristol-Myers Squibb; Advisory / Consultancy: Roche; Advisory / Consultancy: Debiopharm Group; Advisory / Consultancy: Aspyrian Therapeutics; Research grant / Funding (self): Genentech/Roche. A. Luginbuhl: Research grant / Funding (self): Bristol-Myers Squibb. R. Zinner: Research grant / Funding (institution), Travel / Accommodation / Expenses, Shareholder / Stockholder / Stock options, Full / Part-time employment, An Immediate Family Member: Merck; Research grant / Funding (institution), Travel / Accommodation / Expenses: Bristol-Myers Squibb; Travel / Accommodation / Expenses: Lilly. U. Rodeck: Shareholder / Stockholder / Stock options: Akriveia Therapeutics; Research grant / Funding (self): Advaxis; Licensing / Royalties: Several Patents. J.M. Curry: Research grant / Funding (self): AstraZeneca. All other authors have declared no conflicts of interest.

Metformin combined with nelfinavir induces SIRT3/mROS-dependent autophagy in human cervical cancer cells and xenograft in nude mice

The molecular mechanisms underlying the antineoplastic properties of metformin combined with nelfinavir remain elusive. To explore this question, transmission electron microscopy (TEM) was used to observe the combinatorial effect of inducing autophagosome formation in human cervical cancer cells. Western blotting respectively assayed protein expression of LC3I, LC3II, Beclin-1, Autophagy-related protein 7 (Atg7), Autophagy-related protein 3 (Atg3), NAD-dependent deacetylase sirtuin-3 (SIRT3) and major histocompatibility complex class I chain-related gene A (MICA). Lactate dehydrogenase (LDH) cytotoxicity assay evaluated natural killer (NK) cell cytotoxicity in the presence of metformin and nelfinavir in combination or each drug alone. Using tumor xenografts in a nude mouse model, antitumor efficacy of the drug combination was assessed. We found that the drug combination could induce autophagosome formation in human cervical cancer cells. The biomarker proteins of autophagy, including Beclin-1, Atg7 and Atg3, decreased, but the ratios of LC3I/II increased. We also found that this drug combination sensitizes human cervical cancer cells to NK cell-mediated lysis by increasing the protein of SIRT3 and MICA. Moreover, this drug combination markedly induced autophagy of SiHa xenografts in nude mice. Therefore, it can be concluded that metformin, in combination with nelfinavir, can induce SIRT3/mROS-dependent autophagy and sensitize NK cell-mediated lysis in human cervical cancer cells and cervical cancer cell xenografts in nude mice. Thus, our findings have revealed the detailed molecular mechanisms underlying the antitumor effects of metformin in combination with nelfinavir in cervical cancer.

Anti-diabetic effect of metformin combined with peanut (Arachis hypogaea L.) on streptozotocin induced diabetic rats

Background: Diabetes mellitus (DM) is a common metabolic disorder. Metformin is the initial drug of choice for treatment of type 2 DM. In many cases, metformin mono-therapy cannot effectively achieve the targeted glycemic control. However, metformin along with peanut (Arachis hypogaea L.) may reduce blood glucose level more effectively.
 Objective: To evaluate the anti-diabetic effect of metformin in combination with peanut on streptozotocin induced diabetic rats.
 Methods: This experimental study was conducted in the Department of Physiology, Sir Salimullah Medical College, in 2016. Forty (40) Wistar Albino male rats, 90-120 days old, weighing 225-240 g (initial body weight) were taken and divided into four groups containing 10 rats in each group, i.e. Non-diabetic group (ND), Streptozotocin induced diabetic group (STZ), Diabetic group treated with metformin (STZ-M) and Diabetic group treated with metformin and peanut (STZ-MP). Diabetic model was developed by giving single intraperitoneal injection of streptozotocin (50mg/kg body weight) to STZ, STZ-M and STZ-MP groups on day-1. In addition, STZ-M group received metformin (500mg/kg body weight) orally and STZ-MP group received both metformin and peanut extract orally (both 500mg/kg body weight) once daily in the morning for 21 days (day-4 to day-24). After measuring the final body weight, rats were sacrificed on day-25. To observe glycemic status, Fasting Blood Glucose (FBG), serum insulin levels were estimated and HOMA-IR was calculated. Statistical analyses were done by one way ANOVA and Bonferroni test as applicable.
 Results: Mean FBG level and HOMA-IR were significantly (p<0.001) higher and serum insulin level and final body weight were significantly (p<0.001) lower in STZ group when compared to those of ND group. Whereas, FBG level and HOMA-IR were significantly (p<0.001) lower and insulin level and final body weight were significantly higher (p<0.001) in both STZ-M and STZ-MP groups in comparison to those of STZ group but more profound effects were found in STZ-MP group than those of STZ-M group.
 Conclusion: The present study revealed that, metformin combined with peanut was more effective to control glycemic status in diabetic rats than metformin alone.
 J Bangladesh Soc Physiol. 2018, December; 13(2): 59-67

