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Background & Aims Choline kinase α (CHKA) catalyzes conversion of choline to phosphocholine and can contribute to carcinogenesis. Little is known about the role of CHKA in the pathogenesis of hepatocellular carcinoma (HCC). Methods We performed whole-exome and transcriptome sequence analyses of 9 paired HCC and non−tumor-adjacent tissues. We performed tissue chip analyses of 120 primary HCC and non−tumor-adjacent tissues from patients who received surgery in Shanghai, China from January 2006 through December 2009; 48 sets of specimens (HCC and non−tumor-adjacent tissues) were also analyzed. CHKA gene copy number was quantified and findings were validated by quantitative reverse transcription polymerase chain reaction analysis. CHKA messenger RNA and protein levels were determined by polymerase chain reaction, immunohistochemical, and immunoblot analyses. CHKA was examined in 2 hepatocyte cell lines and 7 HCC-derived cell lines, and knocked down with small interfering RNAs in 3 HCC cell lines. Cells were analyzed in proliferation, wound healing, migration, and invasion assays. Cells were injected into tail veins of mice and tumor growth and metastasis were quantified. Immunoprecipitation and immunofluorescence assays were conducted to determine interactions between CHKA and the epidermal growth factor receptor (EGFR) and the mechanistic target of rapamycin complex 2. Results Levels of CHKA messenger RNA were frequently increased in HCC tissues compared with nontumor tissues; increased expression was associated with amplification at the CHKA loci. Tumors that expressed high levels of CHKA had more aggressive phenotypes, and patients with these tumors had shorter survival times after surgery compared to patients whose tumors expressed low levels of CHKA. HCC cell lines that stably overexpressed CHKA had higher levels of migration and invasion than control HCC cells, and formed larger xenograft tumors with more metastases in mice compared to HCC cells that did not overexpress CHKA. CHKA was required for physical interaction between EGFR and mechanistic target of rapamycin complex 2. This complex was required for HCC cells to form metastatic xenograft tumors in mice and to become resistant to EGFR inhibitors. Conclusions We found levels of CHKA to be increased in human HCCs compared to nontumor tissues, and increased expression to be associated with tumor aggressiveness and reduced survival times of patients. Overexpression of CHKA in HCC cell lines increased their invasiveness, resistance to EGFR inhibitors, and ability to form metastatic tumors in mice by promoting interaction of EGFR with mechanistic target of rapamycin complex 2. [ABSTRACT FROM AUTHOR]

Aromatic hydrocarbons are usually metabolized to the central intermediate benzoyl-coenzyme A (CoA) prior to ring cleavage. 6-Oxocyclohex-1-ene-1-carbonyl-CoA hydrolase, a key enzyme involved in the reductive benzene ring cleavage, encoded by the bam A gene can serve as a functional biomarker for detecting anaerobic degradation of aromatic compounds in different environments. In the present study, we examined the diversity the bacterial bam A gene in oil field. We sequenced bam A fragments that were PCR amplified from the microbial biomass of two mesophilic oil producing reservoirs during a period of four months. The results showed the presence and a higher diversity of bam A gene than previous studies, indicating its potential involvement in degrading aromatic hydrocarbons through anaerobic biochemical pathways in oil fields. The bam A gene sequences were affiliated to bacteria that are known to degrade aromatics, including Azoarcus , Georgfuchsia , Sulfuritalea , Peptococcaceae and Syntrophus . Differences of composition and diversity of bam A gene sequences over a period of four months in these oil reservoirs showed that it is necessary to monitor functional genes over a period of time to fully establish their significance to any specific process at any site. [ABSTRACT FROM AUTHOR]

Due to the existence of cancer stem cells (CSCs), persistence and relapse of human hepatocellular carcinoma (HCC) are common after treatment with existing anti-cancer therapies. Emerging evidence indicates that lipopolysaccharide (LPS) plays a crucial role in aggravating HCC, but information about the effect of LPS on CSCs of HCC remains scant. Here, we report that the stemness of CD133(+) CSCs sorted from the human HCC cell line Huh7 was maintained well when cells were cultured with LPS. The reduction of CD133 expression was much lesser in cultured CSCs in the presence of LPS. In response to LPS stimulation, CSCs showed an increase in their activity of clonogenesis and tumorigenesis. LPS also supported maintaining CSC abilities of migration, invasion, and chemo-resistance. Treatment with HIF-1α-specific siRNA significantly reduced CD133 expression by CSCs at both mRNA and protein levels. Further, the expression of HIF-1α and CD133 was reduced in LPS-stimulated CSCs when the NF-κB inhibitor was added to the cell culture. HIF-1α-specific siRNA also effectively counteracted the effect of LPS on maintaining CSC abilities of migration and invasion. These data indicate that LPS, an important mediator in the liver tumor microenvironment, supports the maintenance of CSC stemness through signaling of the NF-κB/HIF-1α pathway. Our current study highlights LPS as a potential target for developing new therapeutic approaches to eliminate CSCs during the treatment of HCC. [ABSTRACT FROM AUTHOR]