Diabetes and cancer

Engineered Glucose Oxidase-Carbon Nanotube Conjugates for Tissue-Translatable Glucose Nanosensors

Continuous and non-invasive glucose monitoring and imaging is important for disease diagnosis, treatment, and management. However, glucose monitoring remains a technical challenge owing to the dearth of tissue-transparent glucose sensors. In this study, we present the development of near-infrared fluorescent single-walled carbon nanotube (SWCNT) based nanosensors directly functionalized with glucose oxidase (GOx) capable of immediate and reversible glucose imaging in biological fluids and tissues. We prepared GOx-SWCNT nanosensors by facile sonication of SWCNT with GOx in a manner that-surprisingly-does not compromise the ability of GOx to detect glucose. Importantly, we find by using denatured GOx that the fluorescence modulation of GOx-SWCNT is not associated with the catalytic oxidation of glucose but rather triggered by glucose-GOx binding. Leveraging the unique response mechanism of GOx-SWCNT nanosensors, we developed catalytically inactive apo-GOx-SWCNT that enables both sensitive and reversible glucose imaging, exhibiting a ΔF/F0 of up to 40 % within 1 s of exposure to glucose without consuming the glucose analyte. We finally demonstrate the potential applicability of apo-GOx-SWCNT in biomedical applications by glucose quantification in human plasma and glucose imaging in mouse brain slices.

Deglycation activity of the Escherichia coli glycolytic enzyme phosphoglucose isomerase

Glycation is a spontaneous chemical reaction, which affects the structure and function of proteins under normal physiological conditions. Therefore, organisms have evolved diverse mechanisms to combat glycation. In this study, we show that the Escherichia coli glycolytic enzyme phosphoglucose isomerase (Pgi) exhibits deglycation activity. We found that E. coli Pgi catalyzes the breakdown of glucose 6-phosphate (G6P)-derived Amadori products (APs) in chicken lysozyme. The affinity of Pgi to the glycated lysozyme (Km, 1.1 mM) was ten times lower than the affinity to its native substrate, fructose 6-phosphate (Km, 0.1 mM). However, the high kinetic constants of the enzyme with the glycated lysozyme (kcat, 396 s-1 and kcat/Km, 3.6 × 105 M-1 s-1) indicated that the Pgi amadoriase activity may have physiological implications. Indeed, when using total E. coli protein (20 mg/mL) as a substrate in the deglycation reaction, we observed a release of G6P from the bacterial protein at a Pgi specific activity of 33 μmol/min/mg. Further, we detected 11.4 % lower APs concentration in protein extracts from Pgi-proficient vs. deficient cells (p = 0.0006) under conditions where the G6P concentration in Pgi-proficient cells was four times higher than in Pgi-deficient cells (p = 0.0001). Altogether, these data point to physiological relevance of the Pgi deglycation activity.

Diabetes and ovarian cancer: risk factors, molecular mechanisms and impact on prognosis

BACKGROUND AND AIM

Diabetes mellitus has been linked to a lower rate of cancer survival and an increase in the incidence of most malignancies. Investigations showed that diabetes might affect ovarian cancer (OC) prognosis and survival. Based on the current information, this study intends to review the risk factors, molecular pathways, and impact of diabetes on OC.

METHODS

The data was derived from online databases, including Web of Science, PubMed, and Scopus. The inclusion criteria were original studies, which included the risk factors, molecular mechanisms, and impact of diabetes on OC. The effect of different antidiabetic drugs was also discussed in this manuscript. All of the clinical, in vivo, and in vitro studies were included in the present study.

RESULTS

The diagnosis of diabetes mellitus negatively affects the survival and prognosis in OC cases. The epidemiologic data shows that the risk of OC increases in patients with diabetes mellitus compared to the healthy population. Insulin-like growth factors family was raised in diabetic patients, which target several mechanisms, including targeting oxidative stress, angiogenesis, and tumor markers. Antidiabetic drugs such as metformin, sitagliptin, and rosiglitazone have a promising effect on elongation of survival and enhancement of prognosis in OC patients.

CONCLUSIONS

Diabetes mellitus is a significant risk factor for OC in women, and it negatively impacts survival and prognosis. Molecular mechanisms such as IGF family, oxidative stress, and inflammatory cytokines have been identified to explain this relationship. Antidiabetic drugs like metformin, sitagliptin, and rosiglitazone have shown promise in improving survival and prognosis of OC patients.

Assessing the Effect of Cancer Diagnosis on Beliefs about Comorbid Diabetes

OBJECTIVES

Increasingly, patients diagnosed with cancer also live with chronic comorbidities, and it is important to understand the impact of a new cancer diagnosis on perceptions about preexisting conditions. This study assessed the effect of cancer diagnosis on beliefs about comorbid diabetes mellitus and assessed changes in beliefs about cancer and diabetes over time.

DATA SOURCES

We recruited 75 patients with type 2 diabetes who were newly diagnosed with early-stage breast, prostate, lung, or colorectal cancer and 104 age-, sex-, and hemoglobin A1c-matched controls. Participants completed the Brief Illness Perception Questionnaire four times over 12 months. The authors examined within-patient and between-group differences in cancer and diabetes beliefs at baseline and over time.

RESULTS

Overall, diabetes beliefs did not differ between cancer patients and controls at baseline. Cancer patients' beliefs about diabetes varied significantly over time; they reported less concern about cancer, less emotional effect, and greater cancer knowledge over time. Participants without cancer were significantly more likely to report that diabetes affected their life across all time points, though this effect did not persist after adjustment for sociodemographic variables.

CONCLUSION

While all patients' diabetes beliefs were similar at baseline and 12 months, cancer patients' beliefs about both illnesses fluctuated during the months following cancer diagnosis.

IMPLICATIONS FOR NURSING PRACTICE

Oncology nurses can play a key role in recognizing the effects of cancer diagnosis on beliefs about comorbid conditions and fluctuations in these beliefs during treatment. Assessing and communicating patient beliefs between oncology and other practitioners could produce more effective care plans based on patients' current outlook on their health.

Glycation Interferes with the Expression of Sialyltransferases in Meningiomas

Meningiomas are the most common non-malignant intracranial tumors and prefer, like most tumors, anaerobic glycolysis for energy production (Warburg effect). This anaerobic glycolysis leads to an increased synthesis of the metabolite methylglyoxal (MGO) or glyoxal (GO), which is known to react with amino groups of proteins. This reaction is called glycation, thereby building advanced glycation end products (AGEs). In this study, we investigated the influence of glycation on sialylation in two meningioma cell lines, representing the WHO grade I (BEN-MEN-1) and the WHO grade III (IOMM-Lee). In the benign meningioma cell line, glycation led to differences in expression of sialyltransferases (ST3GAL1/2/3/5/6, ST6GAL1/2, ST6GALNAC2/6, and ST8SIA1/2), which are known to play a role in tumor progression. We could show that glycation of BEN-MEN-1 cells led to decreased expression of ST3Gal5. This resulted in decreased synthesis of the ganglioside GM3, the product of ST3Gal5. In the malignant meningioma cell line, we observed changes in expression of sialyltransferases (ST3GAL1/2/3, ST6GALNAC5, and ST8SIA1) after glycation, which correlates with less aggressive behavior.

Hyperglycemic conditions proliferate triple negative breast cancer cells: role of ornithine decarboxylase

PURPOSE

Several cancer subtypes (pancreatic, breast, liver, and colorectal) rapidly advance to higher aggressive stages in diabetes. Though hyperglycemia has been considered as a fuel for growth of cancer cells, pathways leading to this condition are still under investigation. Cellular polyamines can modulate normal and cancer cell growth, and inhibitors of polyamine synthesis have been approved for treating colon cancer, however the role of polyamines in diabetes-mediated cancer advancement is unclear as yet. We hypothesized that polyamine metabolic pathway is involved with increased proliferation of breast cancer cells under high glucose (HG) conditions.

METHODS

Studies were performed with varying concentrations of glucose (5-25 mM) exposure in invasive, triple negative breast cancer cells, MDA-MB-231; non-invasive, estrogen/progesterone receptor positive breast cancer cells, MCF-7; and non-tumorigenic mammary epithelial cells, MCF-10A.

