Background: Forkhead box protein f1 (Foxf1) is associated with cell differentiation, and may be a key player in bone homoeostasis. However, the effect of Foxf1 on osteogenesis of bone marrow-derived mesenchymal stem cells (BMSCs) and ovariectomy-induced bone loss, as well as its clinical implications, is unknown. Methods: By quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR) and western blotting, we assayed Foxf1 expression in bone tissue, BMSCs, and bone marrow-derived macrophages (BMMs), derived from ovariectomised (OVX) mice, and during osteogenic differentiation and osteoclast differentiation. Using a loss-of-function approach (small interfering RNA [siRNA]-mediated knockdown) in vitro, we examined whether Foxf1 regulates osteoblast differentiation of BMSCs via the Wnt/b-catenin signalling pathway. Furthermore, we assessed the anabolic effect of Foxf1 knockdown (siFoxf1) in OVX mice in vivo. We also assayed the expression of Foxf1 in bone tissue derived from postmenopausal osteoporosis (PMOP) patients and its link with bone mineral density (BMD). Finally, we examined the effect of Foxf1 knockdown on the osteoblastic differentiation of human BMSCs. Findings: Foxf1 expression was significantly increased in bone extract and BMSCs from OVX mice and gradually decreased during osteoblastic differentiation of BMSCs but did not differ significantly in OVX mousederived BMMs or during osteoclast differentiation. In vitro, Foxf1 knockdown markedly increased the expression of osteoblast specific genes, alkaline phosphatase (ALP) activity, and mineralisation. Moreover, siFoxf1 activated the Wnt/b-catenin signalling pathway. The siFoxf1-induced increase in osteogenic differentiation was partly rescued by inhibitor of Wnt signalling (DKK1). In OVX mice, Foxf1 siRNA significantly reduced bone loss by enhancing bone formation. Foxf1 expression levels negatively correlated with reduced bone mass and bone formation in bone tissue from PMOP patients. Finally, Foxf1 knockdown significantly promoted osteogenesis by human BMSCs. Interpretation: Our findings indicate that Foxf1 knockdown promotes BMSC osteogenesis and prevents OVXinduced bone loss. Therefore, Foxf1 has potential as a biomarker of osteogenesis and may be a therapeutic target for PMOP.

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Background: Over the next 20 years, oropharyngeal cancers (OPC) will represent the majority of head and neck cancers (HNCs) in the United States. It is estimated that human papillomavirus (HPV) may account for as much as 70% to 80% of OPCs in North America and in certain parts of Europe. It is hence crucial to understand the disease risk factors and natural history of oral HPV infections. We hypothesized that poor oral health (by measures such as poor oral hygiene and periodontal disease) leads to a higher degree of oral HPV-16 infections within a patient cohort from a dental school clinic. This study aims to test this hypothesis and gauge possible disease associations before larger scale studies. Subjects and Methods: 223 participants were recruited in this study from the University of Queensland Dental School clinic. Clinical oral health parameters (such as oral hygiene measures and periodontal disease measurements) have been examined and determined by dental professionals. We have collected oral rinse samples from these volunteers. Results: 10 (4.5%) out of 223 participants were found to have HPV-16 DNA in their oral rinse samples using NB2 endpoint PCR and Sanger sequencing. Within the HPV-16 DNA positive subjects, 7 (70%) and 3 (30%) were associated with poor oral hygiene and periodontal disease, respectively. Conclusion: Our results show a trend towards a positive correlation between oral HPV-16 infection and poor clinical oral health status.

Disruption of DNA methylation patterns is one of the hallmarks of cancer. Similar to other cancer types, human papillomavirus (HPV)-driven head and neck cancer (HNC) also reveals alterations in its methylation profile. The intrinsic ability of HPV oncoproteins E6 and E7 to interfere with DNA methyltransferase activity contributes to these methylation changes. There are many genes that have been reported to be differentially methylated in HPV-driven HNC. Some of these genes are involved in major cellular pathways, indicating that DNA methylation, at least in certain instances, may contribute to the development and progression of HPV-driven HNC. Furthermore, the HPV genome itself becomes a target of the cellular DNA methylation machinery. Some of these methylation changes appearing in the viral long control region (LCR) may contribute to uncontrolled oncoprotein expression, leading to carcinogenesis. Consistent with these observations, demethylation therapy appears to have significant effects on HPV-driven HNC. This review article comprehensively summarizes DNA methylation changes and their diagnostic and therapeutic indications in HPV-driven HNC.

