Surabhi Gupta

Network of cytokines, integrins and hormones in human trophoblast cells

Trophoblast cells of the developing embryo are unique not only for transporting oxygen and nutrients from the mother to the fetus but also for their array of other functions throughout the pregnancy beginning from the attachment of the blastocyst to the endometrium during the process of implantation, its well regulated invasion in the uterine tissue, proliferation, differentiation and immuno-endocrine functions which subsequently maintain the pregnancy. Using human trophoblast cells in culture, we have tried to understand the molecular mechanisms which regulate such a variety of functions for trophoblast cells. Our RT-PCR studies show that trophoblast cells express the laminin and collagen receptors: integrins alpha1 and alpha2, which are both stimulated by IL-1 and IL-6. These two cytokines, also synthesised by the trophoblast cells themselves, act in an autocrine/paracrine manner to induce their own expression. In addition, IL-1 expression seems to be modulated by a large variety of cytokines and growth factors usually present in the uterine milieu whereas IL-6 expression appears to be significantly stimulated by growth factors like EGF and bFGF only. Hormones like estrogen, progesterone and hCG exhibit a general negative modulation in the expression of IL-1 and IL-6. Since, both IL-1 and IL-6 are known to be involved in the proliferation, invasion and differentiation of trophoblast cells, they might be the key factors involved in trophoblast functions.

High Levels of Cell-Free Circulating Nucleic Acids in Pancreatic Cancer are Associated With Vascular Encasement, Metastasis and Poor Survival

Pancreatic cancer is a highly aggressive disease with rapid invasion and early encasement of blood vessels. Hence, levels of circulating nucleic acids and tumor-associated mutations in them may have clinical importance. We analyzed the levels of circulating tumor DNA and oncogenic k-ras mutation in plasma of patients with pancreatic cancer and correlated their levels with survival and clinicopathological parameters. Higher levels of plasma DNA (>62 ng/mL) was found to associate significantly with lower overall survival time (p = .002), presence of vascular encasement (p = .030) and metastasis (p = .001). However, k-ras mutation status did not correlate with any of the clinicopathological parameters or survival. We conclude that circulating DNA in plasma can be an important predictor of prognosis in pancreatic cancer.

Prognostic significance of extracellular matrix degrading enzymes-cathepsin L and matrix metalloproteases-2 [MMP-2] in human pancreatic cancer.

In the present study, we assessed the expression of extracellular matrix (ECM) degrading proteases—cathepsin L and matrix metalloprotease-2 (MMP-2) in pancreatic cancer tissue and correlated their levels with clinicopathological parameters and survival. Both the proteases were expressed in the majority of the tumor tissues examined. Staining intensity of cathepsin L was significantly higher in the tumor stroma compared to tumor epithelium while MMP-2 staining showed no such difference. Both proteases showed correlation with some of the clinicopathological parameters but only cathepsin L expression in tumor epithelium predicted a poor prognosis for the disease.

Plasma cathepsin L: A prognostic marker for pancreatic cancer

AIM To assess the prognostic significance of cathepsin L, a cysteine protease that degrades the peri-tumoral tissue, in patients with pancreatic cancer. METHODS Plasma samples from 127 pancreatic cancer patients were analyzed for cathepsin L levels by ELISA. Out of these patients, 25 underwent surgery and their paraffin-embedded tissue was analyzed for cathepsin L expression by immunohistochemistry. Survival of patients and clinicopathological parameters was correlated with cathepsin L expression in plasma and tissue using appropriate statistical analysis. RESULTS The mean (± SD) cathepsin L in plasma samples of pancreatic cancer patients was 5.98 ± 2.5 ng/mL that was significantly higher compared to the levels in healthy controls (3.83 ± 0.45) or chronic pancreatitis patients (3.97 ± 1.06). Using ROC curve, a cut-off level of 5.0 ng/mL was decided for survival analysis. Elevated plasma levels of cathepsin L were found to be associated with poor prognosis (P = 0.01) in multivariate analysis. The plasma levels of the protease decreased after surgery. Though no significant correlation was seen between plasma and tissue expression of this protease, a trend did emerge that high cathepsin L expression in tissue correlated with its high levels in plasma. CONCLUSION Cathepsin L levels in plasma of pancreatic cancer patients may be used as a potential prognostic marker for the disease.