RESULTS

There was a significant increase in proliferation with HG (25 mM) at 48-72 h in both MDA-MB-231 and MCF-10A cells but no such effect was observed in MCF-7 cells. This was correlated to higher activity of ornithine decarboxylase (ODC), a rate-limiting enzyme in polyamine synthesis pathway. Inhibitor of polyamine synthesis (difluoromethylornithine, DFMO, 5 mM) was quite effective in suppressing HG-mediated cell proliferation and ODC activity in MDA-MB-231 and MCF-10A cells. Polyamine (putrescine) levels were significantly elevated with HG treatment in MDA-MB-231 cells. HG exposure also increased the metastasis of MDA-MB-231 cells.

CONCLUSIONS

Our cellular findings indicate that polyamine inhibition should be explored in patient population as a target for future chemotherapeutics in diabetic breast cancer.

Incident Type 2 Diabetes Risk of Selective Estrogen Receptor Modulators in Female Patients with Breast Cancer

Accumulating evidence indicates a link between diabetes and cancer. Selective estrogen receptor modulators (SERMs) may increase diabetes risk via antiestrogen effects. This study investigated incident diabetes risk of SERM treatment and its effects on metastatic cancer and death prevention in breast cancer survivors. This retrospective cohort study included female patients with early-stage breast cancer, treated with or without SERMs, between 2008 and 2020 in a tertiary care hospital in Korea. Four propensity score-matched comparison pairs were designed: SERM use versus non-use, long-term use (≥1500 days) versus non-use, tamoxifen use versus non-use, and toremifene use versus non-use; then, logistic regression analysis was performed for risk analysis. SERMs in general were not associated with an elevated risk of diabetes; however, when used for ≥1500 days, SERMs—especially toremifene—substantially increased diabetes risk in breast cancer patients (OR 1.63, p = 0.048). Meanwhile, long-term SERM treatment was effective at preventing metastatic cancer (OR 0.20, p < 0.001) and death (OR 0.13, p < 0.001). SERM treatment, albeit generally safe and effective, may increase diabetes risk with its long-term use in women with breast cancer. Further studies are required to verify the association between toremifene treatment and incident diabetes.

Metal Complex Formation and Anticancer Activity of Cu(I) and Cu(II) Complexes with Metformin

Metformin has been used for decades in millions of type 2 diabetes mellitus patients. In this time, correlations between metformin use and the occurrence of other disorders have been noted, as well as unpredictable metformin side effects. Diabetes is a significant cancer risk factor, but unexpectedly, metformin-treated diabetic patients have lower cancer incidence. Here, we show that metformin forms stable complexes with copper (II) ions. Both copper(I)/metformin and copper(II)/metformin complexes form adducts with glutathione, the main intracellular antioxidative peptide, found at high levels in cancer cells. Metformin reduces cell number and viability in SW1222 and K562 cells, as well as in K562-200 multidrug-resistant cells. Notably, the antiproliferative effect of metformin is enhanced in the presence of copper ions.

Type 2 Diabetes, Obesity, and Cancer Share Some Common and Critical Pathways

Diabetes and cancer are among the most frequent and complex diseases. Epidemiological evidence showed that the patients suffering from diabetes are significantly at higher risk for a number of cancer types. There are a number of evidence that support the hypothesis that these diseases are interlinked, and obesity may aggravate the risk(s) of type 2 diabetes and cancer. Multi-level unwanted alterations such as (epi-)genetic alterations, changes at the transcriptional level, and altered signaling pathways (receptor, cytoplasmic, and nuclear level) are the major source which promotes a number of complex diseases and such heterogeneous level of complexities are considered as the major barrier in the development of therapeutic agents. With so many known challenges, it is critical to understand the relationships and the commonly shared causes between type 2 diabetes and cancer, which is difficult to unravel and understand. Furthermore, the real complexity arises from contended corroborations that specific drug(s) (individually or in combination) during the treatment of type 2 diabetes may increase or decrease the cancer risk or affect cancer prognosis. In this review article, we have presented the recent and most updated evidence from the studies where the origin, biological background, the correlation between them have been presented or proved. Furthermore, we have summarized the methodological challenges and tasks that are frequently encountered. We have also outlined the physiological links between type 2 diabetes and cancers. Finally, we have presented and summarized the outline of the hallmarks for both these diseases, diabetes and cancer.

Biomechanical and Biophysical Properties of Breast Cancer Cells Under Varying Glycemic Regimens

Diabetes accelerates cancer cell proliferation and metastasis, particularly for cancers of the pancreas, liver, breast, colon, and skin. While pathways linking the 2 disease conditions have been explored extensively, there is a lack of information on whether there could be cytoarchitectural changes induced by glucose which predispose cancer cells to aggressive phenotypes. It was thus hypothesized that exposure to diabetes/high glucose alters the biomechanical and biophysical properties of cancer cells more than the normal cells, which aids in advancing the cancer. For this study, atomic force microscopy indentation was used through microscale probing of multiple human breast cancer cells (MCF-7, MDA-MB-231), and human normal mammary epithelial cells (MCF-10A), under different levels of glycemic stress. These were used to study both benign and malignant breast tissue behaviors. Benign cells (MCF-10A) recorded higher Young's modulus values than malignant cells (MCF-7 and MDA-231) under normoglycemic conditions, which agrees with the current literature. Moreover, exposure to high glucose (for 48 hours) decreased Young's modulus in both benign and malignant cells, to the effect that the cancer cells showed a complete loss in elasticity with high glucose. This provides a possible insight into a link between glycemic stress and cytoskeletal strength. This work suggests that reducing glycemic stress in cancer patients and those at risk can prove beneficial in restoring normal cytoskeletal structure.

Counteracting Chemoresistance with Metformin in Breast Cancers: Targeting Cancer Stem Cells

Despite the leaps and bounds in achieving success in the management and treatment of breast cancers through surgery, chemotherapy, and radiotherapy, breast cancer remains the most frequently occurring cancer in women and the most common cause of cancer-related deaths among women. Systemic therapeutic approaches, such as chemotherapy, although beneficial in treating and curing breast cancer subjects with localized breast tumors, tend to fail in metastatic cases of the disease due to (a) an acquired resistance to the chemotherapeutic drug and (b) the development of intrinsic resistance to therapy. The existence of cancer stem cells (CSCs) plays a crucial role in both acquired and intrinsic chemoresistance. CSCs are less abundant than terminally differentiated cancer cells and confer chemoresistance through a unique altered metabolism and capability to evade the immune response system. Furthermore, CSCs possess active DNA repair systems, transporters that support multidrug resistance (MDR), advanced detoxification processes, and the ability to self-renew and differentiate into tumor progenitor cells, thereby supporting cancer invasion, metastasis, and recurrence/relapse. Hence, current research is focusing on targeting CSCs to overcome resistance and improve the efficacy of the treatment and management of breast cancer. Studies revealed that metformin (1, 1-dimethylbiguanide), a widely used anti-hyperglycemic agent, sensitizes tumor response to various chemotherapeutic drugs. Metformin selectively targets CSCs and improves the hypoxic microenvironment, suppresses the tumor metastasis and inflammation, as well as regulates the metabolic programming, induces apoptosis, and reverses epithelial-mesenchymal transition and MDR. Here, we discuss cancer (breast cancer) and chemoresistance, the molecular mechanisms of chemoresistance in breast cancers, and metformin as a chemo-sensitizing/re-sensitizing agent, with a particular focus on breast CSCs as a critical contributing factor to acquired and intrinsic chemoresistance. The review outlines the prospects and directions for a better understanding and re-purposing of metformin as an anti-cancer/chemo-sensitizing drug in the treatment of breast cancer. It intends to provide a rationale for the use of metformin as a combinatory therapy in a clinical setting.

Therapeutic role of metformin and troglitazone to prevent cancer risk in diabetic patients: evidences from experimental studies

Objectives

It is evident from literature that individual with diabetes mellitus is more prone to develop cancer as compared to non-diabetic one. We aimed to highlight the risk factors that trigger the tumor formation in diabetic individuals and collect evidences regarding the preventive role of anti-diabetics in cancer.