Efficacy of metformin in combination with immune checkpoint inhibitors (anti-PD-1/anti-CTLA-4) in metastatic malignant melanoma

BackgroundMetformin is one of the biguanides commonly used in patients with type II Diabetes Mellitus. Apart from its hypoglycemic properties, metformin also inhibits the cell cycle by restricting protein synthesis and cell proliferation via regulating the LKB1/AMPL pathway. Furthermore, it also enhances the PD-1 blockade through a reduction of tumor hypoxia. Metformin has shown a significant favorable impact on treatment-related outcomes in solid tumors, but these outcomes have not been replicated in the limited clinical studies done on malignant melanoma. Moreover, none of these studies have reported on the efficacy of the combined use of metformin and immune checkpoint inhibitors (ICIs).MethodsThis is a retrospective cohort study that includes patients diagnosed with metastatic malignant melanoma and treated with ipilimumab, nivolumab, and/or pembrolizumab (Cohort A); or ipilimumab, nivolumab, and/or pembrolizumab plus metformin (Cohort B) between January 1st 2011 through December 15th 2017. In this study, patients are stratified based on anti-PD-1 only and anti-CTLA4/anti-PD-1 combination therapies in each cohort. Objective response rate (ORR) is the primary endpoint. Disease control rate (DCR), overall survival (OS) and progression-free survival (PFS) are the secondary endpoints.ResultsCohort A had 33 patients (60%), while cohort B had 22 (40%). Overall patient characteristics were similar between both cohorts. ORR was higher in cohort B (68.2% vs. 54.5%, P = 0.31). The DCR was higher in cohort B as well (77.3% vs. 60.6%, P = 0.19). Median OS (46.7 months vs. 28 months), and median PFS (19.8 months vs. 5 months) were longer in cohort B. However, on univariate and multivariate analyses, none of these differences were statistically significant. The mean number of new metastatic sites which appeared during therapy were significantly higher in cohort A (A:1.51 vs. B:0.59, P = 0.009).ConclusionWe have observed favorable treatment-related outcomes (ORR, DCR, median PFS and median OS) in patients who have received metformin in combination with ICIs without reaching significance, probably, due to small sample size. Hence, large prospective clinical trials are required to study the synergistic effect of metformin in combination with ICIs before it can be recommended as routine additive therapy.

Combined effect of metformin with ascorbic acid versus acetyl salicylic acid on diabetes-related cardiovascular complication; a 12-month single blind multicenter randomized control trial

BackgroundWe aimed to investigate the efficacy of ascorbic acid and acetylsalicylic acid among type II diabetes mellitus patients using metformin (only) for diabetes management therapy.MethodA 12-month single blinded multicenter randomized control trial was designed to investigate the measured variables [Glycated Hemoglobin (HbA1c), Renal function, Albumin Creatinine Ratio (ACR) etc.]. The trial was randomized into 2 experimental parallel arms (ascorbic acid vs acetylsalicylic acid) were blinded with study supplements in combination with metformin and findings were compared to control arm with metformin alone and blinded with placebo. Withdrawal criteria was defined to maintain the equity and balance in the participants in the whole trial.FindingPatients with metformin and ascorbic acid (parallel arm I) was twice more likely to reduce HbA1c than metformin alone (control arm) in a year (OR 2.31 (95% CI 1.87–4.42) p < 0.001). Also Parallel arm I was ten times more likely to reduced risk factors contributing to long-term diabetes complications than participants of arm II in a year (OR 10.38 (95% CI 6.91–15.77) p < 0.001). In contrast, parallel arm II patients were seven times more effective to reduce the risk of expected CVD development in 10 years than arm I (OR 7.54 (95% CI 3.76–10.32) p < 0.001).ConclusionsThe trial concluded that ascorbic acid with metformin is more effective against reducing risks for diabetes related long-term complications (including ACR).TRIAL details Registration No: NTR-6100, Registry Name: Netherlands Trial Registry, URL: http://www.trialregister.nl/trialreg/admin/rctview.asp?TC=6100, Date of Registration: 20th October, 2016, Date of first Enrollment: 1 November, 2015.

