Status de expressão do receptor de leptina e adiponectina no carcinoma colorretal: A cross-estudo prospectivo seccional / Correlation of leptin and adiponectin receptor expression with clinicopathological parameters in colorectal carcinoma - a cross-sectional prospective study

ABSTRACT Background: Colorectal carcinoma (CRC) is one of the common carcinomas with a rising incidence of metastasis due to its advanced stage of presentation. The existing biomarkers such as CEA (Carcinoembryonic antigen) etc., for prognosis, have low sensitivity and specificity. Hence a need for a newer definitive biomarker. Obesity is the leading cause of CRC. Leptin and adiponectin secreted by adipose tissue have been studied as potential biomarkers in the field of CRC. The present study helps to understand the association of leptin and adiponectin receptors with clinicopathological parameters. Objective: To correlate the various clinicopathological parameters with the tissue expression of leptin and adiponectin receptors in CRC. Methods: It is a cross-sectional prospective study conducted at a tertiary care hospital. Formalin fixed paraffin blocks of all radical resection CRC cases were collected and immunohistochemistry (IHC)was carried out on tumor tissue for leptin and adiponectin receptor. Tumor characteristics and clinical parameters were collected from the hospital medical records. Pearson's correlation coefficient test was used. Results: Immunohistochemistry was performed on 60 cases of CRC. Significant positive correlation of leptin was observed with size, lymph node metastasis, advanced stage, and grade of tumor (P<0.05). A significant correlation between adiponectin receptor and CRC was observed concerning age, stage, lymph node metastasis, distant metastasis and grade of tumor. Conclusion: Positive expression of leptin and negative expression of adiponectin receptors in CRC helps to predict the risk of metastasis.

RESUMO Contexto: O carcinoma colorretal (CCR) é um dos carcinomas comuns com incidência crescente de metástases devido ao seu estágio avançado de apresentação. Os biomarcadores existentes como CEA (antígeno carcinoembrionário) etc., para prognóstico, apresentam baixa sensibilidade e especificidade. Daí a necessidade de um biomarcador definitivo mais recente. A obesidade é a principal causa do CCR. A leptina e a adiponectina secretadas pelo tecido adiposo têm sido estudadas como potenciais biomarcadores na área do CCR. O presente estudo ajuda a compreender a associação dos receptores de leptina e adiponectina com parâmetros clinicopatológicos. Objetivo: Correlacionar os diversos parâmetros clinicopatológicos com a expressão tecidual dos receptores de leptina e adiponectina no CCR. Métodos: Trata-se de um estudo transversal, prospectivo, realizado em um hospital terciário. Blocos de parafina fixados em formalina de todos os casos de CCR de ressecção radical foram coletados e a imuno-histoquímica (IHQ) foi realizada no tecido tumoral para receptor de leptina e adiponectina. As características do tumor e os parâmetros clínicos foram coletados dos prontuários médicos do hospital. Foi utilizado o teste do coeficiente de correlação de Pearson. Resultados: A imunohistoquímica foi realizada em 60 casos de CCR. Correlação positiva significativa da leptina foi observada com tamanho e metástase linfonodal, estágio avançado e grau do tumor (P<0,01). Foi observada uma correlação significativa entre o receptor de adiponectina e o CCR em relação à idade, estágio, metástase linfonodal, metástase à distância e grau do tumor. Conclusão: A expressão positiva de leptina e a expressão negativa de receptores de adiponectina no CCR ajudam a prever o risco de metástase.

Cytotoxicity based screening for radioprotective properties of methanolic extract of Tragia involucrata L. on cultured human peripheral lymphocytes exposed to gamma radiation

Radioprotective drugs of plant origin with bioactives are a boon against ionizing radiation injuries. Tragia involucrata L. (Indian stinging nettle), has medicinal properties and is traditionally used to treat various ailments. Here, we evaluated the radioprotective efficacy of the methanolic whole plant extract of T. involucrata against the damaging effects of gamma radiation. Cultured lymphocytes were treated with methanolic extract for one hour and irradiated with (1-4 Gy) gamma radiation. This pretreatment of lymphocytes with methanolic extract significantly increased the cell viability at 10 μg/mL and reduced the damage to the treated cells compared to the radiation control. In addition, a significant decrease in comet parameters (Comet length and percent DNA in tail and olive moment) and formation of micronuclei (P <0.001) were observed. It also decreased the levels of malondialdehyde, while regulating the status of the total antioxidant capacity, superoxide dismutase, catalase, reduced glutathione, and glutathione transferase (P <0.05) when compared to the radiation control. Similarly, a decrease in caspase 3 cellular activity compared to the radiation control was observed. The results indicated the methanolic extract to be an effective radioprotector up to 4 Gy, by enhancing the antioxidant enzyme levels, scavenging the production of reactive oxygen species, reducing the damaging effects of radiation by increasing the DNA repair mechanism, and by inhibiting the mitochondrial apoptotic pathway. Therefore, methanolic extract of the Indian stinging nettle, Tragia involucrata L. has been proposed as a candidate with a radioprotective property, and further study on animal models would strengthen this claim