Content

A comprehensive literature was searched in English language using electronic databases including PubMed, ScienceDirect, Medline, Scopus and Embase.

Summary and outlook

Antidiabetic drugs notably metformin and troglitazone, exhibit anticancer effects. Metformin targets energy sensor pathway i. e., AMPK/mTOR which is controlled by LKB1. Whereas. troglitazone activates PPARϒ that modulate the transcription of insulin responsive gene which is essential for lipid and glucose metabolism. Adipocytes are highly expressed with PPARɣ which induce differentiation and regulate adipogenesis. Ligand-driven expression of PPARɣ in myoblast and fibroblast cell lines produces adipocyte differentiation in breast cancer. Prostate cancer that expresses PPARɣ may be suppressed by troglitazone and retinoid which inhibit their proliferation and initiate differentiation. The findings summarized here show that metformin and troglitazone may have the ability to inhibit the cancer cell proliferation via involvement of molecular pathways. This therapeutic intervention will help to control the progression of cancer in diabetic patients.

Effect of type 2 diabetes and antihyperglycemic drug therapy on signs of tumor invasion in papillary thyroid cancer

PURPOSE

This retrospective study investigated the association between worrisome pathological features of papillary thyroid cancer indicative of invasion and type 2 diabetes, as well as antihyperglycemic drug therapy for diabetes.

METHODS

The records of 14,167 patients who had undergone primary surgery for thyroid cancer were retrospectively reviewed and screened for concomitant diabetes. The diabetic and nondiabetic groups were age and gender matched, and further stratified by treatment, including five single antihyperglycemic drugs.

RESULTS

The study population comprised 942 patients, including 471 patients each with and without diabetes. The rate of worrisome pathological features was higher in diabetic patients than in nondiabetic patients (49.26% cf. 30.57%, P < 0.001), mainly reflected by extrathyroidal extension (34.82% cf. 5.94%, P < 0.001) and lymph node metastasis (42.68% cf. 33.55%, P < 0.001). The number of lymph node metastases in those treated with acarbose (0.32) was significantly lower compared with groups given any of the other four antihyperglycemic drugs (ranging from 1.51 to 2.15; P = 0.001 to 0.05).

CONCLUSIONS

Papillary thyroid cancer complicated with type 2 diabetes has a higher risk of invasive tumor growth. Compared with other antihyperglycemic drugs, patients with acarbose had the lowest risk of aggressive tumor growth. These results may evoke pathophysiological hypotheses to be explored in preclinical and clinical studies.

Phenformin as an Anticancer Agent: Challenges and Prospects

Currently, there is increasing evidence linking diabetes mellitus (especially type 2 diabetes mellitus) with carcinogenesis through various biological processes, such as fat-induced chronic inflammation, hyperglycemia, hyperinsulinemia, and angiogenesis. Chemotherapeutic agents are used in the treatment of cancer, but in most cases, patients develop resistance. Phenformin, an oral biguanide drug used to treat type 2 diabetes mellitus, was removed from the market due to a high risk of fatal lactic acidosis. However, it has been shown that phenformin is, with other biguanides, an authentic tumor disruptor, not only by the production of hypoglycemia due to caloric restriction through AMP-activated protein kinase with energy detection (AMPK) but also as a blocker of the mTOR regulatory complex. Moreover, the addition of phenformin eliminates resistance to antiangiogenic tyrosine kinase inhibitors (TKI), which prevent the uncontrolled metabolism of glucose in tumor cells. In this review, we evidence the great potential of phenformin as an anticancer agent. We thoroughly review its mechanism of action and clinical trial assays, specially focusing on current challenges and future perspectives of this promising drug.

Risk Prediction for Contrast-Induced Nephropathy in Cancer Patients Undergoing Computed Tomography under Preventive Measures

Background

Contrast-induced nephropathy (CIN) is a major cause of acute kidney injury in chronic kidney disease. Many cancer patients have risk factors for CIN and frequently undergo contrast-enhanced computed tomography (CECT). We aimed to develop a risk prediction model for CIN in cancer patients undergoing CECT.

Methods

Between 2009 and 2017, 2,240 cancer patients with estimated glomerular filtration rate (eGFR) < 45 mL/min/1.73 m² who underwent CECT with CIN preventive measures were included in a development cohort. Primary outcome was development of CIN, defined as 25% increase in serum creatinine within 2-6 days after contrast exposure. A prediction model was developed using logistic regression analysis. The model was evaluated for prognostic utility in an independent cohort (N = 555).

Results

Overall incidence of CIN was 2.5% (55/2,240). In multivariable analysis, eGFR, diabetes mellitus, and serum albumin level were identified as independent predictors of CIN. A prediction model including eGFR, serum albumin level, and diabetes mellitus was developed, and risk scores ranged from 0 to 6 points. The model demonstrated fair discriminative power (C statistic = 0.733, 95% confidence interval [CI] 0.656-0.810) and good calibration (calibration slope 0.867, 95% Cl 0.719-1.015). In the validation cohort, the model also demonstrated fair discriminative power (C statistic = 0.749, 95% CI 0.648-0.849) and good calibration (calibration slope 0.974, 95% CI 0.634-1.315).

Conclusions

The proposed model has good predictive ability for risk of CIN in cancer patients with chronic kidney disease. This model can aid in risk stratification for CIN in patients undergoing CECT.

Diabetes as a prognostic factor in HER-2 positive breast cancer patients treated with targeted therapy

PURPOSE

Recent studies revealed that metabolic stress influences the outcomes of breast cancer treatment. We sought to evaluate the prognostic effect of type 2 diabetes and find the molecular mechanism of relapses in postoperative HER-2+ breast cancer patients treated with HER-2 targeted therapy.

MATERIALS AND METHODS

We evaluated 190 HER-2+ breast cancer patients (pT1-4N0-2M0) who were treated with surgical resection and trastuzumab (HER-2 targeted therapy) between 2006 and 2015. Survival outcomes and failure patterns were compared between such patients with (n = 12) and without (n = 178) type 2 diabetes.

RESULTS

The median follow-up period was 42.4 months (range 12.0-124.7 months). Twenty-one patients (11.1%) showed relapse (including nine patients with locoregional failure), and three patients (1.6%) died as a result of cancer relapse. One-third of the patients with diabetes experienced relapse (4/12, 33.3%). The 3-year disease-free survival (DFS) and overall survival (OS) rates were 90.7% and 98.6%, respectively. Diabetic patients showed shorter DFS compared with non-diabetic patients (p = 0.006, 74.1% vs. 91.9%). OS was also shorter in diabetic patients compared with non-diabetic patients (p = 0.017, 91.7% vs. 99.1%). Of our interest, the levels of HER-3 and its ligand neuregulin-1 were significantly increased in the tumor specimen in HER-2+ breast cancer patients suffering with type 2 diabetes than that in the euglycemic control group.

CONCLUSIONS

Type 2 diabetes was associated with detrimental effects on survival in postoperative HER-2+ breast cancer patients who were treated with trastuzumab. The poor prognostic effect of diabetes in HER-2+ breast cancer patients could be associated with the high levels of HER-3 and neuregulin 1, thus it should be considered and evaluated more.

Energy oversupply to tissues: a single mechanism possibly underlying multiple cancer risk factors

BACKGROUND AND OBJECTIVES

Several major risk factors for cancer involve vascular oversupply of energy to affected tissues. These include obesity, diabetes and chronic inflammation. Here, we propose a potential mechanistic explanation for the association between energy oversupply and cancer risk, which we call the metabolic cancer suppression hypothesis: We hypothesize that oncogenesis is normally suppressed by organismal physiology that regulates and strictly limits normal energy supply to somatic cells, and that this protection is removed by abnormal oversupply of energy.

METHODOLOGY

We evaluate this hypothesis using a computational model of somatic cell evolution to simulate experimental manipulation of the vascular energy supply to a tissue. The model simulates the evolutionary dynamics of somatic cells during oncogenesis.