Metformin enhances the cytotoxicity of 5-aminolevulinic acid-mediated photodynamic therapy in vitro.

The biguanide metformin is a drug widely used for the treatment of type 2 diabetes. Metformin enhances the cytotoxicity of chemotherapy by promoting the adenosine monophosphate-activated protein kinase (AMPK) autophagy signaling pathway. Photodynamic therapy (PDT) with 5-aminolevulinic acid (5-ALA), a precursor of protoporphyrin IX (PpIX), leads to apoptosis when PpIX accumulates in the mitochondria, and also leads to autophagy through activation of AMPK. In the present study, the effect of metformin in combination with 5-ALA-PDT was evaluated in vitro in KLN205 lung cancer cells. At a fluence of 5 J/cm2, 5-ALA-PDT in combination with 5 mM metformin exhibited significantly increased cytotoxicity compared with that observed with 0 and 0.1 mM metformin (P=0.0197 and P=0.0423, respectively). The cells treated with 5-ALA-PDT and metformin exhibited condensation of nuclear chromatin and the presence of autophagosomes. These results indicate that apoptosis and autophagy occur in KLN205 cells following combined treatment with 5-ALA-PDT and metformin. The results from the present study are the first to indicate, to the best of our knowledge, that metformin potentiates the efficacy of 5-ALA-PDT.

Abstract 1434: Diabetic metastatic castration-resistant prostate cancer patients administered metformin during docetaxel chemotherapy have improved prostate cancer-specific and overall survival

Abstract Introduction and Objective: Docetaxel (DTX) chemotherapy is currently one of the only treatment options for patients with metastatic castration-resistant prostate cancer (mCRPC). Although DTX treatment has been shown to provide survival benefits, it is not curative. Thus, there is a continued need to improve the therapeutic options available for mCRPC patients. One approach is combining DTX with other agents that enhance its effectiveness (i.e. chemosensitizers). Metformin, a commonly prescribed and well-tolerated oral biguanide used to treat type II diabetes, has been shown to exert anti-neoplastic effects in several types of solid tumors, including prostate cancer. More specifically, metformin has been shown to improve the efficacy of chemotherapy in breast cancer and colon cancer models. Niraula et al (2013) evaluated the effect of metformin combined with DTX in prostate cancer patients who participated in the TAX 327 trial. Metformin did not have a statistically significant additive or synergistic effect with docetaxel, but only 38 patients were included in the analysis. There is very limited data examining the combined effect of metformin and DTX in prostate cancer patients. Therefore, the objective of this study is to determine if diabetic mCRPC patients administered metformin during DTX treatment have improved prostate cancer-specific (PCa-specific) and overall survival (OS) when compared to nondiabetic mCRPC patients receiving DTX therapy. Methods: The primary objective of this retrospective study is to analyze patient data from the Ontario Cancer Registry (OCR), Ontario Diabetes Database (ODD), Canadian Institute for Health Information Discharge Abstract Database (CIHI DAD), National Ambulatory Care Reporting System (NACRS), Ontario Health Insurance Plan (OHIP), and the Registered Persons Database (RPDB) evaluate whether there is a difference in PCa-specific and OS between diabetic mCRPC patients administered metformin during DTX treatment and non-diabetic mCRPC patients receiving DTX treatment. The databases described previously are all accessible through the Institute for Clinical Evaluative Sciences (ICES) in Ontario, Canada. Data has been collected and linked at ICES and a research-ready, anonymized dataset has been provided to our research group. Since receiving access to the dataset from ICES, statistical analysis (including multivariate Cox proportional hazards regression, logrank test, and Kaplan Meier survival curves) is in progress using SAS software. Results and Conclusions: Data analysis is currently in progress. If metformin is shown to have a chemosensitizing effect in diabetic mCRPC patients, this would indicate a novel therapeutic approach that is needed for this patient population. Citation Format: Michelle Mayer, Laurence Klotz, Vasundara Venkateswaran. Diabetic metastatic castration-resistant prostate cancer patients administered metformin during docetaxel chemotherapy have improved prostate cancer-specific and overall survival. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1434.

