Potential Of Metformin Research Articles

Anticancer role of antidiabetic drug Metformin in ovarian cancer cells

Purpose: Epithelial ovarian cancer is the most common ovarian cancer and has life threatening implications. Despite the progress in surgical and therapeutic strategies, resistance to chemotherapy is still a major concern. Chemotherapeutic agents cause cytotoxicity, primarily by the induction of apoptosis. The status of p53 is a key factor in determining the efficacy of apoptotic signaling. p53 is the most commonly mutated tumor suppressor gene in ovarian cancer. Metformin (an antidiabetic drug) has shown putative effects in many solid tumors. Hence we aimed to study the role of metformin in p53 mutated cancer cells. Methods: SKOV3 and OAW42 ovarian cancer cell line were used. The cancer cells were treated with metformin. MTT, Flow cytometry and Western blotting were used to characterize the effects of the different treatments. Results: Metformin treatment leads to cell cycle arrest in the G0/G1, S and G2/M phase of the cell cycle in SKOV3 and OAW42 respectively. Moreover, there was upregulation of Bax and downregulation of Bcl-2 protein and increased apoptosis in SKOV3 and OAW42 ovarian cancer cells. Conclusion: These findings support the potential of metformin to be used as chemoadjuvant and reflects its ability to sensitize cancer cells to apoptosis independent of p53 status.

Metformin Prevents Dopaminergic Neuron Death in MPTP/P-Induced Mouse Model of Parkinson’s Disease via Autophagy and Mitochondrial ROS Clearance

Background:Our previous study demonstrated that metabolic inflammation exacerbates dopaminergic neuronal degeneration in type 2 diabetes mice. Metformin, a typical oral hypoglycemic agent for diabetes, has been regarded as an activator of AMP-activated protein kinase and a regulator of systemic energy metabolism. Although metformin plays potential protective effects in many disorders, it is unclear whether metformin has a therapeutic role in dopaminergic neuron degeneration in Parkinson’s disease.Methods:In the present study, a 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine plus probenecid-induced mouse model of Parkinson’s disease was established to explore the neuroprotective effect of metformin on dopaminergic neurons in substania nigra compacta. We next cultured SH-SY5Y cells to investigate the mechanisms for the neuroprotective effect of metformin.Results:We showed that treatment with metformin (5mg/mL in drinking water) for 5 weeks significantly ameliorated the degeneration of substania nigra compacta dopaminergic neurons, increased striatal dopaminergic levels, and improved motor impairment induced by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine plus probenecid. We further found that metformin inhibited microglia overactivation-induced neuroinflammation in substania nigra compacta of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine plus probenecid Parkinson’s disease mice, which might contribute to the protective effect of metformin on neurodegeneration. Furthermore, metformin (2mM) activated AMP-activated protein kinase in SH-SY5Y cells, in turn inducing microtubule-associated protein 1 light chain 3-II-mediated autophagy and eliminating mitochondrial reactive oxygen species. Consequently, metformin alleviated MPP+-induced cytotoxicity and attenuated neuronal apoptosis.Conclusions:Our findings demonstrate that metformin may be a pluripotent and promising drug for dopaminergic neuron degeneration, which will give us insight into the potential of metformin in terms of opening up novel therapeutic avenues for Parkinson’s disease.

An integrative cross-tumors approach identifies FOSL1 as an oncogene dependency in KRAS-driven lung cancer