RESULTS

In our simulation experiment, we found that under plausible biological assumptions, elevated energy supply to a tissue led to the evolution of elevated energy uptake by somatic cells, leading to the rapid evolution of both defining traits of cancer cells: hyperproliferation, and tissue invasion.

CONCLUSIONS AND IMPLICATIONS

Our results support the hypothesis of metabolic cancer suppression, suggesting that vascular oversupply of energetic resources to somatic cells removes normal energetic limitations on cell proliferation, and that this accelerates cellular evolution toward cancer. Various predictions of this hypothesis are amenable to empirical testing, and have promising implications for translational research toward clinical cancer prevention.

Metformin in cancer

Metformin is a lipophilic biguanide which inhibits hepatic gluconeogenesis and improves peripheral utilization of glucose. It is the first line pharmacotherapy for glucose control in patients with Type 2 diabetes due to its safety, efficacy and tolerability. Metformin exhibits pleotropic effects, which may have beneficial effects on a variety of tissues independent of glucose control. A potential anti-tumourigenic effect of metformin may be mediated by its role in activating AMP-kinase, which in turn inhibits mammalian target of rapamycin (mTOR). Non-AMPK dependent protective pathways may include reduction of insulin, insulin-like growth factor-1, leptin, inflammatory pathways and potentiation of adiponectin, all of which may have a role in tumourigenesis. A role in inhibiting cancer stem cells is also postulated. A number of large scale observational and cohort studies suggest metformin is associated with a reduced risk of a number of cancers, although the data is not conclusive. Recent randomised studies reporting use of metformin in treatment of cancer have revealed mixed results, and the results of much larger randomised trials of metformin as an adjuvant therapy in breast and colorectal cancers are awaited.

Modalities for assessing the nutritional status in patients with diabetes and cancer

Epidemiological data have shown that an increased body mass index (BMI) is associated with a higher risk of various cancers, especially in obese diabetic patients. However, oncologic patients often present nutritional alterations that can worsen their prognosis. The aim of this review is to propose the use of cheaper and easy to use tools to assess the nutritional status of patients with cancer with altered glucose metabolism. Based on a literature review, we propose anthropometric measures to classify the degree of malnutrition. Moreover, the Karnofsky Performance Status (KPS) and the Eastern Cooperative Oncology Group's performance index (ECOG) are useful to assess the functional status of the body; the achievement of nutritional needs can be analysed with the PG-SGA questionnaire, while the quality of life can be investigated using the DTSQ, SF36, EQ-5D questionnaires and the Edmonton Symptom Assessment System. Pre-albumin dosage and lymphocyte count are proposed as nutritional parameters. The degree of hydration can be evaluated through the Bio-Impedance Test (BIA), and energy intake through the dairy food diary, which considers the type of nutrition and the consistency of the meals. It is possible to use a score for each tool used, which is useful to plan an adequate nutritional intervention.

Glucose-regulated phosphorylation of TET2 by AMPK reveals a pathway linking diabetes to cancer

Diabetes is a complex metabolic syndrome that is characterized by prolonged high blood glucose levels and frequently associated with life-threatening complications^1,2. Epidemiological studies have suggested that diabetes is also linked to an increased risk of cancer^3-5. High glucose levels may be a prevailing factor that contributes to the link between diabetes and cancer, but little is known about the molecular basis of this link and how the high glucose state may drive genetic and/or epigenetic alterations that result in a cancer phenotype. Here we show that hyperglycaemic conditions have an adverse effect on the DNA 5-hydroxymethylome. We identify the tumour suppressor TET2 as a substrate of the AMP-activated kinase (AMPK), which phosphorylates TET2 at serine 99, thereby stabilizing the tumour suppressor. Increased glucose levels impede AMPK-mediated phosphorylation at serine 99, which results in the destabilization of TET2 followed by dysregulation of both 5-hydroxymethylcytosine (5hmC) and the tumour suppressive function of TET2 in vitro and in vivo. Treatment with the anti-diabetic drug metformin protects AMPK-mediated phosphorylation of serine 99, thereby increasing TET2 stability and 5hmC levels. These findings define a novel 'phospho-switch' that regulates TET2 stability and a regulatory pathway that links glucose and AMPK to TET2 and 5hmC, which connects diabetes to cancer. Our data also unravel an epigenetic pathway by which metformin mediates tumour suppression. Thus, this study presents a new model for how a pernicious environment can directly reprogram the epigenome towards an oncogenic state, offering a potential strategy for cancer prevention and treatment.

Metformin and cancer: An existing drug for cancer prevention and therapy

Metformin is a standard clinical drug used to treat type 2 diabetes mellitus (T2DM) and polycystic ovary syndrome. Recently, epidemiological studies and meta-analyses have revealed that patients with T2DM have a lower incidence of tumor development than healthy controls and that patients diagnosed with cancer have a lower risk of mortality when treated with metformin, demonstrating an association between metformin and tumorigenesis. In vivo and in vitro studies have revealed that metformin has a direct antitumor effect, which may depress tumor proliferation and induce the apoptosis, autophagy and cell cycle arrest of tumor cells. The mechanism underpinning the antitumor effect of metformin has not been well established. Studies have demonstrated that reducing insulin and insulin-like growth factor levels in the peripheral blood circulation may lead to the inhibition of phosphoinositide 3-kinase/Akt/mechanistic target of rapamycin (mTOR) signaling or activation of AMP-activated protein kinase, which inhibits mTOR signaling, a process that may be associated with the antitumor effect of metformin. The present review primarily focuses on the recent progress in understanding the function of metformin in tumor development.

Metformin, an Anti-diabetic Drug to Target Leukemia

Metformin, a widely used anti-diabetic molecule, has attracted a strong interest in the last 10 years as a possible new anti-cancer molecule. Metformin acts by interfering with mitochondrial respiration, leading to an activation of the AMPK tumor-suppressive pathway to promote catabolic-energy saving reactions and block anabolic ones that are associated with abnormal cell proliferation. Metformin also acts at the organism level. In type 2 diabetes patients, metformin reduces hyperglycemia and increases insulin sensitivity by enhancing insulin-stimulated glucose uptake in muscles, liver, and adipose tissue and by reducing glucose output by the liver. Lowering insulin and insulin-like growth factor 1 (IGF-1) levels that stimulate cancer growth could be important features of metformin's mode of action. Despite continuous progress in treatments with the use of targeted therapies and now immunotherapies, acute leukemias are still of very poor prognosis for relapse patients, demonstrating an important need for new treatments deriving from the identification of their pathological supportive mechanisms. In the last decade, it has been realized that if cancer cells modify and reprogram their metabolism to feed their intense biochemical needs associated with their runaway proliferation, they develop metabolic addictions that could represent attractive targets for new therapeutic strategies that intend to starve and kill cancer cells. This Mini Review explores the anti-leukemic potential of metformin and its mode of action on leukemia metabolism.

Effects of Resveratrol, Lovastatin and the mTOR-Inhibitor RAD-001 on Insulin-Induced Genomic Damage In Vitro

Diabetes mellitus (DM) is one of the major current health problems due to lifestyle changes. Before diagnosis and in the early years of disease, insulin blood levels are elevated. However, insulin generates low levels of reactive oxygen species (ROS) which are integral to the regulation of a variety of intracellular signaling pathways, but excess levels of insulin may also lead to DNA oxidation and DNA damage. Three pharmaceutical compounds, resveratrol, lovastatin and the mTOR-inhibitor RAD-001, were investigated due to their known beneficial effects. They showed protective properties against genotoxic damage and significantly reduced ROS after in vitro treatment of cultured cells with insulin. Therefore, the selected pharmaceuticals may be attractive candidates to be considered for support of DM therapy.