Triiodothyronine stimulates VEGF expression and secretion via steroids and HIF-1α in murine Leydig cells

ABSTRACT Leydig cells are the principal steroidogenic cells of the testis. Leydig cells also secrete a number of growth factors including vascular endothelial growth factor (VEGF) which has been shown to regulate both testicular steroidogenesis and spermatogenesis. The thyroid hormone, T3, is known to stimulate steroidogenesis in Leydig cells. T3 has also been shown to stimulate VEGF production in a variety of cell lines. However, studies regarding the effect of T3 on VEGF synthesis and secretion by the Leydig cells were lacking. Therefore, we investigated the effect of T3 on VEGF synthesis and secretion in a mouse Leydig tumour cell line, MLTC-1. The effect of T3 was compared with that of LH/cAMP and hypoxia, two known stimulators of Leydig cell functions. The cells were treated with T3, 8-Br-cAMP (a cAMP analogue), or CoCl2 (a hypoxia mimetic) and VEGF secreted in the cell supernatant was measured using ELISA. The mRNA levels of VEGF were measured by quantitative RT-PCR. In the MLTC-1 cells, T3, 8-Br-cAMP, and CoCl2 stimulated VEGF mRNA levels and the protein secretion. T3 also increased steroid secretion as well as HIF-1α protein levels, two well-established upstream regulators of VEGF. Inhibitors of steroidogenesis as well as HIF-1α resulted in inhibition of T3-stimulated VEGF secretion by the MLTC-1 cells. This suggested a mediatory role of steroids and HIF-1α protein in T3-stimulated VEGF secretion by MLTC-1 cells. The mediation by steroids and HIF-1α were independent of each other. Abbreviations: 8-Br-cAMP: 8-bromo – 3ʹ, 5ʹ cyclic adenosine monophosphate; CoCl2: cobalt chloride; HIF-1α: hypoxia inducible factor −1α; LH: luteinizing hormone; T3: 3, 5, 3ʹ-L-triiodothyronine; VEGF: vascular endothelial growth factor

The Prostate Gland

Development and gross anatomical features Lobes and zones Microstructure and functional regulation Components of prostatic fluid Disorders of prostate gland

Prognostic significance of plasma matrix metalloprotease-2 in pancreatic cancer patients

Background & objectives: Pancreatic cancer has a propensity for wide stromal invasion. Matrix metalloprotease-2 (MMP-2) is a protease that degrades the peri-tumoural tissue and helps in tumour dissemination. Thus, this study was aimed to assess any association of plasma MMP-2 levels with clinicopathological parameters and survival of patients with pancreatic cancer. Methods: Plasma samples from 127 pancreatic cancer patients were analyzed for MMP-2 levels by ELISA. Survival and other clinicopathological parameters of patients were analyzed for any correlation with plasma MMP-2 levels. Results: The mean MMP-2 levels in pancreatic cancer patients were 560.3±222.0 ng/ml which were significantly elevated compared to chronic pancreatitis patients (P<0.001) and healthy individuals (P<0.05). The plasma levels of MMP-2 significantly correlated with tissue expression of this protease (P=0.004). However, MMP-2 levels did not exhibit any association either with clinicopathological parameters or with survival. Interpretation & conclusions: Elevated MMP-2 levels were observed in blood of pancreatic cancer patients which correlated with its tissue expression. However, these levels did not associate with survival or any clinicopathological parameters of patients. Further studies need to be done to confirm the prognostic/clinical significance of MMP-2 in cancer patients before and after surgery.

Immunobiology of trophoblast cells.

Trophoblast cells contribute in all the stages of pregnancy starting from implantation of the embryo to parturition through their unique inherent properties of invasion, proliferation, differentiation and endocrine secretions. Hence, successful outcome of pregnancy depends greatly on the coordinated functioning of the trophoblast cells which is brouth about largely by the timely expression of integrins, adhesion molecules, cytokines, hormones and generation of nitric oxide. Loss of this coordination leads to adverse consequences like early pregnancy failures, preeclampsia, molar pregnancy and choriocarcinoma. In order to have better understanding of normal physiology of pregnancy and to assess the nature and causes of these pathological situations, in depth study of trophoblast function has been carried out by us and several other investigators.