Assignment of the gene encoding magnesium-dependent protein phosphatase 1alpha (PPM1A) to human chromosome 14q22-->q23 and rat chromosome 6q24 by fluorescence in situ hybridization

Bioinformatics functional analysis of let-7a, miR-34a, and miR-199a/b reveals novel insights into immune system pathways and cancer hallmarks for hepatocellular carcinoma

Let-7a, miR-34a, and miR-199 a/b have gained a great attention as master regulators for cellular processes. In particular, these three micro-RNAs act as potential onco-suppressors for hepatocellular carcinoma. Bioinformatics can reveal the functionality of these micro-RNAs through target prediction and functional annotation analysis. In the current study, in silico analysis using innovative servers (miRror Suite, DAVID, miRGator V3.0, GeneTrail) has demonstrated the combinatorial and the individual target genes of these micro-RNAs and further explored their roles in hepatocellular carcinoma progression. There were 87 common target messenger RNAs (p ≤ 0.05) that were predicted to be regulated by the three micro-RNAs using miRror 2.0 target prediction tool. In addition, the functional enrichment analysis of these targets that was performed by DAVID functional annotation and REACTOME tools revealed two major immune-related pathways, eight hepatocellular carcinoma hallmarks-linked pathways, and two pathways that mediate interconnected processes between immune system and hepatocellular carcinoma hallmarks. Moreover, protein-protein interaction network for the predicted common targets was obtained by using STRING database. The individual analysis of target genes and pathways for the three micro-RNAs of interest using miRGator V3.0 and GeneTrail servers revealed some novel predicted target oncogenes such as SOX4, which we validated experimentally, in addition to some regulated pathways of immune system and hepatocarcinogenesis such as insulin signaling pathway and adipocytokine signaling pathway. In general, our results demonstrate that let-7a, miR-34a, and miR-199 a/b have novel interactions in different immune system pathways and major hepatocellular carcinoma hallmarks. Thus, our findings shed more light on the roles of these miRNAs as cancer silencers.

Expression of PTEN, PPM1A and P-Smad2 in hepatocellular carcinomas and adjacent liver tissues

AIM: To investigate the expressions of PTEN, PPM1A and P-Smad2 in hepatocellular carcinoma (HCC) and their significance.

METHODS: The expressions of PTEN, PPM1A and P-Smad2 in 31 HCC tissues, 25 adjacent liver tissues and 13 non-tumor liver tissues were detected by using Envision immunohistochemical technique.

RESULTS: The positive expression (64.52%) and staining intensity (4.19 ± 3.31) of PTEN in the cytoplasm of HCC were significantly lower and weaker than those in the adjacent or non-tumor liver tissues (97.37%, 7.88 ± 0.93; 100%, 7.77 ± 0.93, respectively) (P < 0.05), and its staining intensity in the cytoplasm of HCC, which belongs to Edmondson pathologic grades II-III and above, was also lower than that of gradeIandI-II. Furthermore, its location in the nucleus or cytoplasm of liver cells was negatively correlated with the progression of liver disease (r = -0.339, P = 0.002); most of PPM1A might be only expressed in the nucleus of adjacent liver tissues, non-HCC tissues or Edmondson gradeIandI-II HCC, but it was mainly expressed in the cytoplasm of HCC with Edmondson grade ≥ II, weakly or negatively expressed in the nucleus (P < 0.05), and its location was negatively correlated with the progression of liver disease (r = -0.45, P = 0.0000). P-Smad2, which was mostly located in the nucleus and cytoplasm of gradeIandI-II HCC, surrounding or non-tumor liver tissues, was only in the nucleus of HCC with Edmondson grade II and above (P < 0.001), and its location was positively correlated with the disease progression (r = 0.224, P = 0.016). Spearman correlation analysis revealed that P-Smad2 was significantly negatively correlated with PTEN and PPM1A (r = -0.748, P = 0.000; r = -0.366, P = 0.001, respectively); and PTEN and PPM1A were positively correlated with HCC carcinogenesis (r = 0.428, P = 0.000).

CONCLUSION: The aberrant location of expression and staining intensity of PTEN, PPM1A and P-Smad2 in HCC and their relationship might have an impact on the pathogenesis of HCC.