Metformin-treated cancer cells modulate macrophage polarization through AMPK-NF-κB signaling

Accumulating evidence is indicating metformin to possess the potential ability in preventing tumor development and suppressing cancer growth. However, the exact mechanism of its antitumorigenic effects is still not clear. We found that metformin suppressed the ability of cancer to skew macrophage toward M2 phenotype. Metformin treated cancer cells increased macrophage expression of M1-related cytokines IL-12 and TNF-α and attenuated M2-related cytokines IL-8, IL-10, and TGF-β expression. Furthermore, metformin treated cancer cells displayed inhibited secretion of IL-4, IL-10 and IL-13; cytokines important for inducing M2 macrophages. Conversely, M1 inducing cytokine IFN-γ was upper-regulated in cancer cells. Additionally, through increasing AMPK and p65 phosphorylation, metformin treatment activated AMPK-NF-κB signaling of cancer cells that participate in regulating M1 and M2 inducing cytokines expression. Moreover, Compound C, an AMPK inhibitor, significantly increased IL-4, IL-10, and IL-13 expression while BAY-117082, an NF-κB inhibitor, decreased expression. In metformin-treated tumor tissue, the percentage of M2-like macrophages decreased while M1-like macrophages increased. These findings suggest that metformin activates cancer AMPK-NF-κB signaling, a pathway involved in regulating M1/M2 expression and inducing genes for macrophage polarization to anti-tumor phenotype.

Cancer Prevention During Early Adulthood: Highlights From a Meeting of Experts

Using a life course approach, the Centers for Disease Control and Prevention's Division of Cancer Prevention and Control and the National Association of Chronic Disease Directors co-hosted a 2-day meeting with 15 multidisciplinary experts to consider evidence linking factors in early adulthood to subsequent cancer risk and strategies for putting that evidence into practice to reduce cancer incidence. This paper provides an overview of key themes from those meeting discussions, drawing attention to the influence that early adulthood can have on lifetime cancer risk and potential strategies for intervention during this phase of life. A number of social, behavioral, and environmental factors during early adulthood influence cancer risk, including dietary patterns, physical inactivity, medical conditions (e.g., obesity, diabetes, viral infections), circadian rhythm disruption, chronic stress, and targeted marketing of cancer-causing products (e.g., tobacco, alcohol). Suggestions for translating research into practice are framed in the context of the four strategic directions of the National Prevention Strategy: building healthy and safe community environments; expanding quality preventive services in clinical and community settings; empowering people to make healthy choices; and eliminating health disparities. Promising strategies for prevention among young adults include collaborating with a variety of community sectors as well as mobilizing young adults to serve as advocates for change. Young adults are a heterogeneous demographic group, and targeted efforts are needed to address the unique needs of population subgroups that are often underserved and under-represented in research studies.

Association between Metformin Use and Survival in Nonmetastatic Rectal Cancer Treated with a Curative Resection: A Nationwide Population Study

Purpose

Metformin is associated with an anticancer effect. However, the effects of metformin in rectal cancer are controversial. This study investigated the impact of metformin on the survival of patients with diabetes mellitus and nonmetastatic rectal cancer who underwent curative surgery.

Materials and Methods

The database was provided by the Korea Center Cancer Registry and National Health Insurance Service of the Republic of Korea. A cohort of patients with newly diagnosed rectal cancer between 2005 and 2011 was identified. Drug exposure was defined as receiving the oral hypoglycemic agent for at least 90 days over the period from 6 months before the initial diagnosis of rectal cancer to the last follow-up.

Results

A total of 4,503 patients were prescribed oral hypoglycemic agents and classified as the diabetic group, of which 3,694 patients received metformin for at least 90 days. Unadjusted analyses showed a significantly higher overall survival (hazard ratio, 0.596; 95% confidence interval, 0.506 to 0.702) and rectal cancer-specific survival (hazard ratio, 0.621; 95% confidence interval, 0.507 to 0.760) in the metformin group than in the nonmetformin group. The adjusted overall survival (hazard ratio, 0.631; 95% confidence interval, 0.527 to 0.755) and cancer-specific survival (hazard ratio, 0.598; 95% confidence interval, 0.479 to 0.746) in the group with a medication possession ratio of 80% or greater was significantly higher than in the group with a medication possession ratio of less than 80%.

Conclusion

Metformin use is associated with overall and cancer-specific survival in diabetic patients with a nonmetastatic rectal cancer treated with a curative resection.

Association Between Interleukin-1A, Interleukin-1B, and Bridging integrator 1 Polymorphisms and Alzheimer's Disease: a standard and Cumulative Meta-analysis

Alzheimer's disease (AD) has been one of the most prevalent health problems among senior population. Interleukin-1A (IL-1A) and IL-1B are two isoforms of IL-1. Recent studies suggested that certain polymorphisms on these two genes are associated with AD. Bridging integrator 1 (BIN1) is considered as common genetic risk factors for AD, whereas different studies have provided various conclusions regarding its role in AD. This study was designed to justify the association between multiple gene polymorphisms and AD through an evidence synthesis approach. We conducted a literature search to identify relevant articles published from 2000 to 2015 from PubMed, Embase, and Cochrane Library, in accordance with inclusion criteria. Pooled odds ratios (ORs) were calculated for the allele model. The effect estimates were summarized by both standard and cumulative meta-analysis. Finally, 54 articles with 88 independent studies were enrolled in this meta-analysis. Mutants in rs1800587 of IL-1A, rs1143634 of IL-1B, rs12989701, and rs744373 of BIN1 were significantly associated with AD onset. The difference effect of same single nucleotide polymorphisms (SNPs) on various ethnicities was also observed in our results. The present meta-analysis suggested that IL-1A, IL-1B, and BIN1 were candidate genes for AD pathogenesis. Polymorphisms of IL-1A, IL-1B, and BIN1 are associated with AD onset.

Anti-α-glucosidase and Anti-dipeptidyl Peptidase-IV Activities of Extracts and Purified Compounds from Vitis thunbergii var. taiwaniana

Ethanol extracts (Et) from the stem (S) and leaf (L) of Vitis thunbergii var. taiwaniana (VTT) were used to investigate yeast α-glucosidase and porcine kidney dipeptidyl peptidase-IV (DPP-IV) inhibitory activities. Both VTT-Et showed complete α-glucosidase inhibition at 0.1 mg/mL; VTT-S-Et and VTT-L-Et showed 26 and 11% DPP-IV inhibition, respectively, at 0.5 mg/mL. The VTT-Et interventions (20 and 50 mg/kg) resulted in improvements in impaired glucose tolerance of diet-induced obese rats. (+)-Hopeaphenol, (+)-vitisin A, and (-)-vitisin B were isolated from the ethyl acetate fractions of S-Et and showed yeast α-glucosidase inhibition (IC50 = 18.30, 1.22, and 1.02 μM) and porcine kidney DPP-IV inhibition (IC50 = 401, 90.75, and 15.3 μM) compared to acarbose (6.39 mM) and sitagliptin (47.35 nM), respectively. Both (+)-vitisin A and (-)-vitisin B showed mixed noncompetitive inhibition against yeast α-glucosidase and porcine kidney DPP-IV, respectively. These results proposed that VTT extracts might through inhibitions against α-glucosidase and DPP-IV improve the impaired glucose tolerance in diet-induced obese rats.

The role of diabetes in acromegaly associated neoplasia

Background

The risk and mortality due to cancer in patients with acromegaly have been previously investigated. Although GH/IGF-1 excess provides a probable pathophysiological explanation, the degree of IGF-1 excess and the role in acromegaly-associated neoplasms of diabetes, a common comorbidity in acromegaly with known association with cancer, remains unclear.

Methods

Acromegalic patients treated in three Canadian referral centers (Toronto, Montreal, Edmonton) were included. All available clinical information was recorded including: age, initial and last percentage of the upper limit of normal (%ULN) IGF-1 levels, comorbidities and other neoplasms (benign and malignant).

Results

408 cases were assessed. 185 were women (45.3%), 126 (30.9%) developed extra-pituitary neoplasms: 55 malignant and 71 benign. The most frequent anatomic site was the gastrointestinal tract (46 [11.3%]), followed by head and neck (36 [8.8%]) and multiple locations (14 [3.4%]). 106 (26.0%) cases had diabetes. Initial IGF-1 was significantly higher in men older than 50 (380.15 vs. 284.78, p = 0.001) when compared to men younger than 50. Diabetics showed significantly higher initial IGF-1 (389.38 vs. 285.27, p = 0.009), as did diabetics older than 50 compared with those without diabetes. 45.3% (48/106) of cases with diabetes developed extra-pituitary neoplasms vs. 24.3% (71/292) without diabetes (p = 0.001, OR: 2.576 95%CI 1.615–4.108). 22.6% (24/106) of cases with diabetes developed malignant tumors vs. 9.2% (27/292), (p < 0.001, OR 2.873, 95%CI 1.572–5.250).

