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Abstract. Cell proliferation is a major underlying cause of mortality amongst patients with oral squamous cell carcinoma (OSCC); however, the underlying mechanisms have remained to be elucidated. Acylglycerol kinase (AGK) is a multisubstrate lipid kinase, which is known to be associated with the progression of various types of human cancer. The present study aimed to investigate the role of AGK in cell proliferation and cell cycle progression in OSCC. The expression levels of AGK were detected in cancerous and adjacent normal tissue samples from four patients with OSCC undergoing surgical resection, and in OSCC cell lines, using the polymerase chain reaction (PCR) and western blot analysis. The effects of AGK on the proliferation and cell cycle progression of OSCC cells were assessed using a short hairpin RNA lentivirus or expressed-plasmid transfection. In addition, the expression levels of cyclin D1 and p21, as well as cell proliferation-and cell cycle-associated proteins were detected by PCR and western blotting. The results of the present study demonstrated that the expression levels of AGK were significantly higher in the cancerous tissues and OSCC cell lines, compared with the adjacent normal tissues and control cells, respectively. Furthermore, MTT and colony formation assays, in addition to flow cytometric analysis were conducted, in order to assess the role of AGK in cell proliferation and cell cycle progression. The cell proliferation and cell cycle progression of an established OSCC cell line were demonstrated to be decreased following AGK knockdown, and enhanced by AGK overexpression in vitro. Aberrant AGK expression in OSCC was shown to be associated with cell proliferation and cell cycle progression. The results of the present study provide evidence that AGK may promote cell proliferation and cell cycle progression in OSCC.

Toll-like receptors (TLRs) are key members of innate immunity, involved in the defense against diseases, and evidence has revealed that TLR4/5 is involved in the carcinogenesis of hepatic cancer. TLR7 belongs to the TLR family, and its roles in immune-associated hepatic diseases have been well characterized; however, the consequences of agonist targeting of TLR7 in hepatic cancer have not previously been reported. The present study aimed to investigate the effects and underlying mechanisms of Imiquimod, a TLR7 agonist, on hepatic carcinogenesis by affecting the self-renewal of hepatic cancer stem cells. To detect the effects of this TLR7 agonist on hepatic cancer cells an MTT assay, mammosphere formation assay, ALDEFLUOR™ fluorescence-based stem cell sorting was used, and the potential signaling involved in the mechanism was investigated by western blot analysis. The TLR7 agonist Imiquimod demonstrated inhibitory effects on the cell proliferation and mammosphere formation of hepatic cells and stem cells, and decreased stem cell number (P<0.01). These effects may be achieved via the TLR7/IκB kinase/nuclear factor-κB/interleukin-6 signaling pathway, with decreased levels of Snail expression. The present study demonstrated the effects and mechanisms of the TLR7 agonist on hepatic cancer occurred via suppression of the self-renewal of cancer stem cells, indicating novel potential functions of the TLR7 agonist in the treatment of HCC.

Hepatocellular carcinoma (HCC) is one of the most life-threatening diseases in the world. Members of the GTPase of the immunity-associated protein (GIMAP) family are important in regulating apoptosis in cancer cells. However, the basic mechanism of GIMAP in HCC remains to be fully elucidated. The present study was performed to investigate the dysregulation of GIMAP family members in HCC. The techniques of polymerase chain reaction analysis, immunohistochemistry and ELISA were used to analyze the expression of GIMAP5 and GIMAP6 in HCC tissues, in matched noncancerous tissue samples, and in blood samples obtained from patients with HCC and healthy subjects. It was found that the mRNA expression levels of GIMAP5 and GIMAP6 were significantly downregulated in the HCC tumor samples, compared with the levels of expression in the matched non-tumor tissue samples. Similarly, the mRNA expression levels of GIMAP5 and GIMAP6 were also significantly downregulated in the blood samples from patients with HCC, compared with the expression levels in the blood from healthy subjects. At the protein level, it was found that the GIMAP5 and GIMAP6 proteins were expressed at lower levels in the tumor tissue samples, compared with the matched normal tissue samples, and their expression levels were also lower in the blood samples from patients with HCC, compared with the blood samples from the healthy subjects. These data, demonstrating the downregulation of the mRNA and protein expression levels of GIMAP5 and GIMAP6 in the tumor tissues and blood of patients with HCC, suggested the involvement of GIMAP5 and GIMAP6 in the pathogenesis of HCC, and indicate their possible use as diagnostic markers for HCC.

Single nucleotide polymorphisms of XPA gene have been studied in several cancers such as rs10817938, rs2808668. However, the role of XPA polymorphisms in patients with oral squamous cell carcinoma (OSCC) remains unclear. Thus, we analyzed the association of XPA polymorphisms with OSCC risk, clinicopathological characteristics and prognosis in the present study. TaqMan genotyping was used to evaluate the frequency of rs10817938, rs2808668 polymorphisms in OSCC patients. The prognostic significance of these polymorphisms was evaluated using Kaplan-Meier curves, Log-Rank analyses, and the Cox proportional hazard model. Luciferase reporter assay, RT-PCR and western blot were used to determine whether rs10817938 could influence transcription activity and XPA expression. The results showed that individuals carrying TC and CC genotypes had significantly greater risk of developing OSCC (OR = 1.42, 95% CI 1.04–1.93; OR = 2.75, 95% CI 1.32–5.71, respectively) when compared with wild-type TT genotype at rs10817938. OSCC patients with C allele at rs10817938 were more susceptible to lymph metastases, poor pathological differentiation and late TNM stage (OR = 1.67, 95% CI 1.17–2.37; OR = 1.64, 95% CI 1.18–2.28; OR = 1.54, 95% CI 1.11–2.14; respectively). A significant gene-environment interaction between smoking and CC genotype at rs10817938 was observed (COR = 3.60, 95% CI 1.20–10.9) and data also showed that OSCC patients with CC genotype and C allele had worse survival (p<0.001 for both). The T to C substitution at rs10817938 significantly decreased transcription activity of XPA gene, XPA mRNA and protein were also decreased in individuals with C allele at rs10817938. In addition, no significant association of rs2808668 polymorphism with OSCC risk, prognosis could be observed. In conclusion, the present study showed that XPA rs10817938 polymorphism is a functional SNP in vitro and in vivo and a biomarker for poor prognosis in OSCC patients.