Protein expression profiling of nuclear membrane protein reveals potential biomarker of human hepatocellular carcinoma

Abstract

BackgroundComplex molecular events lead to development and progression of liver cirrhosis to HCC. Differentially expressed nuclear membrane associated proteins are responsible for the functional and structural alteration during the progression from cirrhosis to carcinoma. Although alterations/ post translational modifications in protein expression have been extensively quantified, complementary analysis of nuclear membrane proteome changes have been limited. Deciphering the molecular mechanism that differentiate between normal and disease state may lead to identification of biomarkers for carcinoma.ResultsMany proteins displayed differential expression when nuclear membrane proteome of hepatocellular carcinoma (HCC), fibrotic liver, and HepG2 cell line were assessed using 2-DE and ESI-Q-TOF MS/MS. From the down regulated set in HCC, we have identified for the first time a 15 KDa cytochrome b5A (CYB5A), ATP synthase subunit delta (ATPD) and Hemoglobin subunit beta (HBB) with 11, 5 and 22 peptide matches respectively. Furthermore, nitrosylation studies with S-nitrosocysteine followed by immunoblotting with anti SNO-cysteine demonstrated a novel and biologically relevant post translational modification of thiols of CYB5A in HCC specimens only. Immunofluorescence images demonstrated increased protein S-nitrosylation signals in the tumor cells and fibrotic region of HCC tissues. The two other nuclear membrane proteins which were only found to be nitrosylated in case of HCC were up regulated ATP synthase subunit beta (ATPB) and down regulated HBB. The decrease in expression of CYB5A in HCC suggests their possible role in disease progression. Further insight of the functional association of the identified proteins was obtained through KEGG/ REACTOME pathway analysis databases. String 8.3 interaction network shows strong interactions with proteins at high confidence score, which is helpful in characterization of functional abnormalities that may be a causative factor of liver pathology.ConclusionThese findings may have broader implications for understanding the mechanism of development of carcinoma. However, large scale studies will be required for further verification of their critical role in development and progression of HCC.

Huanglongbing pathogen CandidatusLiberibacter asiaticus exploits the energy metabolism and host defence responses of its vector Diaphorina citri

“…Because of the limit on protein loading volumes, more abundant proteins in total protein gels often obscure some proteins of low abundance, although they become visible in subcellular protein gels. This is especially true for membrane-associated proteins, which are usually involved in intercellular protein-protein interactions (PPI) such as vector-pathogen interactions (Gu et al, 2003;Cordero et al, 2009;Khan et al, 2013).…”

“…The comparative study on the differentially expressed subcellular proteomes between normal and pathological status of host has become one of the most effective strategies with respect to revealing the mechanism of pathogen infection and searching for specific biomarkers (Khan et al, 2013). The commonly studied subcellular proteomes include microsomal, mitochondrial and sometimes cytosolic proteins.…”

Deep sequencing and comprehensive expression analysis identifies several molecules potentially related to human poorly differentiated hepatocellular carcinoma

“…In addition, it was reported that aberrant up‐regulation of LRRC1 contributes to human HCC . The nuclear membrane proteome of HCC showed that CYB5A protein was down‐regulated and played a role in oncogenesis of HCC . Our finding showed that up‐regulation of LRRC1 and down‐regulation of CYB5A were associated with tumor grade.…”

Identification of Genes Putatively Involved in Chitin Metabolism and Insecticide Detoxification in the Rice Leaf Folder (Cnaphalocrocis medinalis) Larvae through Transcriptomic Analysis

“…The functional association networks of the 16 chitin metabolism enzymes were generated using STRING 9.1 ( ). Since proteins are often involved in multiple cellular processes or metabolic pathways, these close interaction patterns, evident with high confidence score, are helpful for a better understanding of the activities of each individual protein when observed in a network of associations [ 31 ]. As illustrated in Figure 6 A, the highly conserved protein chitin synthase 1 (krotzkopf verkehrt, kkv) had high score (>0.9) with coexpression evidenced close relation to chitin deacetylase family CDA1 (serp), CDA2 (LCBP1), CDA4 (CG32499) and several other functional partners like obstA and Gasp which has chitin binding domain.…”