Conclusions

These data suggest that acromegalic patients with diabetes are more likely to develop extra-pituitary neoplasms and their initial IGF-1 levels are higher. The contribution of IGF-1 vs. diabetes alone or in combination in the development of extra-pituitary neoplasms warrants further investigation.

Association of type 2 diabetes mellitus and the risk of colorectal cancer: A meta-analysis and systematic review

AIM: To provide a quantitative assessment of the association between type 2 diabetes mellitus (T2DM) and the risk of colorectal cancer (CRC).

METHODS: Systematic review was conducted thorough MEDLINE, EMBASE, Cochrane Library, and ISI Web of knowledge databases till 31^st January 2014. This meta-analysis included the cohort studies that illustrated relative risk (RR) or odds ratio estimates with 95%CI for the predictive risk of CRC by T2DM. Summary relative risks with 95%CI were analyzed by using an effects summary ratio model. Heterogeneity among studies was assessed by the Cochran’s Q and I² statistics.

RESULTS: The meta analysis of 8 finally selected studies showed a positive correlation of T2DM with the risk of CRC as depicted by effects summary RR of 1.21 (95%CI: 1.02-1.42). Diabetic women showed greater risk of developing CRC as their effect summary RR of 1.22 (95%CI: 1.01-49) with significant overall Z test at 5% level of significance was higher than the effect summary RR of 1.17 (95%CI: 1.00-1.37) of men showing insignificant Z test. The effect summary RR of 1.19 with 95%CI of 1.07-1.33 indicate a positive relationship between DM and increased risk of CRC with significant heterogeneity (I² = 92% and P-value < 0.05).

CONCLUSION: Results from this systematic review and meta-analysis report that diabetic people have an increased risk of CRC as compared to non-diabetics.

Exploring the anti-diabetic potential of Australian Aboriginal and Indian Ayurvedic plant extracts using cell-based assays

BACKGROUND

Plant-derived compounds have been used clinically to treat type 2 diabetes for many years as they also exert additional beneficial effects on various other disorders. The aim of the present study was to investigate the possible mechanism of anti-diabetic activity of twelve (seven Australian Aboriginal and five Indian Ayurvedic) plant extracts.

METHODS

The ethanolic plant extracts were investigated for glucose uptake and adipogenesis in murine 3T3-L1 adipocytes. Cytotoxicity studies were also carried out against two cancerous cell lines, HeLa and A549, to investigate the potential anti-cancer activities of the extracts.

RESULTS

Of the seven Australian Aboriginal plant extracts tested, only Acacia kempeana and Santalum spicatum stimulated glucose uptake in adipocytes. Among the five Indian Ayurvedic plant extracts, only Curculigo orchioides enhanced glucose uptake. With respect to adipogenesis, the Australian plants Acacia tetragonophylla, Beyeria leshnaultii and Euphorbia drumondii and the Indian plants Pterocarpus marsupium, Andrographis paniculata and Curculigo orchioides reduced lipid accumulation in differentiated adipocytes. Extracts of Acacia kempeana and Acacia tetragonophylla showed potent and specific activity against HeLa cells.

CONCLUSIONS

The findings suggest that the plant extracts exert their anti-diabetic properties by different mechanisms, including the stimulation of glucose uptake in adipocytes, inhibition of adipogenesis or both. Apart from their anti-diabetic activities, some of the extracts have potential for the development of chemotherapeutic agents for the treatment of cervical cancer.

Diabetes and cancer: A critical appraisal of the pathogenetic and therapeutic links

Diabetes and cancer represent two common, multifactorial, chronic and potentially fatal diseases, not infrequently co-diagnosed in the same patient. Epidemiological data demonstrate significant increases of the cancer incidence in patients with obesity and diabetes, which is more evident for certain site-specific cancers. Although there is increasing evidence that strongly indicates an augmented risk of cancer in diabetic patients, several confounding factors complicate the ability to precisely assess the risk. Mainly in insulin-resistant states (such as in type 2 diabetes mellitus and in metabolic syndrome), direct associations between obesity-related hyperinsulinemia and increasing circulating insulin-like growth factor-1 (IGF-1) levels have been implicated as key factors in the mechanisms involved in carcinogenesis. Whilst anti-diabetic drugs can increase the cancer risk, anti-proliferative drugs may cause diabetes or aggravate pre-existing diabetes. Additionally, an increasing number of targeted anti-cancer therapies may interfere with the pathways shared by IGF-1 and insulin receptors, showing a adverse effect on glucose metabolism through various mechanisms. Although there is a requirement for large-scale randomized evidence, the present review summarizes the majority of the epidemiological association studies between diabetes and various types of cancer, discussing the pathophysiological mechanisms that may be involved in promoting carcinogenesis in diabetes and the potential impact of different anti-diabetic therapies on cancer risk.

Metformin may function as anti-cancer agent via targeting cancer stem cells: the potential biological significance of tumor-associated miRNAs in breast and pancreatic cancers

Metformin is one of the most used diabetic drugs for the management of type II diabetes mellitus (DM) in the world. Increased numbers of epidemiological and clinical studies have provided convincing evidence supporting the role of metformin in the development and progression of a variety of human tumors including breast and pancreatic cancer. Substantial pre-clinical evidence from in vitro and in vivo experimental studies strongly suggests that metformin has an anti-cancer activity mediated through the regulation of several cell signaling pathways including activation of AMP kinase (AMPK), and other direct and indirect mechanisms; however, the detailed mechanism(s) has not yet been fully understood. The concept of cancer stem cells (CSCs) has gained significant attention in recent years due its identification and defining its clinical implications in many different tumors including breast cancer and pancreatic cancer. In this review, we will discuss the protective role of metformin in the development of breast and pancreatic cancers. We will further discuss the role of metformin as an anti-cancer agent, which is in part mediated through targeting CSCs. Finally, we will discuss the potential role of metformin in the modulation of tumor-associated or CSC-associated microRNAs (miRNAs) as part of the novel mechanism of action of metformin in the development and progression of breast and pancreatic cancers.

Diabetes mellitus: influences on cancer risk

Diabetes mellitus and cancer are common conditions, and their co-diagnosis in the same individual is not infrequent. The relative risks associated with type 2 diabetes are greater than twofold for hepatic, pancreatic, and endometrial cancers. The relative risk is somewhat lower, at 1.2-1.5-fold for colorectal, breast, and bladder cancers. In comparison, the relative risk of lung cancer is less than 1. The evidence for other malignancies (e.g. kidney, non-Hodgkin lymphoma) is inconclusive, whereas prostatic cancer occurs less frequently in male patients with diabetes. The potential biologic links between the two diseases are incompletely understood. Evidence from observational studies suggests that some medications used to treat hyperglycemia are associated with either increased or reduced risk of cancer. Whereas anti-diabetic drugs have a minor influence on cancer risk, drugs used to treat cancer may either cause diabetes or worsen pre-existing diabetes. If hyperinsulinemia acts as a critical link between the observed increased cancer risk and type 2 diabetes, one would predict that patients with type 1 diabetes would have a different cancer risk pattern than patients with type 2 diabetes because the former patients are exposed to lower levels of exogenous administered insulin. Obtained results showed that patients with type 1 diabetes had elevated risks of cancers of the stomach, cervix, and endometrium. Type 1 diabetes is associated with a modest excess cancer risk overall and risks of specific cancers that differ from those associated with type 2 diabetes.

A randomized pilot study with daily walking during adjuvant chemotherapy for patients with breast and colorectal cancer

BACKGROUND

Physical activity during chemotherapy has been shown in several studies to reduce fatigue, improve symptoms and impact positively on health-related quality of life (HRQoL). Challenges associated with intervention studies on physical activity during cancer treatment relate to consistent adherence. The primary objective was to study feasibility and adherence of physical activity intervention among patients with cancer during adjuvant chemotherapy treatment. The secondary objective was to investigate the effects of physical activity on health aspects, including HRQoL, symptoms and surrogate markers for cardiovascular disease.

