The Expression of Leptin and Its Receptor During Tumorigenesis of Diffuse Gliomas such as Astrocytoma and Oligodendroglioma- Grade II, III and IV (NOS)

Abstract

Background: Leptin, an adipocytokine functions via the leptin receptor, OB-Rb that contains an intact intracellular domain and activates the JAK/STAT signalling cascade. It stimulates growth, migration and invasion of cancer cells in vitro potentiating angiogenesis. Recently, the involvement of leptin in tumor progression is being explored. Gliomas exhibit poor prognosis, low survival rates demanding for novel therapeutic regimens resulting in discovery of many potential biomarkers and pharmaceutical targets. We analysed the potential role of leptin and OB-Rb in carcinogenesis of malignant gliomas. Methods: Sixty fresh tissue samples of diffuse gliomas were collected after tumor excision. Real time PCR, immunohistochemical (IHC) analysis and western blot analysis were carried out to assess the expression of leptin and its receptor. Results: The present study demonstrates the expression of leptin and LepR and their involvement in tumor progression. Of the 60 cases, 57 cases (95%) and 53 cases (88.3%) showed amplification for leptin and OB-Rb respectively. The expression of these proteins were measured semi-quantitatively and correlated with degree of malignancy (p<0.05). The bands were visualised on western blot. Conclusion: Leptin may be valued as a pharmaceutical target and anti-leptin compounds could be developed as drugs in mono- or combined therapies for these tumors.

Keywords: Immunohistochemistry; brain tumors; Real-time PCR.

Figure 1

Grade IV – Glioblastoma – x400 - ImmunoHistochemical Expression of Leptin

Figure 2

Grade IV- Glioblastoma- x400 - Immunohistochemical Expression of Leptin Receptor

Figure 3

Western Blot Analysis

Figure 4

Amplification Plot of Leptin - Real-Time PCR

Figure 5

Amplification Plot of Leptin Receptor– Real-Time PCR