The Ontario Clinical Oncology Group (OCOG) – ALMERA trial (NCT02186847) is a Canadian multicenter randomized phase II trial funded by the Canadian Institute for Health Research, which is designed to examine whether metformin has chemo-radio-sensitization activity as well as activity as a single agent in advanced localized NSCLC. A total of 94 patients will be randomized in this screening trial to standard CRT with or without treatment with 2000mg of metformin, which is delivered during CRT (2 cycles of cisplatin based chemotherapy, concurrent with chest RT of 63 Gy in 30 fractions) but continues also as a single agent for a total of 12 months. ALMERA is designed to detect a 20% improvement in lung cancer progression free survival at 12 months. This trial is now open in several centers across Canada. The primary outcome is 12 month Progression Free Survival (PFS) and secondary outcomes include 1 and 2 y overall survival (OAS), time to loco-regional progression, distant progression free survival, adverse events and collection of biospecimens for biomarker studies. These will involve investigation of circulating serum and blood cell biomarkers of metformin activity and tumor biomarkers such as tumor histology, TP53, LKB1 and K-Rasmutation status. When completed ALMERAwill provide some of the first prospective evidence on the potential of metformin to improve the outcomes of standard cytotoxic therapy in locally advanced NSCLC. Biospecimen collect will allow us to investigate serum and tumors biomarkers ofmetformin response. Comparison of the results of ALMERA with other studies, like NRG-LU001, may be able to provide evidence on the value of metformin as maintenance therapy and assist in the design of future phase III trials with metformin in the setting of locally advanced NSCLC.

Clinical and radiographic evaluation of the influence of antihyperglycemic drug (metformin) on healing of bone and periodontal defects after impacted mandibular third molar surgery

Objectives The purpose of the current study was to clinically and radiographically assess the regenerative potential of metformin in enhancement of bone healing in third molar extraction sites. Patients and methods The present study included 40 healthy volunteers (27 females and 13 males) aged 21-27 years who had been scheduled for surgical removal of their impacted mandibular third molars. Volunteers were randomly assigned to either groups A or B. Twenty patients of group A (test) underwent surgical removal of impacted mandibular third molar followed by application of metformin gel in the surgical site. Twenty patients of group B (control) underwent surgical removal of impacted mandibular third molar only. Clinical and radiographic evaluation (cone beam computed tomography) was performed immediately after operation and at 6 months postoperatively in terms of the probing pocket depth, the bone defect length at the distal side of second lower molars, and bone density. Data were collected and statistical analysis was performed. Results At 6 months postoperatively group A (test) showed significantly higher (P ≤ 0.001) mean bone density compared with group B (control). On the other hand, there was nonsignificant (P ≥ 0.001) difference in the periodontal pocket depth and defect length between the test and control groups after 6 months. Conclusion There was a significant improvement regarding bone density at the surgical site using metformin after impacted mandibular third molar removal. Thus bone-formative effects of the common oral antihyperglycemic agent MF can provide a new direction in the field of bone healing.

