Lakshmi Krishnamoorthy

Serum carotene, vitamin A, and vitamin C levels in breast cancer and cancer of the uterine cervix

Levels of carotene, vitamin A, and vitamin C measured in the serum of patients with cancer of the breast and uterine cervix were compared with levels in healthy controls and patients with benign diseases of the breast and cervix. Serum ascorbate levels were significantly lower in patients with benign diseases of the breast and cervix than in controls. In cancer patients, there was a significant trend of lower serum vitamin levels with increasing stage of the disease.

Serum levels of bone alkaline phosphatase in breast and prostate cancers with bone metastasis

BALP activity in the sera of metastatic patients of breast and prostate malignancy has increased significantly. Our studies with patients in India conform the earlier reports that BALP may have a useful complementary role in the early diagnosis of bone metastases.

Microsatellite instability, promoter methylation and protein expression of the DNA mismatch repair genes in epithelial ovarian cancer.

The role of defective mismatch repair (MMR) system in ovarian carcinoma is not well defined. The purpose of the study was to determine the relationship between microsatellite instability (MSI), promoter methylation and protein expression of MMR genes in epithelial ovarian carcinoma (EOC). MSI and promoter methylation of MLH1, MSH2 and PMS2 genes were studied using PCR methods in the study cohort. A small subset of samples was used to analyze the protein expression by immunohistochemistry (IHC). MSI was observed in >60% of tumor samples and 47% of normal ovaries. MLH1 was methylated in 37.5% and 64.3% EOCs and LMP tumors. The loss of immunoexpression of MMR genes was not seen in ovarian tumors. There was no correlation between MSI, promoter methylation and protein expression of the MMR genes suggesting that each may function independently. MSI is a common event in ovarian carcinoma and may increase the clinical awareness of the subset of tumors.

CORRELATION STUDY OF CARCINO EMBRYONIC ANTIGEN & CANCER ANTIGEN 15.3 IN PRETREATED FEMALE BREAST CANCER PATIENTS

Carcino Embryonic Antigen (CEA) and Cancer Antigen 15.3 (CA15.3) are the most common tumor markers in breast cancer patients. Measurement of circulating tumor markers is a non-invasive quantitative method. Serum levels of CEA and CA 15.3 were studied in female breast cancer patients prior to treatment. To evaluate the utility of these markers, 207 Breast carcinoma patients belonging to all the stages were considered. Healthy age matched 75 female individuals formed the control group. The serum levels of CEA and CA 15.3 were analyzed by Enzyme Linked Immunosorbent Assay (ELISA). Results were taken and compared with stages, tumor size, node and grade. The serum CA 15.3 levels were significant in all the study parameters whereas serum CEA levels showed no significant changes with any of the parameters. Measurement of serum CA 15.3 levels showed significant correlation (24.8%) with advanced stages and larger tumor sizes, whereas serum CEA levels did not show any significant correlation in breast cancer patients prior to treatment.

Investigating impact of Vascular Endothelial Growth Factor Polymorphisms in Epithelial Ovarian Cancers: A Study in the Indian Population

Epithelial ovarian cancer is one of the increasingly incident malignancies that is notorious because of its evasiveness for early diagnosis and high mortality rates. Epithelial ovarian cancers are highly dependent on pathologic vasculature and Vascular Endothelial Growth Factor is known to be one of the most efficient angiogenic factors. Polymorphisms of the VEGF gene, in this study, were assessed for association with the malignancy and other clinico-pathological factors. 300 case samples and 320 age and mensus status matched controls were inculcated into the study. rs699947, rs833061, rs1570360, rs2010963, rs1413711 and rs3025039 were the six single nucleotide polymorphisms that were scrutinized. Genotyping was carried out by polymerase chain reaction and restriction fragment length polymorphism. rs 3025039 showed immense promise as a marker for disease aggression and recurrence and a factor for poor prognosis. rs699947 showed least association with the disease and clinico-pathologic factors studied. rs833061, rs 1570360 showed significant association with some clinico-pathological factors such as bilateral affliction of ovaries and post operative CA-125 levels. rs2010963 associated with presence of ascites in higher volumes. The SNPs under consideration showed no formidable linkage in our study samples. A haplotype analysis (excluding rs699947 and rs1413711) revealed 5 frontrunners being present in >85% of the population with TGGC and CGCC associating significantly as protective and risk factors respectively. These haplotypes showed a dose dependent additive effect of their seeming functionality. This study is unique and a first of its kind carried out in the Indian population of South-east Asia.

Vitamin and provitamin a levels in epithelial cancers: A preliminary study

A major physiological role of retinoids is the regulation of epithelial and epidermal cell differentiation. A total of 285 patients with clinically and histopathologically confirmed diagnosis of various carcinomas (untreated) were selected for the study. The control values of serum beta-carotene and vitamin A levels were established from 50 subjects free of any known pathology. The controls were matched for age and sex. The mean serum levels of beta-carotene and vitamin A have shown a significant difference (p less than 0.001) in all the cancers compared with the controls. In cancer of the oral cavity, the males showed significantly lower levels (p less than 0.01) compared with their female counterparts. In cancer of the lung, however, the mean serum levels of beta-carotene and vitamin A were higher in males compared with females (p less than 0.02). Our results suggest a possible association between vitamin A and epithelial cancer, but whether the deficiency is the cause of the disease or if it is due to the tumor remains unknown.

