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In this study, we examined the regulatory role of CCDC34 in the sorafenib sensitivity of hepatocellular carcinoma (HCC) and its functional partners. Wide-type Huh7 and Hep3B and induced sorafenib-resistant (SR) Huh7/SR and Hep3B/SR cells were used as in vitro cell models. Immunofluorescent staining and coimmunoprecipitation were performed to check protein-protein interaction. Cell Counting Kit-8 (CCK-8), terminal deoxynucleotidyl transferase-mediated nick end labeling (TUNEL), PI/Annexin V staining, and western blot analysis were performed to assess cell response to sorafenib. The results showed that CCDC34 upregulation in HCC was associated with poor survival. Huh7/SR and Hep3B/SR cells had significantly higher CCDC34 expression than the parental cell lines. RABL2A expression was significantly upregulated in SR HCC cells and interacted with CCDC34 in its GTP-bound state in Huh7/SR and Hep3B/SR cells. RABL2A depletion sensitized Huh7/SR and Hep3B/SR cells to sorafenib. RABL2A Q80L mutant (GTP-bound state locked), but not S35N mutant (GDP-bound state locked) overexpression increased sorafenib IC50 of Huh7 and Hep3B cells. CCDC34 depletion nearly abrogated the protective effects of RABL2A Q80L overexpression both in vitro and in vivo . RABL2A Q80L overexpression significantly increased the expression of p-p38 and p-JNK, the effects of which were significantly attenuated by CCDC34 depletion. In summary, we infer that the RABL2A-CCDC34 axis plays an important role in mediating p38/MAPK and JNK/MAPK signaling, thereby contributing to acquired sorafenib resistance in HCC.

Background: Lung cancer has the highest mortality rate among cancers worldwide, with non-small cell lung cancer (NSCLC) the most common type. Increasing evidence shows that PHB2 is highly expressed in other cancer types; however, the effects of PHB2 in NSCLC are currently poorly understood. Method: PHB2 expression and its clinical relevance in NSCLC tumor tissues were analyzed using a tissue microarray. The biological role of PHB2 in NSCLC was investigated in vitro and in vivo using immunohistochemistry and immunofluorescence staining, gene expression knockdown and overexpression, cell proliferation assay, flow cytometry, terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay, wound healing assay, Transwell assay, western blot analysis, qRT-PCR, coimmunoprecipitation, and mass spectrometry analysis. Results: Our major finding is that PHB2 facilitates tumorigenesis in NSCLC by interacting with and stabilizing RACK1, which further induces activation of downstream tumor-promoting effectors. PHB2 was found to be overexpressed in NSCLC tumor tissues, and its expression was correlated with clinicopathological features. Furthermore, PHB2 overexpression promoted proliferation, migration, and invasion, whereas PHB2 knockdown enhanced apoptosis in NSCLC cells. The stimulating effect of PHB2 on tumorigenesis was also verified in vivo. In addition, PHB2 interacted with RACK1 and increased its expression through posttranslational modification, which further induced activation of the Akt and FAK pathways. Conclusions: Our results reveal the effects of PHB2 on tumorigenesis and its regulation of RACK1 and RACK1-associated proteins and downstream signaling in NSCLC. We believe that the crosstalk between PHB2 and RACK1 provides us with a great opportunity to design and develop novel therapeutic strategies for NSCLC., Competing Interests: Competing Interests: The authors have declared that no competing interest exists., (© The author(s).)

To investigate the role of HIF-1α genetic polymorphism of c.1772C>T and c.1790G>A in the incidence and prognosis of gliomas in a Chinese cohort, a total of 387 gliomas patients and 437 age- and sex-matched healthy controls were recruited. The genetic polymorphism of c.1772C>T and c.1790G>A was determined. We found that the genotype distribution at c.1772C>T showed significant difference between patients and controls. Multivariable analyses showed a significantly higher risk for gliomas in 1772TT genotype carriers (odds ratio 2.68, with CC as reference). In addition, we also found a significantly higher risk for grade III + IV gliomas was observed in 1772TT genotype carriers (odds ratio 2.21, with CC as reference). The overall survival rates in patients with 1772TT or 1772CT genotype were markedly lower compared with patients with CC (both P < 0.01). Our in vitro studies revealed that HIF-1α regulates the proliferation, migration and invasion of human glioma U251 cells. This study suggests that the c.1772C>T polymorphisms may be used as a molecular marker for gliomas occurrence, grades and clinical outcome in gliomas patients.