Abstract A23: Cancer outcomes in the diabetes prevention program outcomes study

Abstract Numerous observational studies have reported decreased cancer incidence and cancer-related mortality in patients with diabetes receiving standard doses of metformin. A recent meta-analysis of these studies suggested a 31% reduction in overall cancer incidence, summary relative risk (0.69; 95% confidence interval, 0.52-0.90), in subjects taking metformin as compared with other antidiabetic drugs. Separate meta-analyses of studies that adjusted for BMI or time-related bias suggested an attenuation of this signal, but still showed a significant reduction in cancer incidence. However, studies published to date are limited by the observational nature of the data and the randomized controlled trials that have been used to examine metformin's potential as an anti-cancer agent in patients with diabetes have had insufficient follow-up for cancer endpoints. These data also do not address the cancer risk in non-diabetic populations, in which the cancer preventive potential of metformin is unknown. The Diabetes Prevention Program (DPP) was a national multi-center, randomized, placebo-controlled clinical trial, which enrolled 3234 participants between 1996 and 1999, designed to investigate whether intensive lifestyle modification or treatment with metformin (850mg twice a day) delayed or prevented the onset of type 2 diabetes in a high risk population. The DPP and its follow up study, the Diabetes Prevention Program Outcomes Study (DPPOS), provide a unique opportunity to examine the role of metformin and lifestyle intervention in reducing cancer incidence in an overweight adult population with impaired glucose regulation, before the onset of diabetes. The National Cancer Institute Division of Cancer Prevention, in collaboration with the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) and the DPPOS investigators, proposed a study to examine the hypothesis that metformin and/or lifestyle intervention can modify total cancer incidence and/or obesity-related cancer incidence (breast, colorectal, endometrium, pancreas, lower esophagus, gall-bladder, and kidney) in DPP/DPPOS participants. The DPPOS protocol and consent were modified to allow collection of data to support the inclusion of cancer incidence as an endpoint of interest in the study. Participants complete a cancer risk questionnaire that includes family history of cancer, cancer screening activities, and use of aspirin and NSAIDs including dose and frequency. The participants who previously reported a cancer diagnosis, through the SAE reporting process and/or an annual questionnaire, or during a subsequent follow-up visit, are asked to provide physician information to obtain medical records for case adjudication. This protocol will allow for the examination of the effect of metformin and lifestyle intervention on cancer incidence in an initially pre-diabetic population potentially through a median of 20 years of follow-up. Data from this study will compare incidence of total and obesity-related cancers between the original treatment groups; assess cancer (total and obesity-related) incidence by metformin exposure across all treatment groups, using a “met-years” variable, and explore subgroups to investigate effect modification by sex, age group, race/ethnicity, diabetes status, or weight loss at 1 year or mean weight loss since study baseline. Citation Format: Brandy M. Heckman-Stoddard, Jill P. Crandall, Sharon L. Edelstein, Richard F. Hamman, Philip C. Prorok, Anne Ryan, Dana Dabelea, Helen P. Hazuda, Edward Horton, Mary A. Hoskin, Susan Jeffries, William C. Knowler, Kieren J. Mather, Susana M. Shapiro, Farzana L. Walcott, Leslie G. Ford. Cancer outcomes in the diabetes prevention program outcomes study. [abstract]. In: Proceedings of the Thirteenth Annual AACR International Conference on Frontiers in Cancer Prevention Research; 2014 Sep 27-Oct 1; New Orleans, LA. Philadelphia (PA): AACR; Can Prev Res 2015;8(10 Suppl): Abstract nr A23.

Activity and Safety of Everolimus in Combination with Octreotide Lar and Metformin in Patients with Advanced Pancreatic Well-Differentiated Neuroendocrine Tumors (Pwdnets): a Single–Center, Open-Label, Phase Ii, Proof-Of-Concept Study (Metnet1 Trial)

ABSTRACT Background: 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 mTOR inhibitor (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 studies. Despite EVE-based phase II/III trials improve progression-free survival (PFS) for pNETs, they are limited to significantly prolong overall survival (OS). Metformin (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. Our retrospective experience, despite in a limited group of pWDNET, highlights the role of MET to improve clinical benefit in diabetic pts receving EVE-OCT combination. Trial design: Pts with advanced pWDNET, will receive a combination of EVE 10 mg/daily, OCT LAR 30 mg/month and MET 2000 mg/daily, until progression or inacceptable toxicity. Tumor radiological progression will be assessed every 4 months (mo). The primary objective is to evaluate the activity of EVE-OCT combination with MET in advanced pWDNETs through PFS rate, according to RECIST criteria. Based on RADIANT-3 results, with a PFS rate equal to 47% in 12 mo under the null hypothesis, the aim is to evaluate an increase of 20%. Secondary objective include safety, overall response rate (RR), OS, biomarkers RR defined as the impact of study treatment on circulating plasma Cromogranine A, IL6, and IGF1 levels. For a single-stage design, chosen a = 0.10 one-tailed and b = 0.10 (90% power), 43 pts will be enrolled. In April 2014 the trial received institutional ethic board approval and in June 2014 the enrollment was start. Recruitment is expected to be completed in July 2016. Study results will be anticipated in 2017. This study will investigate the antiproliferative potential of MET in combination with EVE and OCT in pWDNETs. MetNET1 prospective trial (EudraCT 2014-000888-41) may be helpful to either confirm or discard these preliminary findings. Disclosure: All authors have declared no conflicts of interest.