Evaluation of immunohistochemistry and enzyme linked immunosorbent assay for HER-2/neu expression in breast carcinoma

HER-2 is overexpressed in approximately 20–30% of invasive Breast Cancer. ECD of the HER-2 protein is frequently cleaved and released into the circulation, where it can be detected by ELISA in up to 45% of patients with metastatic breast cancer. The objective of our study was to compare the current methods for the detection of HER-2 protein. Tissue HER-2 levels were studied in 100 breast cancer patients by IHC and compared with serum HER-2 levels by ELISA. IHC frequency was 29%. Serum HER-2 ECD was positive in 42% of patients. A statistically significant correlation was observed. HER-2 detected by IHC correlates significantly with serum HER-2 levels detected by ELISA. Thus, ELISA is a reliable and economical tool to assess the HER-2 status in tumors, when breast tissue sample is not available.

EFFECT OF VITAMIN B 12 AND FOLATE ON HOMOCYSTEINE LEVELS IN COLORECTAL CANCER

Folate and cobalamin (Vitamin B12) are two essential micronutrients involved in one-carbon metabolism, which affects heart disease, neural tube defects and cancer. Methylenetetrahydrofolate reductase, the key enzyme involved in one carbon metabolism produces methyl tetrahydrofolate from methylene tetrahydrofolate, which in turn donates methyl group to homocysteine to generate methionine. There exist two common low function polymorphic variants of the methylenetetrahydrofolate reductase gene involving nucleotides 677 C→T and 1298 A→C, which are associated with hyperhomocysteinemia. These polymorphisms are also linked with increased risk for certain cancers such as breast cancer and at the same time providing a protective effect on colorectal cancer. In this case control study, we have evaluated levels of folic acid, vitamin B12 and homocysteine in patients with colorectal cancer. Folate and homocysteine levels did not differ significantly between the two groups; however an increasing trend was noticed with increase in homocysteine levels. Vitamin B12 levels were increased in cases compared to control group.

Association between plasma homocysteine and riboflavin status in Acute Lymphoblastic Leukemia in children

Remethylation of homocysteine to methionine is dependent on an adequate supply of one or more of the B vitamins like folate, vitamin B12 and vitamin B6. Plasma total homocysteine (tHcy) is also influenced by genetic factors such as polymorphisms in the methylenetetrahydrofolate reductase (MTHFR) gene. MTHFR is a flavo enzyme and a key player in folate metabolism and changes in its activity could modify the susceptibility to Acute Lymphoblastic Leukemia (ALL). In this case — control study we have examined the effect of riboflavin status as measured by erythrocyte glutathione reductase activation coefficient (EGRAC) on homocysteine levels along with vitamin B12 and folate in pediatric ALL. Folate and B12 levels were significantly lower among cases as compared to controls while EGRAC and tHcy did not differ significantly among the groups. The multivariate regression analysis revealed that in the ALL group EGRAC significantly influences tHcy levels suggesting that riboflavin availability may be a predictor of tHcy levels in patients with ALL. This finding may have implications for tHcy lowering therapy.

GSTP1 expression and promoter methylation in epithelial ovarian carcinoma

Context: GSTP1 is a subgroup of glutathione-S-transferase family, which provides cellular protection against free radical and carcinogenic compounds due to its detoxifying function. Altered GSTP1 activity due to down regulation of enzyme activity and DNA methylation has been reported in many tumors, although data for ovarian cancer are few. In this study, we aimed at determining the expression of GSTP1 in relation to the methylation of the GSTP1 promoter in epithelial ovarian cancer (EOC). Materials and Methods: GSTP1 mRNA expression and GSTP1 enzyme concentration were assessed by quantitative reverse transcriptase polymerase chain reaction (PCR) and enzyme-linked immunosorbent assay, respectively, in 88 EOCs, 14 low malignant potential (LMP) tumors, and 20 benign tumors. The promoter methylation of GSTP1 gene was evaluated by methylation-specific PCR. Results: Reduced GSTP1 mRNA expression was observed in 49% EOCs, 21.4% LMP, and 45% benign tumors. Significantly lower levels of plasma GSTP1 were observed in all tumor samples compared to normal. GSTP1 promoter methylation was detected in 10 (11.4%) EOCs and 1 (7.3%) LMP tumors. No methylation was observed in benign tumors and normal ovaries. Conclusions: Our results show that there is a significant down regulation of GSTP1 expression while hypermethylation of the GSTP1 gene promoter is not very frequent in EOC. Further studies are needed to study underlying mechanisms leading to decreased expression.