MATERIAL AND METHODS

This randomized controlled trial included patients with breast cancer (BRCA) and colorectal cancer (CRC) during adjuvant chemotherapy. The intervention continued for 10 weeks and included daily walks of 10 000 steps and a weekly supervised group walk. Adherence was assessed by a pedometer and the number of participants who reported step counts every week and percentage of participants who achieved the target steps every week.

RESULTS

Adherence average reached 91% during the intervention period; in total 74% completed the exercise intervention. The majority of the participants achieved an average of 83% of the target of 10 000 steps per day for 10 weeks. There was a significant increase in daily physical activity (p = 0.016) in the intervention group. Significant differences were also found for some breast cancer-specific symptoms [swelling, mobility and pain (p = 0.045)]. The study showed a relatively small weight gain an average of 0.9 kg in the intervention group and 1.3 kg in the control group.

CONCLUSION

Physical activity in the form of walking is feasible during adjuvant chemotherapy treatment despite increasing symptoms. The physical activity increased in the intervention group during the study time and had a positive impact on breast symptoms and the weight gain was lower in comparison to previous studies.

Bis(acetylacetonato)-oxovanadium(iv), bis(maltolato)-oxovanadium(iv) and sodium metavanadate induce antilipolytic effects by regulating hormone-sensitive lipase and perilipin via activation of Akt

The increased plasma free fatty acid levels due to the deregulated lipolysis in adipocytes are considered as one of the major risk factors for developing type II diabetes. Vanadium compounds are well-known for their antidiabetic effects both on glucose and lipid metabolism, but the mechanisms are still not completely understood. The present study suggests a mechanism for how vanadium compounds exert antilipolytic effects. It demonstrates that all the three vanadium compounds, bis(acetylacetonato)-oxovanadium(iv) (VO(acac)2), bis(maltolato)-oxovanadium(iv) (VO(ma)2) and sodium metavanadate (NaVO3), attenuated basal lipolysis in 3T3L1 adipocytes in a dose- (from 100 to 400 μM for VO(acac)2 and VO(ma)2, 1.0 to 4.0 mM for vanadate) and time-dependent (from 0.5 to 4 h) manner using the glycerol release as a marker of lipolysis. In addition, the three compounds inhibited lipolysis to a different extent. Among them, VO(acac)2 (from 100 to 400 μM) exerted the most potent effect and reduced the lipolysis to ∼60-20% of control after 4 h treatment. The antilipolytic effects of vanadium compounds were further evidenced by a decrease of the levels of phosphorylated HSL at Ser660 and phosphorylated perilipin, which were counteracted by inhibitors of PI3K or Akt but not by an MEK inhibitor. This indicates that though both Akt and ERK pathways are activated by the vanadium compounds, only Akt activation contributes to the antilipolytic effect of the vanadium compounds, without the involvement of ERK activation. We previously demonstrated that VO(acac)2 can block cell cycle progression at the G1/S phase via a highly activated ERK signal in human hepatoma HepG2 cells. Together with this study, we show that similar activated pathways may lead to differential biological consequences for cancer cells and adipocytes, indicating that vanadium compounds may be used in the prevention and treatment of both diabetes and cancer.

Metformin: a metabolic disruptor and anti-diabetic drug to target human leukemia

There is a global and urgent need for expanding our current therapeutical arsenal against leukemia in order to improve their actual cure rates and fight relapse. Targeting the reprogrammed, altered cancer metabolism is an emerging strategy which should profoundly affect cancer cells in their intimate and irrepressible needs and addictions for nutrients uptake and incorporation into the biomass during malignant proliferation. We present here how metformin, an anti-diabetic drug that has attracted a strong interest for its recently discovered anti-cancer properties, can be envisioned as a new adjuvant approach to treat leukemia. Metformin may have a double-edged sword effect (i) by acting on the organism to decrease hyperglycaemia and hyperinsulinemia in diabetic patients and (ii) at the cellular level, by inhibiting the mTORC1-cancer supporting pathway through AMPK-dependent and independent mechanisms.

Breast and prostate cancer survivors in a diabetic cohort: results from the Living with Diabetes Study

OBJECTIVE

Diabetes is more common in cancer survivors than in the general population. The objective of the present study was to determine cancer frequency in a cohort of patients with diabetes and to examine demographic, clinical, and quality of life differences between cancer survivors and their cancer-free peers to inform better individualized care.

METHODS

Self-reported survey data from 3,466 registrants with type 2 diabetes from Australia's National Diabetes Services Scheme (NDSS) were analyzed to compare relevant variables between cancer survivors and cancer-free patients. Analyses were focused on breast and prostate cancer to reflect the most common cancers in women and men, respectively.

RESULTS

Five percent of diabetic women reported a history of breast cancer and 4.2% of men reported a history of prostate cancer. Diabetic patients with a history of breast or prostate cancer were older at time of survey and diabetes diagnosis, less likely to report metformin use (women), and more likely to have two or more comorbidities than their cancer-free peers. More diabetic prostate cancer survivors also reported problems with mobility and performing usual tasks. However, cancer-free diabetic subjects reported a lower diabetes-dependent quality of life than diabetic cancer survivors. There was no association between cancer survivorship and duration of diabetes, indices of glycemic control, obesity, or diabetic complications.

CONCLUSIONS

Cancer survivors comprise a significant minority of diabetic patients that are particularly vulnerable and may benefit from interventions to increase screening and treatment of other comorbidities and promote a healthy lifestyle.

Diabetes treatments and cancer risk: the importance of considering aspects of drug exposure

Investigations of the association between diabetes, diabetes treatments, and cancer risk have raised several epidemiological challenges. In particular, a patient's exposure to glucose-lowering drugs needs to be represented accurately to allow unbiased assessment of the link between the treatments and cancer risk. Many studies have used a simple binary contrast (exposure to a specific drug vs no exposure), which has potentially serious drawbacks. In addition, methods used to determine the duration and cumulative dose of drug exposure differ widely between studies. In this Review, we discuss representation of drug exposure in pharmacoepidemiological investigations of the connection between diabetes drugs and cancer risk. We identify principles that might improve future research (particularly in observational studies), and consider issues related to reverse causation and detection bias.

Effects of metformin dose on cancer risk reduction in patients with type 2 diabetes mellitus: a 6-year follow-up study

STUDY OBJECTIVE

To explore the effects of metformin dose on cancer risk reduction in patients with type 2 diabetes.

DESIGN

Population-based cohort study.

DATA SOURCE

National Health Insurance program Longitudinal Health Insurance Database.

PATIENTS

A total of 65,754 age- and gender-matched patients without diabetes and no previous cancer diagnosis were extracted from the database.

MEASUREMENTS AND MAIN RESULTS

We compared cancer risk among the subjects who had no diabetes, had type 2 diabetes but were not on diabetes drugs, used metformin only, used antidiabetic drugs other than metformin, or used metformin in combination with other antidiabetic drugs. Our results revealed dose-dependent effects of metformin on cancer risk and cancer onset times. A significant decrease in cancer risk was found in the monotherapy group who received more than 360 defined daily doses (DDDs) of metformin (hazard ratio [HR] 0.40, 95% confidence interval [CI] 0.24-0.66). The greatest decrease in cancer risk was observed in patients who took more than 1080 DDDs (HR 0.27, 95% CI 0.09-0.84). Significantly greater dose-dependent effects were seen in patients who used metformin in combination with other antidiabetic drugs.

CONCLUSION

The magnitude of cancer risk reduction and prolonged cancer onset times produced by metformin in patients with type 2 diabetes depended on the dose of metformin, regardless of whether metformin was used alone or combined with other antidiabetic drugs.

Diabetes and risk of subsequent gastric cancer: a population-based cohort study in Taiwan

BACKGROUND

Epidemiological data concerning the association between diabetes and the subsequent development of gastric cancer are controversial. This population-based retrospective cohort study investigated the subsequent risk of gastric cancer for diabetic patients.

