Interestingly and in contrast with our expectation, we found that the expression level of FBLN-4 and BCRP were downregulated in tumor compared to adjacent normal tissues.
To assess the angiogenic properties of fibulin-4, vascular endothelial growth factor (VEGF) expression and tumor microvessel density were analyzed in ovarian carcinoma by immunohistochemistry.
Evidence is presented linking biotinylation of heat-shock proteins HSP60 and HSP72 with redox biology and immune function, respectively, and biotinylation of the two ENO1 gene products MBP-1 and ENO1 with tumor suppression and glycolysis, respectively.
To assess the angiogenic properties of fibulin-4, vascular endothelial growth factor (VEGF) expression and tumor microvessel density (MVD) were analyzed in the cervical carcinoma cases by immunohistochemistry.
Apart from the known differentially expressed genes on 11q13 (e.g., phosphofurin acidic cluster sorting protein 1 (PACS1) and FOS ligand 1 (FOSL1 or Fra-1)), we detected novel differentially expressed cellular genes located within the tumor suppressor gene region (e.g., EGF-containing fibulin-like extracellular matrix protein 2 (EFEMP2) and leucine rich repeat containing 32 (LRRC32) (also known as glycoprotein-A repetitions predominant (GARP)) that may have potential tumor suppressor functions in this model system of non-tumorigenic and tumorigenic HeLa x fibroblast hybrid cells.
These results demonstrate that malignant cells adapt to hypoxia by modulating alpha-enolase/MBP-1 levels and suggest a mechanism for tumor cell induction of the hyperglycolytic state.
One alternative translated product of the ENO1 gene, known as MBP-1, acts as a negative regulator of the c-myc oncogene, making the ENO1 gene a candidate as a tumour suppressor gene.
Reverse transcription-polymerase chain reaction analysis of RNA from paired human colon tumour and adjacent normal tissue biopsies showed that a significant proportion of tumours had approximately 2-7-fold increases in the level of fibulin-4 mRNA expression.
We propose that MBP1 is the product of a candidate oncogene as rates of both neoplastic transformation and tumour cell growth were shown to be significantly enhanced when the protein is ectopically overexpressed.