Metformin and pancreatic cancer: Is there a role?

Pancreatic cancer is the fourth leading cause of cancer-related deaths in the USA, with a 5-year survival rate of 6%. Anti-hyperglycemic treatments for type 2 diabetes mellitus that induce hyperinsulinemia (i.e., sulfonylureas) are thought to increase cancer risk, whereas treatments that lower insulin resistance and hyperinsulinemia (i.e., metformin) are considered cancer prevention strategies. Metformin is a cornerstone in the treatment of diabetes mellitus type 2. Retrospective studies have shown a survival benefit in diabetic patients with many solid tumors including pancreatic cancer that have been treated with metformin compared with patients treated with insulin or sulfonylureas. Metformin influences various cellular pathways, including activation of the LKB1/AMPK pathway, inhibition of cell division, promotion of apoptosis and autophagy, down-regulation of circulating insulin, and activation of the immune system. Ongoing research is redefining our understanding about how metformin modulates the molecular pathways implicated in pancreatic cancer. The authors review the topic critically and also give their opinion. Further studies investigating the effect of metformin in combination with chemotherapy, targeted agents, or radiation therapy are undergoing. In addition, the role of metabolic and other biomarkers is needed.

The Effect of Metformin on Adolescents with Type 1 Diabetes: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.

Background. The effect of metformin in combination with insulin in adolescents with type 1 diabetes (T1DM) is controversial. Methods and Results. The PubMed and EMBASE online databases were searched. Five double-blind randomized controlled trials (RCTs) that included 301 adolescents with T1DM were identified. Metformin plus insulin was associated with reduced hemoglobin A1C levels, total daily insulin dosage, body mass index (BMI), and body weight. However, the subgroup analysis demonstrated that HbA1c levels were not significantly changed in overweight/obese adolescents and were significantly reduced in the general patients. On the contrary, BMI and body weight were significantly reduced in overweight/obese adolescents but not in the general patients. Metformin was associated with higher incidence of adverse events. Conclusions. Among adolescents with T1DM, administering adjunctive metformin therapy in addition to insulin was associated with improved HbA1c levels, total daily insulin dosage, BMI, and body weight. However, there may be differences in the effects of this regimen between overweight/obese and nonobese adolescents. The risk of an adverse event may be increased with metformin treatment. These results provide strong evidence supporting future high-quality, large-sample trials.

Synergistic effects of metformin in combination with EGFR-TKI in the treatment of patients with advanced non-small cell lung cancer and type 2 diabetes

BackgroundAcquired resistance has become the bottleneck affecting the efficacy of epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) treatment. Studies have shown that the antidiabetic drug metformin could effectively increase the sensitivity of TKI-resistant lung cancer cells to EGFR-TKI. This study aimed to evaluate the effect of metformin in combination with EGFR-TKI on the prognosis of non-small cell lung cancer (NSCLC) patients with diabetes mellitus type 2 (DM2). MethodsData of NSCLC patients with DM2 who received treatment in six hospitals in China between January 2006 and January 2014 were reviewed retrospectively. They were divided into two groups: Group A, where the patients (n = 44) received EGFR-TKI plus metformin; and Group B, where the patients (n = 46) received EGFR-TKI plus hypoglycemic agents other than metformin. Prognostic differences between the two groups were assessed. ResultsThe median progression-free survival (PFS) and median overall survival (OS) in Group A were significantly longer than those in Group B (19.0 months vs. 8.0 months, P = .005; 32.0 months vs. 23.0 months, P = .002). The objective response rate (ORR) and disease control rate (DCR) in Group A were significantly higher than those in Group B (70.5% vs. 45.7%, P = .017; 97.7% vs. 80.4%, P = .009). Secondary data analysis showed that metformin use significantly prolonged the median PFS in subgroups using either first-line EGFR-TKI or second-line EGFR-TKI. ConclusionsMetformin and EGFR-TKI have a synergistic effect in the treatment of DM2 NSCLC patients harboring EGFR-activating mutations. Metformin use is associated with improved survival and delayed onset of acquired resistance to EGFR-TKI.