METHODS

From claims data of the universal health insurance of Taiwan, we identified 19,625 persons aged ≥20 years newly diagnosed with diabetes during 2000-2005. A comparison group (n = 78,500), frequency matched by age, sex, and calendar year, was randomly selected from people without diabetes. Incidence and hazard ratios (HR) of gastric cancer were ascertained during the follow-up period until 2008. We also explored associations of antidiabetic medicines with the incidence of gastric cancer.

RESULTS

During the follow-up period, 47 subjects in the diabetic group and 216 subjects in the comparison group suffered gastric cancer, with the incidence rates of 4.34 and 4.86 per 10,000 person-years, respectively. During the first 4 years after diabetes diagnosis, the incidence of gastric cancer was relatively low in diabetic patients [adjusted HR = 0.63; 95% confidence interval (CI) = 0.42-0.97]. However, after that time, the diabetic group had a 76% (95% CI = 1.06-2.91) higher risk of developing gastric cancer than the comparison group. In diabetic patients, alpha-glucosidase inhibitors were associated with a significantly decreased risk of gastric cancer (adjusted HR = 0.38; 95% CI = 0.15-0.96).

CONCLUSIONS

Our findings suggested that the association between diabetes and subsequent risk of gastric cancer may vary over time. Increased risk of gastric cancer was observed in patients with longer duration of diabetes.

Branched motifs enable long-range interactions in signaling networks through retrograde propagation

Branched structures arise in the intra-cellular signaling network when a molecule is involved in multiple enzyme-substrate reaction cascades. Such branched motifs are involved in key biological processes, e.g., immune response activated by T-cell and B-cell receptors. In this paper, we demonstrate long-range communication through retrograde propagation between branches of signaling pathways whose molecules do not directly interact. Our numerical simulations and experiments on a system comprising branches with JNK and p38MAPK as terminal molecules respectively that share a common MAP3K enzyme MEKK3/4 show that perturbing an enzyme in one branch can result in a series of changes in the activity levels of molecules “upstream” to the enzyme that eventually reaches the branch-point and affects other branches. In the absence of any evidence for explicit feedback regulation between the functionally distinct JNK and p38MAPK pathways, the experimentally observed modulation of phosphorylation amplitudes in the two pathways when a terminal kinase is inhibited implies the existence of long-range coordination through retrograde information propagation previously demonstrated in single linear reaction pathways. An important aspect of retrograde propagation in branched pathways that is distinct from previous work on retroactivity focusing exclusively on single chains is that varying the type of perturbation, e.g., between pharmaceutical agent mediated inhibition of phosphorylation or suppression of protein expression, can result in opposing responses in the other branches. This can have potential significance in designing drugs targeting key molecules which regulate multiple pathways implicated in systems-level diseases such as cancer and diabetes.

Associations between diabetes, leanness, and the risk of death in the Japanese general population: the Jichi Medical School Cohort Study

OBJECTIVE

To examine the BMI-stratified associations between diabetes and the risks of all-cause death, cardiovascular disease (CVD) death, and cancer death.

RESEARCH DESIGN AND METHODS

Using a prospective study with 12 rural Japanese general populations (n = 3,641, mean age, 53.7 years; 33.5% men), we examined the associations between diabetes and the risk of all-cause death, CVD death, and cancer death. We also examined the effects of BMI and age on such associations.

RESULTS

During an average duration of 10.2 years (37,278 person-years), 240 deaths occurred (54 deaths from CVD, 101 from cancer, and 85 from other causes). Cox regression analysis showed leanness (defined as the lowest quartile of entire BMI; mean, 19.5 kg/m(2)), but not obesity (BMI ≥25 kg/m(2)), and diabetes were independently associated with an increased risk of all-cause death (hazard ratio [HR] 1.70 and 1.65, respectively; both P < 0.01.). Stratification with cause-specific deaths showed that leanness and obesity were associated with CVD death (HR 3.77 and 2.94, respectively), whereas diabetes was associated with cancer death (HR 1.87; all P < 0.05). The increased risk of all-cause death in diabetes was substantially higher in lean subjects aged <65 years (HR 3.4) or those aged ≥65 years (HR 4.2), whereas the risk in obese diabetes patients was significant only in subjects aged <65 years (HR 2.32; all P < 0.05).

CONCLUSIONS

Among the Japanese general population, diabetes confers an increased risk of all-cause death. Particular attention must be paid to the pronounced high mortality in diabetes accompanied with leanness, regardless of age.

Metformin and cancer

Type 2 diabetes mellitus is a rising cause of cardiovascular morbidity and mortality. A number of studies have also identified diabetic patients as having increased risk for the development of cancer. Metformin is a widely prescribed antidiabetic drug with an established efficacy coupled with a favorable safety profile and low cost. An increasing number of studies have associated metformin treatment with a decrease of cancer risk. Moreover, metformin has also been associated with improved outcomes in cancer patients. These possible pleiotropic effects of metformin may establish metformin as a cancer prevention and treatment option. However, any favorable effects of metformin on cancer are not always corroborated by clinical trials. Larger studies are expected to better investigate the possible antineoplastic effects of metformin.

Diabetes and cancer: Could vitamin D provide the link?

Diabetes and cancer are common diseases that may co-exist in the same individual. There is significant evidence that patients with diabetes have increased risk of developing certain cancers, especially colorectal, pancreatic and primary hepatic cancer. There is also good evidence that low levels of vitamin D are associated with increased risk of diabetes and increased risk of colorectal, and possibly other, cancers. In this article we propose that low levels of vitamin D may increase the risk of cancer in people with diabetes and describe potential molecular pathways. We suggest that large scale randomised trials of vitamin D supplementation in patients at risk of diabetes, and in patients with established diabetes to examine the effect on cancer risk, are required.

Increased Cardiovascular and Renal Disease but not Reduced Life Expectancy Among Diabetic Participants in the General Northern Greek Population

We compared life expectancy and causes of death based on death certificates of 269 diabetic participants (group A) and 5659 nondiabetic participants (group B) who died from January 1, 1991 to December 31, 2010, in 3 small towns of Northern Greece. Age at death was significantly ( P = .011) higher in group A (77.2 ± 8.7 years) than in group B (75.7 ± 18.9 years). Males with diabetes lived longer with a mean difference of 4.7 (2.8-6.6) years ( P < .001), whereas females without diabetes lived longer, with a mean difference of 2.3 (1.1-5.6) years ( P = .004). Diabetic participants died more frequently of myocardial infarction ( P = .001), chronic renal failure ( P < .001), followed by pneumonia ( P = .010) and hyperosmolar non-ketotic coma ( P < .001). Nondiabetic participants died more frequently of lung cancer ( P < .001), old age ( P < .001), and car accidents ( P = .004). In conclusion, the cardiovascular and renal disease burden among diabetic participants did not reduce life expectancy, especially in men.

Diabetes and cancer II: role of diabetes medications and influence of shared risk factors

An association between type 2 diabetes mellitus (DM) and cancer has long been postulated, but the biological mechanism responsible for this association has not been defined. In part one of this review, we discussed the epidemiological evidence for increased risk of cancer, decreased cancer survival, and decreased rates of cancer screening in diabetic patients. Here we review the risk factors shared by cancer and DM and how DM medications play a role in altering cancer risk. Hyperinsulinemia stands out as a major factor contributing to the association between DM and cancer, and modulation of circulating insulin levels by DM medications appears to play an important role in altering cancer risk. Drugs that increase circulating insulin, including exogenous insulin, insulin analogs, and insulin secretagogues, are generally associated with an increased cancer risk. In contrast, drugs that regulate insulin signaling without increasing levels, especially metformin, appear to be associated with a decreased cancer risk. In addition to hyperinsulinemia, the effect of DM medications on other shared risk factors including hyperglycemia, obesity, and oxidative stress as well as demographic factors that may influence the use of certain DM drugs in different populations are described. Further elucidation of the mechanisms behind the association between DM, cancer, and the role of DM medications in modulating cancer risk may aid in the development of better prevention and treatment options for both DM and cancer. Additionally, incorporation of DM medication use into cancer prediction models may lead to the development of improved risk assessment tools for diabetic patients.