DNA damage and efficacy of DNA repair in patients with type 2 diabetes and coexisting colorectal cancer

INTRODUCTION

 Numerous epidemiological studies have indicated that the frequency of developing certain types of cancer, including colorectal cancer (CRC), is higher in patients with type 2 diabetes. The possible causes of this association have not been fully clarified. It has been suggested that chronic hyperglycemia‑related oxidative stress leading to oxidative DNA damage and impaired DNA repair may contribute to increased risk of cancer in type 2 diabetes.

OBJECTIVES

 The aim of the study was to evaluate the level of DNA damage and efficacy of DNA repair in patients with CRC with and without type 2 diabetes in comparison with healthy controls.

PATIENTS AND METHODS

 The alkaline comet assay was used to assess the level of endogenous oxidative and H2O2‑induced DNA damage and the efficacy of DNA repair in the lymphocytes of patients with type 2 diabetes, with CRC, with type 2 diabetes and CRC, and of healthy people (a total of 32 patients).

RESULTS

 The highest levels of endogenous oxidative and H2O2‑induced DNA damage were found in the lymphocytes of patients with type 2 diabetes and CRC. Additionally, the capacity of DNA repair was significantly decreased in patients with CRC with and without type 2 diabetes.

CONCLUSIONS

 Our findings support the hypothesis that an increased risk of cancer in type 2 diabetes may be associated with oxidative DNA damage; however, impaired DNA repair seems to play a major role in carcinogenesis in people with and without type 2 diabetes.  

Do we have enough data to confirm the link between antidiabetic drug use and cancer development?

Diabetes, especially type 2, is associated with higher risk of certain types of cancer. Potential mechanisms underlying increased cancer risk in diabetics remain unclear. Insulin resistance, hyperinsulinemia, oxidative stress, advanced glycation end products, and chronic low-grade inflammation have been suggested. Interestingly, recent epidemiological studies have also reported an association between cancer incidence and antidiabetic drug therapy. The available data, although inconclusive, may suggest higher cancer risk in patients treated with some hypoglycemic medications (e.g., insulin and sulfonylureas). On the other hand, metformin and rosiglitazone may inhibit cancer progression, especially in breast cancer. In this review, we aim to discuss the current knowledge about this important clinical issue.

Gene polymorphisms and antigen levels of matrix metalloproteinase-1 in type 2 diabetes mellitus coexisting with coronary heart disease

BACKGROUND AND AIM

Diabetes mellitus is a major risk factor for coronary heart disease (CHD). Matrix metalloproteinases (MMPs) can play a pivotal role in the remodelling of extracellular matrix associated with the development of atherosclerosis. Therefore, the aim of the study was to compare the distribution of genotypes and frequency of alleles of two polymorphisms of the MMP-1 gene promoter, an A/G substitution and a 1G/2G insertion, in correlation with antigen levels of matrix metalloproteinase-1 (MMP-1) in type 2 diabetic patients with or without CHD as well as individuals with normal glucose level without CHD.

METHODS

Genotypes of 115 patients with type 2 diabetes mellitus (T2DM) and a subpopulation of 66 patients with coexisting CHD as well as 120 non-diabetic control subjects were determined by PCR-based restriction fragment length polymorphism (PCR-RFLP).

RESULTS

We demonstrated that antigen levels of MMP-1 in the serum of diabetic patients were significantly higher than those of individuals with normal glucose metabolism (p <0.05). Elevated levels of MMP-1 positively correlated with CHD occurrence in T2DM patients (p <0.01). The distribution of genotypes revealed higher frequency of the 2G/2G polymorphism variant in diabetic patients with CHD [OR 5.76, 95% CI (1.24; 26.87)], thus suggesting its strong association with high level of MMP-1. In T2DM patients with coexisting CHD, a higher frequency of the 2G allele of 1G/2G [OR 1.74, CI 95% (1.01; 2.99)] and the G allele of A/G polymorphism [OR 2.15, 95% CI (1.22; 3.80)] was also found.

CONCLUSION

Our results suggest that type 2 diabetes mellitus is linked with elevated blood level of MMP-1, and polymorphisms of the promoter region of its gene might be associated with CHD.

Antimicrobial activity of Polyscias filicifolia cell biomass extracts

Antibacterial activity of extracts of Polyscias filicifolia biomass from bioreactor and callus was determined using the agar disc-diffusion method. The microorganisms Staphylococcus aureus (three strains) showed the highest sensitivity to extracts of P. filicifolia biomass from a bioreactor. The values were comparable with nitrofurantoine used as a standard. Micrococcus flavus, Sreptococcus pyogenes and S. agalatiae were less sensitive. The effect of P. filicifolia callus extract on the above bacteria was less pronounced than that of extracts of biomass from a bioreactor.

[Operative treatment of early cancerous stages and a woman's quality of life]

The operative treatment of early cervical cancerous stages changes the womans quality of life. In the literature there exist works on influence of radical treatment of invasive cervical cancer on the psychical and psychological state of the operated woman. There are few works on the influence of early cancerous stages and social activity of woman. The aim of this work is the assessment of influence of precancerous and cancerous cervical disease of psychical state, partnership, family life and professional and social activity of woman. The material were 153 women aged 20-47 years diagnosed and treated in the Department of Gynaecology and Oncology CM UJ Krakow in the period 1989-1994 for CIN 3 and the cervical cancer in IA stage. During the hospitalisation the women were tested psychologically and were performed special examination with originally constructed formula in 3, 6 and 12 month after the treatment. There has been stated that the precancerous and early cancerous disease diagnosis causes the disease awareness in these women who stated themselves as healthy, causes the fear of the life and saving the reproductive organ and protection the reproduction ability, their further family, professional activities i.e. woman's quality of life.