Abstract Background Basic studies of oncogenesis have demonstrated that either the elevated production of particular oncogene proteins or the occurrence of qualitative abnormalities in oncogenes can contribute to neoplastic cellular transformation. The purpose of our study was to identify an unique gene that shows cancer-associated expression, and characterizes its function related to human carcinogenesis. Methods We used the differential display (DD) RT-PCR method using normal cervical, cervical cancer, metastatic cervical tissues, and cervical cancer cell lines to identify genes overexpressed in cervical cancers and identified gremlin 1 which was overexpressed in cervical cancers. We determined expression levels of gremlin 1 using Northern blot analysis and immunohistochemical study in various types of human normal and cancer tissues. To understand the tumorigenesis pathway of identified gremlin 1 protein, we performed a yeast two-hybrid screen, GST pull down assay, and immunoprecipitation to identify gremlin 1 interacting proteins. Results DDRT-PCR analysis revealed that gremlin 1 was overexpressed in uterine cervical cancer. We also identified a human gremlin 1 that was overexpressed in various human tumors including carcinomas of the lung, ovary, kidney, breast, colon, pancreas, and sarcoma. PIG-2-transfected HEK 293 cells exhibited growth stimulation and increased telomerase activity. Gremlin 1 interacted with homo sapiens tyrosine 3-monooxygenase/tryptophan 5-monooxygenase activation protein, eta polypeptide (14-3-3 eta; YWHAH). YWHAH protein binding site for gremlin 1 was located between residues 61–80 and gremlin 1 binding site for YWHAH was found to be located between residues 1 to 67. Conclusion Gremlin 1 may play an oncogenic role especially in carcinomas of the uterine cervix, lung, ovary, kidney, breast, colon, pancreas, and sarcoma. Over-expressed gremlin 1 functions by interaction with YWHAH. Therefore, Gremlin 1 and its binding protein YWHAH could be good targets for developing diagnostic and therapeutic strategies against human cancers.
The differential expression profiling with breast normal and tumor tissues, and a breast cancer cell line led to identification of cytokeratin 18 (KT18) gene over-expressed in breast cancer. The expression pattern of KT18 in breast cancer was compare
Abstract Background The Human cervical cancer oncogene (HCCR-1) has been isolated as a human oncoprotein, and has shown strong tumorigenic features. Its potential role in tumorigenesis may result from a negative regulation of the p53 tumor suppressor gene. Results To investigate the biological function of HCCR-1 in the cell, we predicted biological features using bioinformatic tools, and have identified a LETM1 homologous domain at position 75 to 346 of HCCR-1. This domain contains proteins identified from diverse species predicted to be mitochondrial proteins. Fluorescence microscopy and fractionation experiments showed that HCCR-1 is located in mitochondria in the COS-7, MCF-7 and HEK/293 cell lines, and subcompartamentally at the outer membrane in the HEK/293 cell line. The topological structure was revealed as the NH 2 -terminus of HCCR-1 oriented toward the cytoplasm. We also observed that the D1-2 region, at position 1 to 110 of HCCR-1, was required and sufficient for posttranslational mitochondrial import. The function of HCCR-1 on mitochondrial membrane is to retard the intrinsic apoptosis induced by UVC and staurosporine, respectively. Conclusion Our experiments show the biological features of HCCR-1 in the cell, and suggest that uncontrolled expression of HCCR-1 may cause mitochondrial dysfunction that can result in resisting the UVC or staurosporine-induced apoptosis and progressing in the tumor formation.
Oncogene HCCR-1 functions as a negative regulator of the p53 and contributes to tumorigenesis of various human tissues. HCCR transgenic mice developed breast cancers but it is unknown how HCCR-1 contributes to human tumorigenesis. This study identified a HCCR-1-binding protein 1 (HCCRBP-1) as an HCCR binding partner by performing yeast two hybrid screening. Their endogenous interaction was further confirmed by coimmunoprecipitation experiments. These two proteins colocalized in the mitochondria. HCCRBP-1 was overexpressed in various human tumors. In addition, HCCRBP-1 alone converted NIH/3T3 cells into tumor cells in combination with no other oncogenes. HCCRBP-1 induced tumorigenesis by markedly activating PKC activities but decreasing the pro-apoptotic PKC alpha and PKC delta isoform levels. We observed that p53 stabilization also occurred with functional impairment in HCCRBP-1-transfected 293 cells, as indicated by defective induction of p21, MDM2 and bax. Indeed, HCCRBP-1 decreased p21 promoter activity probably via p53 stabilization leading to the defective function. These results indicate that HCCRBP-1 oncogene induces p53 stabilization and thereby contributes to tumorigenesis.