A Comparison of Effect of Metformin in Combination with Glimepiride and Glibenclamide on Glycaemic Control in Patients with Type 2 Diabetes Mellitus

A Comparison of Effect of Metformin in Combination with Glimepiride and Glibenclamide on Glycaemic Control in Patients with Type 2 Diabetes Mellitus

Abstract 1196: Enhancement of anti-melanoma effect of BRAF and MEK inhibition by metformin

Abstract Introduction: Metformin has been shown to inhibit human cancer cell growth via activation of MAP kinase with resultant inhibition of mTOR signaling pathway. Recent clinical evidence demonstrated the anti-melanoma effect of combined mutant BRAF inhibition and MEK inhibition. We determined the effect of metformin in combination with mutant BRAF and MEK inhibition on melanoma proliferation and the possible mechanisms. Methods: Human melanoma cells (SK-23, Mel888, Mel1861) were treated with Metformin (1-20 mM), PLX4032 (a mutant BRAF inhibitor, 1-20 uM), AZD6244 (a MEK inhibitor, 1-20 uM), or combination. Cell proliferation assay was performed using Cell Titer Blue assay. Western blotting was performed to determine the expression of PARP, caspases-9, LC3A/B,Beclin1, pERK, pMEK, AMPKa, p70S6, and p4E-BP1. GAPDH was used as internal control. Autophagy was further analyzed with immunofluorescence with LC-3 and NECN1 anti-antibody for visualization of lysosomal morphology and evaluated under the Nikon Eclipse Ti microscope (20×). DAPI was used to counter stain the nucleus. Apoptosis was further analyzed with flow cytometry using FITC Annexin V Apoptosis Detection Kit (BD Biosciences). Data were presented as means ± SD for the three separate experiments. For comparison between groups, the student's t test was used and p&amp;lt; 0.05 was considered to be statically significant. Results: There was dose-dependent inhibition of melanoma cell proliferation with either metformin(M), PLX4032(P), and AZD6244(A). Addition of M to PA combination had synergistic effect on the anti-melanoma proliferative effect of PA. Significantly increased expression (p&amp;lt;0.05) of apoptosis markers (PARP and caspases-9) and autophagy markers (LC3B and Beclin1) were observed in cells treated with PAM compared with PA. Enhanced induction of autophagy with the triple drugs was confirmed by visualization of autophagosome and autolysosome formation on immunofluorescence. Synergistic effect on apoptosis was confirmed on Annexin V assay. The PAM combination treatment also lead to significant enhancement of AMPK activation and increased phosphorylation of AMPKα at Thr-172 compared with metformin alone (p&amp;lt;0.01). The addition of M to PA combination resulted in inhibition of mTOR signaling with decreased phosphorylation of p70S6K and 4E-BP1 in treated cancer cells, when compared with PA or M alone. Conclusion: We have observed a synergistic effect on suppressing human melanoma proliferation with the addition of metformin to combined inhibition of mutant BRAF and MEK. The synergism is due to enhanced inhibition of mTOR signaling pathways. Citation Format: Yanping Zhang, Guangyong Peng, Eddy C. Hsueh. Enhancement of anti-melanoma effect of BRAF and MEK inhibition by metformin. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 1196. doi:10.1158/1538-7445.AM2015-1196

Abstract 1189: The impact of metformin on progression-free survival in patients with advanced pancreatic well differentiated neuroendocrine tumor receiving everolimus plus somatostatin analogue treatment