Metformin inhibits urothelial tumorigenesis in the UPII-mutant Ha-ras transgenic mouse model

Background Bladder cancer occurs mainly in older people and is expensive to manage. As the population continues to age, bladder cancer may remain to be a major public health burden. Therefore, we hypothesized that an agent, like metformin, with anti-aging property could have preventive activity against the development and progression of human urinary bladder cancer. Materials and methods The UPII mutant Ha-ras transgenic mouse model mimics human papillary transitional urothelial cell carcinoma and exhibits enhanced mTOR activity in tumor tissues. Homozygous UPII mutant Ha-ras transgenic mice were identified through genotyping using the Southern blotting method. Genotyped Ha-ras mice were then fed orally with normal drinking water or 0.1% or 0.05% metformin in drinking water starting at 6 weeks of age and ending at 6 months of age. Death rate, body weight, tumor burden, and proliferative and apoptotic indices at the end of treatments will be evaluated by pathological and statistical analyses. Results About 62% of male, homozygous mutant Ha-ras transgenic mice which drank normal water died of urinary tract obstruction and hydronephrosis within 6 months of age, while only about 11% or 15% of mice which drank 0.1% or 0.05% metformin containing water died. Drinking metformin dramatically increased the survival of mutant Ha-ras tumor bearing mice by 51 to 47% (Ps<0.01). Metformin drinking also significantly decreased the mean bladder weights of male, homozygous mutant Ha-ras transgenic mice by up to 62%. Histological analysis of H&E stained bladder sections from metformin treated mice demonstrated more differentiated tumors compared to those in control groups. The in vivo mechanisms of metformin’s action are associated with anti-proliferation, reduction of phospho-mTOR and 4E-BP1 expression and induction of TSC2 expression in bladder tissues. Conclusions Our results demonstrated strong in vivo anti-urothelial tumorigenesis activity of metformin drinking in the UPIImutant H-ras model via inhibition of the mTOR pathway. These results suggested the potential of metformin in preventing recurrence of clinical bladder cancer and in improving quality of life for patients.

Prognostic Significance of AMPK Activation and Therapeutic Effects of Metformin in Hepatocellular Carcinoma

The AMP-activated protein kinase (AMPK) serves as an energy sensor in eukaryotic cells and occupies a central role in linking metabolism and cancer development. However, the phosphorylation status of AMPK and its therapeutic value in human hepatocellular carcinoma (HCC) remain unclear. The phosphorylation status of AMPK (Thr172) was determined by immunoblotting and immunostaining in specimens from 273 patients with HCC (including 253 patients with hepatitis B virus -related HCC). Kaplan-Meier survival analysis was used to determine the correlation with prognosis. The effects of therapeutic metformin/AMPK activation were assessed in cultured human HCC cell lines and primary HCC cells in vitro and in xenograft tumors model in vivo. To define the mechanisms of anticancer effects of metformin, we examined its influence on AMPK activation and NF-κB pathway. AMPK is dysfunctional in patients with HCC, and low p-AMPK staining is correlated with aggressive clinicopathologic features and poor prognosis. Activation of AMPK by metformin not only inhibited HCC cells growth in vitro and in vivo, but also augmented cisplatin-induced growth inhibition in HCC cells. Knockdown of AMPKα expression can greatly decrease the inhibitory effect of metformin, indicating that AMPK activation is required for the anticancer action of metformin. Mechanistically, metformin/AMPK activation inhibited NF-κB signaling through upregulation of IκBα. Activation of NF-κB signaling by ectopic expression of P65 or overexpression of an undegradable mutant form of IκBα attenuated the anticancer effects of metformin. These results present novel insight into a critical role of AMPK in HCC progression. Anticancer effects of therapeutic metformin/AMPK activation unravel metformin's potential in treatment of HCC.

