A novel RT-PCR method for quantification of human papillomavirus transcripts in archived tissues and its application in oropharyngeal cancer prognosis.

Oropharyngeal squamous cell carcinoma (SCC) is strongly associated with human papillomavirus (HPV) infection, which is distinctively different from most other head and neck cancers. However, a robust quantitative reverse transcription PCR (RT-qPCR) method for comprehensive expression profiling of HPV genes in routinely fixed tissues has not been reported. To address this issue, we have established a new real-time RT-PCR method for the expression profiling of the E6 and E7 oncogenes from 13 high-risk HPV types. This method was validated in cervical cancer and by comparison with another HPV RNA detection method (in situ hybridization) in oropharyngeal tumors. In addition, the expression profiles of selected HPV-related human genes were also analyzed. HPV E6 and E7 expression profiles were then analyzed in 150 archived oropharyngeal SCC samples and compared with other variables and with patient outcomes. Our study showed that RT-qPCR and RNA in situ hybridization were 100% concordant in determining HPV status. HPV transcriptional activity was found in most oropharyngeal SCC (81.3%), a prevalence that is higher than in previous studies. Besides HPV16, three other HPV types were also detected, including 33, 35 and 18. Furthermore, HPV and p16 had essentially identical expression signatures, and both HPV and p16 were prognostic biomarkers for the prediction of disease outcome. Thus, p16 mRNA or protein expression signature is a sensitive and specific surrogate marker for HPV transcriptional activity (all genotypes combined).

A microRNA expression signature for the prognosis of oropharyngeal squamous cell carcinoma.

BACKGROUND: Oropharyngeal squamous cell carcinoma (SCC) rates have been increasing significantly in recent years, despite a decreasing incidence of head and neck cancer in general. Oropharyngeal SCC has many characteristics that are distinct from other head and neck cancers, and thus it is important to focus specifically on cancers arising in this region, with the goal of improving patient outcomes. One important goal is to identify those patients who are likely to fail standard therapy and who could potentially benefit from alternative or targeted treatments. METHODS: In the current study, the prognostic value of microRNAs (miRNAs) was evaluated in patients with oropharyngeal SCC. miRNAs are small, noncoding RNAs that are master regulators of many important biological processes. In total, 150 oropharyngeal tumors were analyzed using the recently developed quantitative polymerase chain reaction-based method for miRNA expression profiling. In addition, the expression of miRNAs was also compared with human papillomavirus (HPV) transcriptional activities. RESULTS: The current study identified 6 miRNAs that were found to be significantly associated with cancer survival. A combined expression signature of these miRNAs was prognostic of oropharyngeal SCC, independent of common clinical features or HPV status. CONCLUSIONS: This new miRNA signature was experimentally validated in an independent oropharyngeal SCC cohort. Furthermore, 5 HPV-related miRNAs were identified, which may help to characterize HPV-induced cancers including both oropharyngeal and cervical SCC.

Stem cell therapy for lower extremity diabetic ulcers: where do we stand?

The impairment of wound healing in diabetic patients is an important clinical problem affecting millions of patients worldwide. Various clinical and basic science studies show that stem cell therapy, as a regenerative medical therapy, can be a good solution. In this paper, we begin with an introduction of the cellular mechanism of the diabetic ulcer. We will then discuss the advantages and limitations of various stem cell therapies that have been under extensive recent study.

Verrucous carcinomas of the head and neck, including those with associated squamous cell carcinoma, lack transcriptionally active high-risk human papillomavirus.

Most oropharyngeal squamous cell carcinomas (SCC) and histologic variants harbor transcriptionally active human papillomavirus (HPV). While HPV DNA can be found in many non-oropharyngeal head and neck carcinomas, transcriptionally active HPV is rare. Verrucous carcinoma is a variant with bland cytology, warty appearance, locally destructive growth, and lack of metastasis when lacking a frankly invasive carcinoma component. Studies have shown variable rates of HPV DNA and p16 protein expression in such tumors but still have not clearly addressed if the virus has biological activity or clinical relevance in the positive cases. Department files were searched for verrucous neoplasms, including pure verrucous carcinoma, verrucous carcinoma with dysplasia or minimal invasion, and SCC arising in verrucous carcinoma (ie, having a major component of frankly invasive carcinoma). p16 immunohistochemistry, HPV DNA polymerase chain reaction (PCR) and E6/E7 mRNA reverse transcription PCR for high-risk HPV types were performed. Of the 49 cases, 6 (12.2%) showed strong (>50%) staining for p16. HPV DNA was detected in 7/49 (14.3%) cases, but only one case was positive for both p16, and HPV DNA. A total of 36 cases yielded sufficient RNA for RT-PCR (18 verrucous carcinomas, 13 atypical verrucous carcinomas, and 5 SCC arising in verrucous carcinoma). All 36 were negative, including the four p16-positive and three HPV DNA-positive tumors tested. Although a minority of verrucous carcinoma lesions are p16 and HPV DNA positive, transcriptionally active high-risk HPV is uniformly absent. These findings argue that verrucous carcinoma and its related squamous cell carcinomas are not HPV-driven tumors.