Abstract Introduction: Abnormal PI3K-Akt-mTOR pathway signaling and autocrine activation of the mTOR pathway, mediated through insulin-like growth factor 1 (IGF1), has been implicated in the proliferation of pNET cells. Everolimus (EVE), an inhibitor of mTOR (a central regulator of growth/proliferation, cellular metabolism and angiogenesis) has shown antitumor benefit in pNETs alone and in combination with Octreotide LAR (OCT) in RADIANT-1 and RADIANT-3 trials. An increasing number of studies have identified diabetic patients (pts) as having increased risk for the development of cancer and have associated Metformin (MET) treatment with a decrease of cancer risk. MET has also been associated with improved outcomes in cancer pts. MET has recently shown some anti-cancer activity, both in vitro and in vivo studies by antisecretory properties to decrease insulin and IGF1 levels and by antitumor effect due to AMPK activation and consequently inhibition to TSC1-2/mTOR complex, mediated to LKB1 oncogene expression. The aims of this retrospective study, even if in a limited number of pts is to evaluate the effect of concomitant MET administered during EVE plus OCT therapy in pts with pWDNETs and diabetes. Methods: We retrospectively evaluated the difference in terms of progression-free survival (PFS) between consecutive diabetic pts on MET and those on insulin (INS) as concomitant drugs during EVE plus OCT therapy. Normoglycemic pts served as controls. Results: Between 2009 and 2012, 31 pts (age 55.5 years; 22 males) were treated with EVE plus OCT. Six pts received MET, 6 received INS and 19 pts were normolgycemic. In the overall population, median PFS was 12 months (mo) (95%CI 6.3-17.7); mPFS was 24 mo (95% CI 8.6-59.9) in diabetic pts and 12 mo (95% CI 8.7- 15.3) in normoglycemic pts (HR 3.17, 95% CI 1.18-8.49; p = 0.016). Median PFS in pts on MET was “not achieved” versus 12.2 mo in pts treated with INS (95% CI 0-28). At the time of this analysis, 4 pts (67%) on MET are still receiving EVE plus OCT, with a median duration of treatment of 19.5 mo (range 10-27+ mo). Conclusion: Although the limited number of pts hampers the analysis, a prospective evaluation is required to either confirm or discard these preliminary findings. With the aim to evaluate the antiproliferative effect of MET in combination with EVE and OCT LAR in pWDNET pts, a single arm, prospective, single center phase II study was designed (MetNET-1 trial; NCT02294006). Forty-three patient will expect to be evaluated. The study is currently ongoing, and the recruitment is estimated to be completed in August 2016. The results will be anticipated in 2017. Citation Format: Sara Pusceddu, Roberto Buzzoni, Laura Concas, Cristina Bregant, Livia Leuzzi, Massimo Milione, Ettore Seregni, Barbara Formisano, Paola Consonni, Filippo De Braud. The impact of metformin on progression-free survival in patients with advanced pancreatic well differentiated neuroendocrine tumor receiving everolimus plus somatostatin analogue treatment. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 1189. doi:10.1158/1538-7445.AM2015-1189

Effects of Metformin on CD133+ Colorectal Cancer Cells in Diabetic Patients

In diabetic patients complicated with colorectal cancer (CRC), metformin treatment was reported to have diverse correlation with CRC-specific mortality. In laboratory studies, metformin was reported to affect the survival of cancer stem cells (CSCs) in breast and pancreatic cancers and glioblastoma. Although cscs play a critical role in the resistance to 5-fluorouracil (5-FU) chemotherapy in CRC patients, the effect of metformin on cscs in CRC patients and the synergistic effect of metformin in combination with 5-FU on cscs are not reported. In the present study pathological examinations were performed in 86 CRC patients complicated with type 2 DM who had been divided into a metformin group and a non-metformin group. Comparisons regarding pathological type, incidence of metastasis, expression of CD133 and β-catenin were conducted between the two groups. We explored the synergistic effects of metformin in combination with 5-FU on the proliferation, cell cycle, apoptosis and the proportion of CD133+ cscs of SW620 human colorectal cancer cell lines. The results show that metformin treatment had reverse correlations with the proportion of patients with poorly differentiated adenocarcinoma, the proportion of CD133+ cscs in CRC patients with type 2 DM. Metformin enhanced the antiproliferative effects of 5-FU on CD133+ cscs in SW620 cells. These findings provide an important complement to previous study. Inhibition of the proliferation of CD133+ cscs may be a potential mechanism responsible for the association of metformin use with improved CRC outcomes in CRC patients with type 2 diabetes.

Effect of metformin on residual cells after chemotherapy in a human lung adenocarcinoma cell line

Cancer chemotherapy, including molecular targeted therapy, has major limitations because it does not kill all the cancer cells; the residual cells survive until they acquire chemoresistance. In the present study, the combined effects of metformin and gefitinib were examined in vivo in a mouse xenograft model, inoculated with a human lung adenocarcinoma cell line that possesses an activating epidermal growth factor receptor mutation. The mechanism of the interaction was further elucidated in vitro. Metformin did not suppress the growth of already established tumors, nor did metformin augment tumor shrinkage by gefitinib. However, metformin significantly suppressed the regrowth of the tumor after effective treatment with gefitinib, suggesting the specific effect of metformin on the residual cells. Cytotoxicity of metformin was characterized by the absence of apoptosis induction and unremarkable cell cycle shift in vitro. The residual cell population after treatment with gefitinib was characterized by enriched cells with high expression of CD133 and CD24. Metformin was still effective on this specific cell population. Targeting residual cells after chemotherapy may represent an effective novel strategy for the treatment of cancer. Elucidating the mechanism of metformin cytotoxicity provides insights into future development of anticancer therapeutics.