To study the relation of 14-3-3 sigma gene promoter hypermethylation and its transcription expression levels in sporadic breast carcinogenesis. Methylation of 14-3-3 sigma gene was detected by sensitive MSP assay in carcinous, non-cancerous, and normal tissue, and its mRNA was also detected by real time PCR based on SYBR Green 1 as well, and protein was detected by west blotting assay. The methylation frequencies of 14-3-3 sigma were 90% in 68 cases of sporadic breast cancer patients. Methylation was presented in portions (2/13, 18%) of hyperplastic samples, and no hypermethylation was presented in normal tissue. The methylation change of 14-3-3 sigma gene was markedly related with various types, grades, and lymph node metastases (P < 0.05), and no significant differences in methylation frequencies were seen between premenopause and postmenopause (P > 0.05). The methylation of 14-3-3 sigma shows reverse relation with its mRNA transcription and expression level (P < 0.05). Only was lymph node metastases strongly associated with poor outcome (P = 0.02). Whether 14-3-3 sigma promoter methylation or not did not affect the 5 years survival rate of sporadic breast cancer patients (P > 0.05). Epigenetics alterations of the 14-3-3 sigma can contribute to reducing or losing expression of 14-3-3 sigma protein, which play an important role in the development of sporadic breast carcinomas and involved in various types, grades, and lymph node metastases. Otherwise, node metastases of breast carcinogenesis patients are strongly associated with poor outcome.

The Epstein-Barr virus (EBV) BamHI A rightward transcripts (BARTs) were originally identified in C15 xenograft of nasopharyngeal carcinoma (NPC) and easily detected in a wide variety of EBV latent infection and EBV-associated tumors. It had been reported that p31 cosmid containing BARTs immortalized monkey epithelial cells, but which particular gene among BARTs family participates in the transformation procedure remains to be identified. RPMS1 is the only full-length cDNA confirmed so far and one of the most abundant spliced forms in BARTs family. To investigate the involvement of RPMS1 gene in NPC, we examined the expression of RPMS1 transcripts in NPC biopsies from Guangdong and its oncogenic potential. Our results revealed that RPMS1 mRNA preferentially expressed in primary NPC to non-carcinoma tissue of nasopharynx and peripheral blood lymphocytes (PBLs) of NPC patients. Furthermore, by introducing RPMS1 ORF into HEK293 cells, these transfectants enhanced the anchorage-independent growth and produced tumors in nude mice. These data imply that RPMS1 gene might play an important role in the development of NPC.

We have cloned a cDNA from chromosome band 17p13.3, designated as HCAP1 (HCC-associated protein 1, originally named HC56). Database searches revealed that HCAP1 shares most of its open reading frame with GEMIN4. Single nucleotide polymorphism (SNP) screening revealed a high incidence of SNP in the coding region of HCAP1 (12 SNP sites). A collection of 140 controls and 22 cases from the Qidong area was genotyped at 6 SNP sites. The 22 cases exhibited higher frequencies of minor alleles than did the controls, and 2 sites revealed significant differences between the controls and the cases. We constructed 2 haplotypes, HCAP1-N (with common alleles at 5 SNP sites) and HCAP1-M (with minor alleles at 5 SNP sites), in a mammalian expression system. Both haplotypes resulted in a remarkable reduction in colony formation and suppression of cell growth after being transfected into the human hepatocellular carcinoma (HCC) cell line. The inhibitory effect of HCAP1-N was stronger than that of HCAP1-M. Different haplotypes also resulted in different gene expression profiles in the Hep3B cell line according to an examination of 588 genes on an Atlas membrane. The expression induced by HCAP1-M caused an up-regulation of genes involved in cellular proliferation and a down-regulation of genes involved in cellular apoptosis and DNA repair. These results, in addition to the statistical data, are biological evidence that the HCAP1-M variant of HCAP1 has a reduced inhibitory effect on hepatocarcinoma cell growth and an impaired DNA repair system. This suggests that HCAP1-M may be related to cancer susceptibility., (Copyright 2003 Wiley-Liss, Inc.)