Metformin-induced diarrhea as delayed adverse reaction after many years of use: Case report

Background : Metformin is an oral antidiabetic drug from bigvanides group. It does not cause hypoglycemia, and therefore has found its place as a first-line therapy in type 2 diabetes. It is used both as mono-therapy and as adjunctive therapy with other anti-diabetics and insulin. Some of the most common adverse reactions of metformin are: gastrointestinal upset, diarrhea, nausea, flatulence and vomiting. Adverse reactions usually occur at the beginning of the therapy. Aim : To show the potential of metformin to cause delayed adverse effects after years of use. Case report : A sixty-four-year-old woman with type 2 diabetes was treated with metformin for ten years. Several months ago she started to have diarrhea with fluctuating character and intensity. She lost 20 pounds in weight without a special diet. Gastroenterologist and surgeon were consulted, but the cause of diarrhea was not established. A clinical pharmacologist was consulted next to evaluate possible relationship between diarrhea and medication. According to the relevant literature, metformin had the highest prevalence of diarrhea among the medication that was taken by the patient. Therefore, the strategy of discontinuation and then re-challenge by the drug was used. Two days after the metformin was discontinued the diarrhea stopped, and five days later, after the patient was re-challenged by the drug, diarrhea reappeared, with similar characteristics as before. Conclusion: Metformin-induced diarrhea usually occurs at the beginning of the treatment. However, it could have delayed appearance, even after many years of continuous use of metformin.

Abstract 2491: Metformin sensitizes human lung cancer xenografts to ionizing radiation: Response of the AMPK pathway

Abstract Introduction : Radiation therapy is a standard therapeutic modality in lung cancer (LC). Unfortunately, LC demonstrates radiation resistance and poor response to even high doses of chest radiotherapy. Therefore, there is an urgent need to develop effective and well tolerated radiation sensitizers in LC. Recently, we showed that ionizing radiation (IR) and metformin (MET) activate the energy sensor and tumor suppressor kinase AMP-activated kinase (AMPK). MET enhanced IR activation of AMPK in LC cells and increased the cytotoxicity of IR in clonogenic assays. In the present study we investigated, in human LC xenografts, the radio-sensitizing properties of MET and its effects on the activity of the AMPK pathway in intact tumors. Methods: A549 cells (2×106) were grafted in the franks of Balb/c immunodeficient athymic nude mice and tumors were left to grow to 100 mm3. MET supplementation was delivered in drinking water at a dose of 250 mg/kg daily, and IR of 10 Gy was delivered as a single fraction 7 days after initiation of metformin administration. Eight weeks later animals were euthanized and tumors where isolated. Half of each tumor was snap frozen for preparation of whole tumor lysates and immunoblotting analysis and the other half was fixed and embedded for immunohistochemistry analysis. Tumour growth kinetics and levels of total AMPK, phosphor (P)-AMPK (P-AMPK Thr172) and P-Acetyl-CoA Carboxylase (ACC) and P-Akt were evaluated. Results: MET and IR alone inhibited significantly A549 LC xenograft tumor growth. Furthermore, the combined treatment of MET and IR produce an additive effect and inhibited tumor growth more than each treatment alone. Both IR and MET enhanced AMPK phosphorylation and activity detected by ACC phosphorylation. Similar to tumor growth kinetics, the combined treatment of MET+IR enhanced AMPK activity and phosphorylation above the levels of each treatment alone. However, we also detected that MET and IR treatments also increased significantly the total AMPK α subunit levels in tumor tissues with a consistent potentiation of this effect when the two treatments were combined. On the other hand MET showed a tendency to inhibit basal and radiation-induced Akt phosphorylation levels in xenografts. Our immunoblotting results were verified with immunohistochemistry experiments. Conclusion: Similar to our earlier observations in tissue culture models, the present studies suggest that MET inhibits LC tumour growth and sensitizes them to IR. The two agents mediate both expression and activation of AMPK which appears to be associated with inhibition of Akt. Activation of AMPK by MET and IR in-vivo does not appear to depend on LKB1 as A549 cells are LKB1 null. These results demonstrate the potential of MET to function as a radiation sensitizer in-vivo and support evaluation of this drug in LC clinical trials in combination with radiation. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 2491. doi:10.1158/1538-7445.AM2011-2491

Utilizing metformin as a radiosensitizing agent in the treatment of prostate cancer.