We read with great interest the leading article by Tremosini and coworkers in Gut (2012 doi:10.1136/gutjnl-2011-301951) on the prospective validation of an immunohistochemical panel (glypican 3, heat shock protein 70 and glutamine synthetase) in liver biopsies for diagnosis of very early hepatocellular carcinoma (HCC).1 In this …
Obese women have an increased risk for post-menopausal breast cancer.The physiological mechanism by which obesity contributes to breast tumourigenesis is not understood.We previously showed that HCCR-1 oncogene contributes to breast tumourigenesis as a negative regulator of p53 and detection of HCCR-1 serological level was useful for the diagnosis of breast cancer.In this study, we found that the HCCR-1 level is elevated in breast cancer tissues and cell lines compared to normal breast tissues.We identified apolipoprotein E (ApoE) interacting with HCCR-1.Our data show that HCCR-1 inhibits anti-proliferative effect of ApoE, which was mediated by diminishing ApoE secretion of breast cancer cells.Finally, HCCR-1 induced the severe obesity in transgenic mice.Those obese mice showed severe hyperlipidaemia.In conclusion, our results suggest that HCCR-1 might play a role in the breast tumourigenesis while the overexpression of HCCR-1 induces the obesity probably by inhibiting the cholesterol-lowering effect of ApoE.Therefore, HCCR-1 seems to provide the molecular link between the obesity and the breast cancer risk.
In this study, a stiffness feedback control system for magnetorheological (MR) gel—a smart material of variable stiffness—is proposed, toward the design of a tunable vibration absorber that can adaptively tune to a time varying disturbance in real time. A PID controller was designed to track the required stiffness of the MR gel by controlling the magnitude of the target external magnetic field pervading the MR gel. This paper proposes a novel magnetic field generator that could produce a variable magnetic field with low energy consumption. The performance of the MR gel stiffness control was validated through experiments that showed the MR gel absorber system could be automatically tuned from 56 Hz to 67 Hz under a field of 100 mT to minimize the vibration of the primary system.
Abstract Background A candidate oncogene GIG47, previously known as a neudesin with a neurotrophic activity, was identified by applying the differential expression analysis method. Methods As a first step to understand the molecular role of GIG47, we analyzed the expression profile of GIG47 in multiple human cancers including the breast cancer and characterized its function related to human carcinogenesis. Based on this oncogenic role of GIG47, we then embarked on determining the high-resolution structure of GIG47. We have applied multidimensional heteronuclear NMR methods to GIG47. Results GIG47 was over-expressed in primary breast tumors as well as other human tumors including carcinomas of the uterine cervix, malignant lymphoma, colon, lung, skin, and leukemia. To establish its role in the pathogenesis of breast cancer in humans, we generated stable transfectants of MCF7 cells. The ectopic expression of GIG47 in MCF7 cells promoted the invasiveness in the presence of 50% serum. In addition, it also resulted in the increased tumorigenicity in in vivo tumor formation assay. The tumorigenesis mechanism involving GIG47 might be mediated by the activation of MAPK and PI3K pathways. These results indicate that GIG47 plays a role in the breast tumorigenesis, thus representing a novel target for the treatment of breast cancer. To facilitate the development of GIG47-targeted therapeutics, we determined the structural configuration of GIG47. The high-resolution structure of GIG47 was obtained by combination of NMR and homology modeling. The overall structure of GIG47 has four α -helices and 6 β -strands, arranged in a β 1- α 1- β 2- β 3- α 2- β 4- α 3- α 4- β 5- β 6 topology. There is a potential heme/steroid binding pocket formed between two helices α 2 and α 3. Conclusion The determined three-dimensional structure of GIG47 may facilitate the development of potential anti-cancer agents.