SUN-157 Clinical and Demographic Profile of Type 2 Diabetes Patients: an Epidemiology Report from Central India

Objective: Our study aimed to assess the clinical and demographic profile of type 2 diabetes mellitus (T2DM) patients registered at our clinic in Central India. Methods: The current study is a retrospective data analysis of T2DM patients registered at our outpatient clinic located in Central India, Chhattisgarh State- Raipur and Bilaspur from Jan 2016 to Dec 2017. Demographic, clinical characteristics, comorbidities and complications of T2DM patients recorded were extracted from electronic medical records were analyzed. Descriptive statistics were used to report the data. Results: Total 1216 patient records were screened and included in the analysis. Among these patients, 1019 patients were with diabetes. Further analysis revealed 977 (95.8%) T2DM, 34 (3.5%) T1DM, and 8 (0.7%) had MODY, and 197 patients were with other conditions such as hypothyroidism (93; 47%), hypertension (52; 26%), obesity (46; 23%), and hyperthyroidism 3 (2%). Mean (±SD) age of T2DM patients was 50 (±13) years, males and females were 537 (55%) and 440 (45%), respectively. Mean (±SD) BMI, Duration of disease and HBA1c was 27.6 (±5.7) kg/m2, 6.9 (±6.6) years and 9.1 (±2.2)%, respectively. Majority of the patients were prescribed with oral anti-diabetes agents (59%), followed by oral+insulin (19%), insulin (11%) and only medical nutrition therapy (2%). The most common comorbidities associated with T2DM were hypertension (48%), hypothyroidism (12%), and obesity (3%). Nearly 211 (21.6%) patients have macro (CAD [6.2%] and microvascular complications [15.4%]). Neuropathy (13.8%) is the most common complication observed in microvascular complications. Among T2DM patients 82% were uncontrolled (HbA1c >7%) and 18% were controlled (HbA1c >7%) at the time of the first visit to the clinic. After 2-4months of treatment, 16.5% of uncontrolled diabetes patients achieved HbA1c of <7%. Further analysis of the correlation between DOD and HbA1c was negative and there was no significant correlation. Conclusion: The clinical and demographic profile of T2DM patients is similar to rest of our clinics, Pan India. Uncontrolled diabetes is in rising and treatment decision should focus on patients’ demographic and clinical characteristics to individualize treatment strategy for better clinical outcomes.

Dietary downregulation of mutant p53 levels via glucose restriction: mechanisms and implications for tumor therapy

The majority of human tumors express mutant forms of p53 at high levels, promoting gain of oncogenic functions and correlating with disease progression, resistance to therapy and unfavorable prognosis. p53 mutant accumulation in tumors is attributed to the ability to evade degradation by the proteasome, the only currently recognized machinery for p53 disruption. We report here that glucose restriction (GR) induces p53 mutant deacetylation, routing it for degradation via autophagy. Depletion of p53 leads, in turn, to robust autophagic activation and to cell death, while expression of degradation-defective mutant p53 blocks autophagy and enables survival to GR. Furthermore, we found that a carbohydrate-free dietetic regimen that lowers the fasting glucose levels blunts p53 mutant expression and oncogenic activity relative to a normal diet in several animal model systems. These findings indicate that the stability of mutant forms of p53 is influenced by the levels of glucose and by dietetic habits. They also unravel the existence of an inhibitory loop between autophagy and mutant p53 that can be exploited therapeutically.

Abstract 66: Corruption of the activity of the mitochondria citrate transporter, CIC, by mutant forms of p53

Introduction. A distinctive feature of cancer cells is the implementation of the synthesis of fatty acids (FA), (lipogenesis), which is instead suppressed in most normal adult tissues. Because metabolites produced via lipogenesis provide redox potential and influence the activity of enzymes involved in transcription regulation, by turning on this pathway tumor cells might enable metabolic and transcriptional adjustments necessary for survival in various stress conditions. A still unanswered question is whether oncogenes expressed in human tumors directly favor the shift towards lipogenesis and, if so, whether this has consequences for proliferation or for therapy. The initial goal of this study was to identify metabolic gene targets regulated by tumor-derived mutant forms of the p53 gene product, whose role in metabolism is currently unknown.

Results. We found that p53 mutants enhance the expression levels of the mitochondria citrate transporter, CIC. CIC is central to lipogenesis as it scaffolds citrate from the mitochondria to the cytosol, yielding acetyl-CoA, in turn necessary for fatty acid synthesis. Data extracted from gene expression databases, confirmed a strong association between high levels of CIC mRNA and p53 mutant-expressing human tumors, suggesting that up-regulation of CIC is a molecular signature for p53 mutations. CIC up-regulation is also a negative prognostic factor, and a predictor of tumor recurrence, thus mirroring the negative prognostic value of p53 mutant positive tumors. We show that the CIC promoter is transcriptionally up-regulated by mutant p53, via a unique mechanism that involves p53 mutant binding to FOXO-1- and to p53-consensus elements contained therein, as well as a physical interaction between these two proteins. Importantly, while in glucose-deprived cells CIC promoter activity is physiologically shut down, p53 mutants maintain higher levels of CIC transcription in these conditions. This is in contrast with wild-type p53 that suppresses CIC transcription. Furthermore, we demonstrate that inhibition of CIC with a siRNA, or blocking export of citrate to the cytoplasm with a CIC inhibitor, lowers fatty acid levels and impairs survival of p53-mutant tumors. This effect is not seen in pseudo-normal or tumor cells that have a wild-type p53 gene, again suggesting specificity for mutant p53. Additional experiments indicate that by promoting cytoplasmic export of citrate, elevated CIC levels might hamper mitochondrial pathways of energy production.

Conclusions. We have identified the first metabolic signature gene regulated by p53 mutants, CIC, and shown that some tumors expressing these proteins depend upon CIC up-regulation and FA synthesis for survival especially in metabolic stress conditions. Furthermore, we have identified strategies for targeting CIC activity, thus opening new opportunities for the treatment of p53 positive tumors.

Note: This abstract was not presented at the AACR 101st Annual Meeting 2010 because the presenter was unable to attend.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 66.