89 Background: External beam radiation therapy (EBRT) is a well recognized curative prostate cancer (PCa) treatment modality utilizing ionizing radiation (IR). In addition to mediating DNA damage, IR upregulates several intracellular pro-survival pathways including the insulin- like growth factor (IGR) signaling network. This may contribute to the intrinsic radioresistance exhibited by certain tumors. Diabetic patients with PCa experience poorer outcomes following EBRT than their non-diabetic counterparts. Some attribute this to diabetes-induced chronic hyperinsulinemia with consequent upregulation of pro-survival insulin/IGF signalling. Previous work by our group showed diet-induced hyperinsulinemia to enhance PCa tumor growth in vivo. Metformin, a diabetic treatment, alleviates hyperinsulinemia, and also exhibits anti-neoplastic properties. We postulate that pre-treatment with metformin to correct hyperinsulinemia may protect cells from radiation-mediated pro-survival insulin/IGF signaling. Thus we assessed the radiosensitizing potential of metformin using in vitro and in vivo PCa models. Methods: The effect of IR and/or metformin on colony formation rates was assessed in LNCaP, PC3, DU145 and PC3AR2 PCa cell lines using clonogenic assay. The combination treatment regimen was assessed in vivo using a murine xenograft model. Western blot and cell cycle analyses are ongoing to try and elucidate any mechanisms of interaction between metformin and IR. Results: Monotherapy with IR (1-8Gy) or metformin (0.01-10.0mM) caused significant dose-dependent reduction in colony formation rates (p&lt;0.001). Combination treatment further significantly reduced colony formation rates (p&lt;0.03). Preliminary results from our in vivo study show diminished tumor growth in response to combination treatment (p&lt;0.0001), and are currently subject to ongoing statistical analyses. Conclusions: Our in vitro findings confirm combining metformin with IR significantly reduces PCa cell colony formation rates further than either monotherapy. Recapitulation of these results in vivo would provide justification for translating this work into a phase II clinical trial of metformin as a radiosensitizing agent. No significant financial relationships to disclose.

Metformin and cancer: licence to heal?

Type 2 diabetes mellitus is associated with increased risk of malignancy (mainly cancer of the pancreas, breast, colon, endometrium and bladder). In addition, there is evidence that antidiabetic medication may itself affect the risk of cancer. Importantly, metformin is nowadays emerging as an agent that has the potential to protect from cancer. Population studies have shown that metformin is associated with a significant reduction of neoplasias in general (and cancer of the breast and prostate, in particular). These observations are supported by in vitro and in vivo evidence that metformin inhibits the growth of cancer cells. The mechanisms underlying this protective potential of metformin are not completely understood. While other mechanisms have also been proposed, the protective action of metformin appears to be exerted by two main pathways. The first involves reduction of endogenous hyperinsulinemia. The second pathway relates to the activation of adenosine monophosphate-activated protein kinase (AMPK), which is recognized to inhibit cellular protein synthesis and growth. Whatever the precise mechanism, any reduction in the risk for cancer may be far-reaching, and this favorable effect adds to the clinical value of metformin as the mainstay of antidiabetic treatment.

Metformin for prevention of type 2 diabetes.

To evaluate evidence from the medical literature that metformin is effective in preventing type 2 diabetes. Primary literature was accessed via a MEDLINE search (1966-December 2003) using the terms metformin, type 2 diabetes, and prevention. Two studies evaluated metformin's potential to prevent type 2 diabetes, finding that metformin maintained or reduced fasting blood glucose in non-diabetics. Recently, a large study by the Diabetes Prevention Program showed that metformin may reduce the incidence of diabetes. Researchers compared lifestyle changes, metformin therapy, and placebo groups. They found that both lifestyle changes (58%) and metformin therapy (31%) significantly reduced the occurrence of type 2 diabetes versus placebo. These studies provide evidence that metformin may reduce the occurrence of type 2 diabetes. Because long-term efficacy has not been determined, further studies are needed.