Targeted Therapy With PI3K and FGFR Inhibitors on Human Papillomavirus Positive and Negative Tonsillar and Base of Tongue Cancer Lines With and Without Corresponding Mutations.

OBJECTIVES: Human papillomavirus positive (HPV+) tonsillar and base of tongue squamous cell carcinoma (TSCC/BOTSCC), the major subsites of oropharyngeal squamous cell carcinoma (OPSCC) have favorable outcome, but upon relapse, outcome is poor and new therapies needed. Since, phosphatidyl-inositol-4,5-bisphosphate 3-kinase, catalytic subunit alpha (PIK3CA) and fibroblast-growth-factor-receptor-3 (FGFR3) mutations often occur in such tumors, here, we tested targeted therapy directed to such genes in TSCC/BOTSCC cell lines. We also combined the two types of inhibitors with each other, and cisplatin or docetaxel that are used clinically. METHODS: The HPV+ CU-OP-2, -3, -20, UPCI-SCC-154, and HPV- CU-OP-17 and UT-SCC-60A cell lines were first tested for common PIK3CA/FGFR3 mutations by competitive-allele-specific TaqMan-PCR. They were then treated with the food and drug administration (FDA) approved drugs, alpelisib (BYL719) and erdafitinib (JNJ-42756493) alone and in combination with cisplatin or docetaxel. Viability, proliferation, apoptosis and cytotoxicity responses were thereafter followed by WST-1 assays and the IncuCyte S3 Live® Cell Analysis System. RESULTS: HPV+ CU-OP-2 had a pS249C-FGFR3, and like CU-OP-20, a pE545K-PIK3CA mutation, while no other lines had such mutations. Irrespectively, dose dependent responses to all PI3K/FGFR inhibitors were obtained, and upon combining the inhibitors, positive effects were observed. Cisplatin and docetaxel also induced dose dependent responses, and upon combination with the inhibitors, both positive and neutral effects were found. CONCLUSIONS: The data suggest that FDA approved drugs alpelisib and erdafitinib efficiently inhibit TSCC/BOTSCC cell line growth, especially when combined irrespective of presence of corresponding mutations and should be further explored, for use upon recurrent disease.

The value of p16 and HPV DNA in non-tonsillar, non-base of tongue oropharyngeal cancer.

BACKGROUND: Oropharyngeal squamous cell carcinoma (OPSCC) is dominated by tonsillar and tongue base carcinomas (TSCC/BOTSCC), but there are carcinomas at other sites, such as uvula/soft palate/pharyngeal wall here defined as other OPSCC. Human papillomavirus (HPV) positive TSCC/BOTSCC have favorable outcome, and the TNM-classification separates OPSCC into HPV mediated (p16INK4a overexpressing, p16+) and HPV unrelated OPSCC (p16INK4a non-overexpressing, p16-) cancer, but the prognostic role of p16+ in other OPSCC is unclear. AIMS/OBJECTIVES: This study therefore aimed to further investigate the prognostic role of p16+, presence of HPV DNA, or both combined in other OPSCC. MATERIAL AND METHODS: 195 other OPSCC, from patients diagnosed 2000-2018 were tested for p16, and/or presence of HPV DNA and the data correlated to outcome. RESULTS: Neither overall survival, nor disease free survival correlated to presence of p16+ or HPV DNA in other OPSCC. p16+ and HPV DNA presence were correlated (p < .0001), but the sensitivity of p16 as a surrogate marker for presence of HPV DNA was low (49%). CONCLUSIONS AND SIGNIFICANCE: The data suggest that p16+ (and p16+/HPV DNA) positive other OPSCC should be analyzed cautiously and possibly separately from the HPV mediated OPSCC staging group.

Targeting Fibroblast Growth Factor Receptor (FGFR) and Phosphoinositide 3-kinase (PI3K) Signaling Pathways in Medulloblastoma Cell Lines.

BACKGROUND/AIM: Medulloblastoma (MB) accounts for ~20% of pediatric malignant central nervous system tumors. Treatment strategies, including surgery, radiation therapy and/or chemotherapy, are effective, but recurrence and metastasis frequently occur. Therefore, novel therapies are required. Herein, the effects of fibroblast growth factor receptor (FGFR) and phosphoinositide 3-kinase (PI3K) inhibitors on MB cells lines were evaluated. MATERIALS AND METHODS: MB cell lines (UW228-3, DAOY, Med8a, D425, D283) were tested for sensitivity to FGFR (AZD4547) and PI3K (BEZ235 and BYL719) inhibitors by viability, cytotoxicity, apoptosis, and proliferation assays. RESULTS: Single treatments with FGFR and PI3K inhibitors decreased viability and proliferation in a dose-dependent pattern in most cell lines. Combinination of the two type of drugs, increased sensitivity, especially of the most resistant cell line UW228-3. CONCLUSION: Combination treatments with FGFR and PI3K inhibitors were superior to single treatments with FGFR and PI3K inhibitors, especially with BEZ235, for MB cell lines.

Differences in gene expression between high-grade dysplasia and invasive HPV+ and HPV- tonsillar and base of tongue cancer.