The combined effect of metformin and l-cysteine on inflammation, oxidative stress and insulin resistance in streptozotocin-induced type 2 diabetes in rats

Increasing evidence has established causative links between obesity, chronic inflammation and insulin resistance; the core pathophysiological feature in type 2 diabetes mellitus. This study was designed to examine whether the combination of l-cysteine and metformin would provide additional benefits in reducing oxidative stress, inflammation and insulin resistance in streptozotocin-induced type 2 diabetes in rats. Male Wistar rats were fed a high-fat diet (HFD) for 8 weeks to induce insulin resistance after which they were rendered diabetic with low-dose streptozotocin. Diabetic rats were treated with metformin (300mg/kg/day), l-cysteine (300mg/kg/day) and their combination along with HFD for another 2 weeks. Control rats were fed normal rat chow throughout the experiment. At the end of treatment, fasting blood glucose, fasting serum insulin, homeostasis model assessment-insulin resistance index (HOMA-IR) and serum free fatty acids (FFAs) were measured. Serum levels of the inflammatory markers; monocyte chemoattractant protein-1 (MCP-1), C-reactive protein (CRP) and nitrite/nitrate were also determined. The liver was isolated and used for determination of malondialdehyde (MDA), reduced glutathione (GSH), caspase-3 and cytochrome c levels. The hypoglycemic effect of the combination therapy exceeded that of metformin and l-cysteine monotherapies with more improvement in insulin resistance. All treated groups exhibited significant reductions in serum FFAs, oxidative stress and inflammatory parameters, caspase-3 and cytochrome c levels compared to untreated diabetic rats with the highest improvement observed in the combination group. In conclusion, the present results clearly suggest that l-cysteine can be strongly considered as an adjunct to metformin in management of type 2 diabetes.

Preclinical model for combined effects of metformin and vitamin D3 on colitis-associated colon neoplasia.

e14634 Background: Metformin and vitamin D each has been shown to have anti-colon carcinogenic effects in pre-clinical and epidemiologic studies. We tested the potential synergistic effects of Metformin and vitamin D3 against colorectal neoplasia in a DMH-DSS induced colitis-associated colon neoplasia mouse model. Methods: We randomized 182 5-week old ICR male mice into 7 groups: 1) normal controls; 2) DMH controls; 3) DSS controls; 4) DMH + DSS controls; 5) vitamin D3 (3 dosage groups), 6) metformin (3 dosage groups), and 7) vitamin D3 + metformin (3 dosage combinations). After 20 weeks of treatment, the mice were sacrificed and colon tissues were harvested and examined for multiplicity of adenoma/cancer, volume of each tumor, number and score of aberrant crypt foci (ACF). Results: Compared to the DMH + DDS controls, combination of vitamin D3 (200 IU/kg/day) and metformin (240 mg/kg/day) statistically significantly reduced the average number of adenoma/cancer per mouse formed (6.20 ± 3.68 vs. 2.20 ± 2.12, p&lt;0.01), volume (mm3 ) of tumor (115.46 ± 107.32 vs. 31.05 ± 38.26, p&lt; 0.05), number of ACF (0.46 ± 0.88 vs. 2.58 ± 1.93, p &lt;0.01), and ACF score (5.00 ± 3.26 vs. 1.23 ± 2.04, p &lt;0.01). Western blot and IHC show that vitamin D3 potentiates metformin in activating AMPK (phos-AMPK: 0.53 ± 0.01 vs. 0.70 ± 0.03, p &lt; 0.01), inhibiting AKT (phos-AKT: 0.39 ± 0.10 vs. 0.15 ± 0.04, p &lt; 0.01), S6P (phos-S6P: 0.36 ± 0.03 vs. 0.14 ± 0.04, p &lt;0.01), cyclin D1 (0.24 ± 0.02 vs. 0.06 ± 0.02, p &lt;0.01), ?-catenin (0.808 ± 0.142 vs. 0.010 ± 0.001, p &lt; 0.01), and VDR (0.182 ± 0.045 vs. 0.488 ± 0.081). Combination treatment also statistically significantly increases serum levels of IGFBP-3, with little effect on IGF-1, IGFBP-1 or IL-1?. Conclusions: Metformin and vitamin D3 synergistically inhibit the development of colorectal neoplasia in a colitis-associated mouse colon carcinogenesis model. Further study of the underlying mechanisms is warranted.