The incidence of human papillomavirus (HPV)-positive oropharyngeal cancer (OPC) is rising in high-income countries, including Australia. Increasing evidence suggests that accurate HPV testing is pivotal for clinical decision making and treatment planning in these patients. Recently, the eighth edition of the American Joint Committee on Cancer/Union for International Cancer Control (AJCC/UICC) tumor–node–metastasis (TNM) staging system for OPC (based on the p16INK4a (p16) status) was proposed and has been implemented. However, the applicability of this new staging system is still far from clear. In our study, n = 127 OPC patients from Queensland, Australia were recruited, and the tumor p16 expression in these patients was examined using immunohistochemical (IHC) analysis. HPV-16 genotyping, viral load, and physical status (episomal versus integrated) in the saliva samples of OPC patients were determined using the qPCR method. A good inter-rater agreement (k = 0.612) was found between tumor p16 expression and oral HPV-16 infection in OPC. Importantly, according to the eighth edition staging system, HPV-16 DNA viral load (>10 copies/50 ng) was significantly associated with the advanced stages of OPC. In concordance with previous studies, a mixed HPV-16 form (partially or fully integrated) was predominately found in OPC patients. Taken together, our data support HPV-16 detection in saliva as a screening biomarker to identify people within the community who are at risk of developing OPC.

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Mitotic progression of mammalian cells is tightly regulated by the E3 ubiquitin ligase anaphase promoting complex (APC)/C. Deregulation of APC/C is frequently observed in cancer cells and is suggested to contribute to chromosome instability and cancer predisposition. In this study, we identified Daxx as a novel APC/C inhibitor frequently overexpressed in prostate cancer. Daxx interacts with the APC/C coactivators Cdc20 and Cdh1 in vivo, with the binding of Cdc20 dependent on the consensus destruction boxes near the N-terminal of the Daxx protein. Ectopic expression of Daxx, but not the D-box deleted mutant (DaxxΔD-box), inhibited the degradation of APC/Cdc20 and APC/Cdh1 substrates, leading to a transient delay in mitotic progression. Daxx is frequently upregulated in prostate cancer tissues; the expression level positively correlated with the Gleason score and disease metastasis (P = 0.027 and 0.032, respectively). Furthermore, ectopic expression of Daxx in a non-malignant prostate epithelial cell line induced polyploidy under mitotic stress. Our data suggest that Daxx may function as a novel APC/C inhibitor, which promotes chromosome instability during prostate cancer development.

Hepatocellular carcinoma (HCC) progresses rapidly and is frequently associated with vascular invasion, metastasis, recurrence, and poor prognosis. The expression of connexin32 (Cx32) is frequently downregulated in HCC tissues. In this study, the role of Cx32 in HCC metastasis and proliferation was investigated. The reduction of Cx32 in HCC tissues was significantly associated with increased vascular invasion, increased tumor size, and poor survival. In vitro assays revealed that Cx32 not only suppressed the invasion and migration of HCC cells, but also repressed HCC cell proliferation. Subsequent investigations revealed that Cx32 directly enhanced the acetylation and transcriptional activity of p53, thus upregulating the expression of the tumor metastasis suppressor protein KAI1/CD82, which is a p53 target gene. Additionally, Cx32 negatively regulated the phosphorylation of Akt and the expression of the cell cycle regulation protein cyclin D1, thereby inhibiting the proliferation of HCC cells. Our in vivo nude mice model further confirmed that Cx32 is able to suppress HCC tumor growth and metastasis in nude mice. Our results imply that Cx32 downregulation contributes to the proliferation and metastasis of HCC, and the restoration of Cx32 expression may be a promising strategy for HCC therapy.