BACKGROUND: Human papillomavirus (HPV) is a causative agent for tonsillar and base of tongue squamous cell carcinoma (TSCC/BOTSCC), as well as for cervical cancer. Premalignant stages in cervical cancer have been studied extensively, while little is known about premalignant stages in TSCC/BOTSCC and the role of HPV. Here we analyzed differences in gene and protein expression between high-grade dysplasia and invasive cancer in both HPV-positive (HPV+ ) and HPV-negative (HPV- ) TSCC/BOTSCC. METHODS: High-grade dysplasia and invasive carcinoma were laser microdissected from HPV+ and HPV- TSCC/BOTSCC tumor sections. Differential gene expression was studied utilizing nanoString RNA-panels and genes of interest were validated on the protein level by immunohistochemistry. RESULTS: Forty genes in the HPV+ tumors showed significantly different expression between high-grade dysplasia and invasive cancer and 33 genes in the HPV- tumors. Five out of the nine most significant pathways showed similar increased activity in invasive cancer as compared to high-grade dysplasia in both HPV+ and HPV- tumors. Lastly, significant differences in protein expression was confirmed for SPARC, psoriasin, type I collagen and galectin-1 in both HPV+ and HPV- tumors. CONCLUSIONS: This is to our knowledge the first study disclosing differences and similarities in gene expression between dysplastic and invasive HPV+ and HPV- TSCC/BOTSCC.

Changes in Cervical Human Papillomavirus (HPV) Prevalence at a Youth Clinic in Stockholm, Sweden, a Decade After the Introduction of the HPV Vaccine.

Aim: This study aimed to follow the impact of human papillomavirus (HPV) catch-up and vaccination on the very high cervical HPV-prevalence in women at a youth clinic in central Stockholm during the period 2008-2018. Background: 2008-2010, cervical HPV-prevalence (69.5%) and HPV16 prevalence (34.7%) were high in non-vaccinated women at a youth clinic in Stockholm. 2013-2015, after the introduction of the quadrivalent-Gardasil® HPV-vaccine, HPV16 and HPV6 prevalence had decreased. Here, cervical HPV-prevalence was investigated 10 years after primary sampling. Material and Methods: 2017-2018, 178 cervical swabs, from women aged 15-23 years old, were tested for 27 HPV types by a bead-based multiplex method. HPV-prevalence data were then related to vaccination status and age and compared to HPV-prevalence in 615 samples from 2008 to 2010 and 338 samples from 2013 to 2015 from the same clinic, and to HPV types in 143 cervical cancer cases during 2003-2008 in Stockholm. Results: The proportion of vaccinated women increased from 10.7% (2008-2010) to 82.1% (2017-2018). The prevalence of all 27 HPVs, all high-risk HPVs (HR-HPVs) and the combined presence of the quadrivalent-Gardasil® types HPV16, 18, 6, and 11, was lower in vaccinated compared to unvaccinated women (67.4 vs. 93.3%, p = 0.0031, 60.1 vs. 86.7%, p = 0.0057 and 5.8 vs. 26.7%, p = 0.002, respectively). Furthermore, HPV16 prevalence in non-vaccinated women 2017-2018 was lower than that in 2008-2010 (16.7 and 34.7%, respectively, p = 0.0471) and similar trends were observed for HPV18 and 11. In both vaccinated and non-vaccinated women, the most common non-quadrivalent-Gardasil® vaccine HR-HPV types were HPV39, 51, 52, 56, and 59. Together they accounted for around 9.8% of cervical cancer cases in Stockholm during 2003-2008, and their prevalence tended to have increased during 2017-2018 compared to 2008-2010. Conclusion: Quadrivalent-Gardasil® vaccination has decreased HPV-vaccine type prevalence significantly. However, non-vaccine HR-HPV types remain high in potentially high-risk women at a youth clinic in Stockholm.

Overexpression of FGFR3 in HPV-positive Tonsillar and Base of Tongue Cancer Is Correlated to Outcome.

BACKGROUND/AIM: Human papillomavirus-positive (HPV+) tonsillar and base of tongue squamous cell carcinoma (TSCC/BOTSCC) have better outcome than corresponding HPV- cancers. To better individualize treatment, additional predictive markers are needed. Previously, we have shown that mutated fibroblast growth factor receptor 3 protein (FGFR3) was correlated to poorer prognosis and here FGFR3 expression was further analyzed. PATIENTS AND METHODS: One-hundred-fifteen HPV+TSCC/ BOTSCC biopsies were analyzed for FGFR3 by immunohistochemistry (IHC), and 109/115 were analyzed for FGFR3 mutations by Ion Proton sequencing, or by Competitive Allele-Specific Taqman PCR (CAST-PCR). Disease-free survival (DFS) was then calculated according to FGFR3 IHC expression. RESULTS: CAST-PCR was useful for detecting the three most common FGFR3 mutations. Focusing especially on the 98/115 patients with HPV+TSCC/BOTSCC and wild-type FGFR3, high FGFR3 expression correlated to significantly better 3-year DFS, p=0.043. CONCLUSION: In patients with HPV+TSCC/BOTSCC and wild-type FGFR3, overexpression of FGFR3 was correlated with better DFS.