EFFECT OF INTERACTION BETWEEN METFORMIN AND GLIMIPERIDE ON GLYCOSYLATED HAEMOGLOBIN AND LIPID PROFILE IN STRESS INDUCED TYPE 2 DM

The aim of the present study is to evalutae the effect of metformin in combination with Glimepiride and in patient with type 2 Diabetes Mellitus.The research is carried out to  study the effect of metformin when it is given in combination on glycaemic control in patient with type 2 Diabetes Mellitus. Patients with Glycosylated Hemoglobin more than 6.5% were included in the study. 30 animal in five group were randomly assigned for treatment based on metformin and glimepiride in a dose of 200 mg/kg and 17.5 mg/kg for 21 weeks. The comparisons were conducted between these five groups for HbA1C, FPG, PPG and lipid profile. On week 21, the significant reductions in HbA1c were found in drug treated groups but the patients treated with metformin and glimepiride resulted in significantly greater reductions in HbA1C  . Also the greater significant reductions were observed in case of FPG, total cholesterol, serum triglyceride and LDL cholesterol in patient with metformin and glimepiride treated group.  Key word-Metformin,glimiperide,Diabetes,hypoglycemic agent,safety

Abstract 5402: Synergism of Metformin and DFMO on colon cancer proliferation and migration.

Abstract Introduction: Metformin has been shown to inhibit cancer cell growth via activation of MAP kinase with resultant inhibition of mTOR signaling pathway. ODC, a key enzyme in polyamine biosynthesis, was found to be overexpressed in colon cancer. We determined the effect of metformin in combination with DMFO, an ODC inhibitor, on tumor proliferation and migration in human colon cancer cells. Methods: Human colon cancer cells, HCT 116 and HT 29, were treated with Metformin, DFMO, or combination. Cell proliferation assay was performed using Cell Titer Blue proliferation assay. Cell migration assay was performed by seeding colon cancer cells in 24-well plate. After overnight incubation, an artificial homogenous wound was created onto the monolayer with a plastic micropipette tip. After wounding, the migration of cells into the wound was observed up to 72 hours at various time points. Quantitative RT-PCR for ODC1 detection was performed using Assay-on-Demand Hs00159739-ml. GAPDH served as control. Western blotting was performed to determine the expression of AMP kinase, mTOR, p70S6K and 4E-BP1. Data were presented as means ± SD for the three separate experiments. For comparison between groups, the student's t test was used and p&amp;lt; 0.05 was considered to be statically significant. Results: There was dose-dependent (1-10 mM for DFMO and 1-20 mM for metformin) time-dependent (up to 96 hours) inhibition of cell proliferation and migration with either metformin or DFMO in both HCT 116 and HT 29 cells. Synergistic inhibition was observed with the combination treatment (5 mM DFMO and 5 mM Metformin) on both cell migration and proliferation at 24 hours compared with either agent alone. There was synergistic inhibition of ODC expression with the combined treatment compared with DFMO alone at 24 hours (p&amp;lt;0.01). The combination treatment also lead to significant enhancement of AMPK activation and increased phosphorylation of AMPKα at Thr-172 compared with metformin alone (p&amp;lt;0.01). The combination treatment resulted in significant inhibition of mTOR signaling with decreased phosphorylation of mTOR, p70S6K and 4E-BP1 in treated cancer cells, when compared with individual drug treatments. Inhibition of proliferation and migration was significantly greater in the mismatch-repair defective HCT 116 cells than HT 29. Conclusion: We have observed a synergistic effect of metformin and DFMO in suppressing human colon cancer proliferation and migration. The synergism reflects enhanced inhibition of both polyamine synthesis and mTOR signaling pathways by the drug combination. Citation Format: Yanping Zhang, Luz M. Rodriguez, Ronald Lubet, Eddy C. Hsueh. Synergism of Metformin and DFMO on colon cancer proliferation and migration. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 5402. doi:10.1158/1538-7445.AM2013-5402