Proteomic Analysis of Cancer-Associated Fibroblasts Reveals a Paracrine Role for MFAP5 in Human Oral Tongue Squamous Cell Carcinoma.

Bidirectional communication between cells and their microenvironment is crucial for both normal tissue homeostasis and tumor growth. During the development of oral tongue squamous cell carcinoma (OTSCC), cancer-associated fibroblasts (CAFs) create a supporting niche by maintaining a bidirectional crosstalk with cancer cells, mediated by classically secreted factors and various nanometer-sized vesicles, termed as extracellular vesicles (EVs). To better understand the role of CAFs within the tumor stroma and elucidate the mechanism by which secreted proteins contribute to OTSCC progression, we isolated and characterized patient-derived CAFs from resected tumors with matched adjacent tissue fibroblasts (AFs). Our strategy employed shotgun proteomics to comprehensively characterize the proteomes of these matched fibroblast populations. Our goals were to identify CAF-secreted factors (EVs and soluble) that can functionally modulate OTSCC cells in vitro and to identify novel CAF-associated biomarkers. Comprehensive proteomic analysis identified 4247 proteins, the most detailed description of a pro-tumorigenic stroma to date. We demonstrated functional effects of CAF secretomes (EVs and conditioned media) on OTSCC cell growth and migration. Comparative proteomics identified novel proteins associated with a CAF-like state. Specifically, MFAP5, a protein component of extracellular microfibrils, was enriched in CAF secretomes. Using in vitro assays, we demonstrated that MFAP5 activated OTSCC cell growth and migration via activation of MAPK and AKT pathways. Using a tissue microarray of richly annotated primary human OTSCCs, we demonstrated an association of MFAP5 expression with patient survival. In summary, our proteomics data of patient-derived stromal fibroblasts provide a useful resource for future mechanistic and biomarker studies.

Did the addition of concurrent chemotherapy to conventional radiotherapy improve survival for patients with HPV+ve and HPV-ve Oropharynx cancer? A population-based study.

BACKGROUND: In the absence of clear evidence on the efficacy of concurrent chemoradiotherapy (CRT) over conventional radiotherapy (RT) for HPV+ve and for HPV-ve oropharyngeal cancer (OPC), this study compares the treatments and outcomes from pre-CRT years to post-CRT years. METHODS: A population-based retrospective treatment-effectiveness study based on all patients with OPC treated in Ontario Canada in 1998, 1999, 2003 and 2004. Charts were reviewed, tissue samples were requested and tissue was tested for p16 or in situ hybridisation. Overall survival (OS) and disease-specific survival (DSS) were compared by treatment era and by treatment type for all 1028 patients, for 865 treated for cure and for 610 with HPV status. RESULTS: There was no improvement in OS comparing pre-CRT to post-CRT eras for the HPV+ve patients (P=0.147) or for the HPV-ve patients (P=0.362). There was no difference in OS comparing CRT to RT for the HPV+ve cohort (HR=0.948 (0.642-1.400)) or for the HPV-ve patients (HR=1.083 (0.68-1.727)). CONCLUSIONS: In these 'real-world' patients what appeared to be improvements in OS with CRT in clinical trials were confounded by HPV status in Ontario. CRT did not improve outcomes for HPV+ve or for HPV-ve patients.

Prognostic value of pretreatment circulating neutrophils, monocytes, and lymphocytes in oropharyngeal cancer stratified by human papillomavirus status.

BACKGROUND: The objective of this study was to investigate the prognostic value of the pretreatment circulating neutrophil count (CNC), circulating monocyte count (CMC), and circulating lymphocyte count (CLC) in human papillomavirus (HPV)-related (HPV+) and HPV-unrelated (HPV-) oropharyngeal cancer (OPC). METHODS: All p16-confirmed HPV+ and HPV- OPC cases treated with chemoradiotherapy from 2000 to 2010 were included. Overall survival (OS) and recurrence-free survival (RFS) were compared for high and low CNCs, CMCs, and CLCs (dichotomized by median values). A multivariate analysis (MVA) confirmed their prognostic value in HPV+ and HPV- tumors, respectively. RESULTS: Five hundred ten HPV+ OPC cases and 192 HPV- OPC cases were included. The HPV+ cohort had lower CNC and CMC values but a CLC similar to that of the HPV- patients (P < .01). The median follow-up was 4.8 years. In the HPV+ cohort, a high CNC or CMC correlated with reduced OS and RFS in comparison with a low CNC or CMC (P < .01 for all), but no difference was evident in OS (P = .30) or RFS (P = .10) with the CLC. MVA confirmed that a higher CNC or CMC independently predicted lower OS (hazard ratio [HR] for CNC, 1.14, P < .01; HR for CMC, 2.95, P < .01) and lower RFS (HR for CNC, 1.11, P < .01; HR for CMC, 3.39, P < .01), whereas a higher CLC was associated with higher RFS (HR, 0.66, P = .03) and marginally higher OS (HR, 0.80, P = .08). In the HPV- cohort, CNC, CMC, and CLC were not predictive of OS (P = .16, P = .86, and P = .14) or RFS (P = .61, P = .59, and P = .62). CONCLUSIONS: This relatively large cohort study demonstrates that a high CNC and a high CMC independently predict inferior OS and RFS, whereas a high CLC predicts better RFS and marginally better OS in HPV+ OPC patients. This association was not apparent in HPV- patients.

Potentially novel candidate biomarkers for head and neck squamous cell carcinoma identified using an integrated cell line-based discovery strategy.

Head and neck squamous cell carcinomas (HNSCC) can arise from the oral cavity, oropharynx, larynx or hypopharynx, and is the sixth leading cancer by incidence worldwide. The 5-year survival rate of HNSCC patients remains static at 40-60%. Hence, biomarkers which can improve detection of HNSCC or early recurrences should improve clinical outcome. Mass spectrometry-based proteomics methods have emerged as promising approaches for biomarker discovery. As one approach, mass-spectrometric identification of proteins shed or secreted from cancer cells can contribute to the identification of potential biomarkers for HNSCC and our understanding of tumor behavior. In the current study, mass spectrometry-based proteomic profiling was performed on the conditioned media (i.e. secretome) of head and neck cancer (HNC) cell lines (FaDu, UTSCC8 and UTSCC42a) in addition to gene expression microarrays to identify over-expressed transcripts in the HNSCC cells in comparison to a normal control cell line. This integrated data set was systematically mined using publicly available resources (Human Protein Atlas and published proteomic/transcriptomic data) to prioritize putative candidates for validation. Subsequently, quantitative real-time PCR (qRT-PCR), Western blotting, immunohistochemistry (IHC), and ELISAs were performed to verify selected markers. Our integrated analyses identified 90 putative protein biomarkers that were secreted or shed to the extracellular space and over-expressed in HNSCC cell lines, relative to controls. Subsequently, the over-expression of five markers was verified in vitro at the transcriptional and translational levels using qRT-PCR and Western blotting, respectively. IHC-based validation conducted in two independent cohorts comprising of 40 and 39 HNSCC biopsies revealed that high tumor expression of PLAU, IGFBP7, MMP14 and THBS1 were associated with inferior disease-free survival, and increased risk of disease progression or relapse. Furthermore, as demonstrated using ELISAs, circulating levels of PLAU and IGFBP7 were significantly higher in the plasma of HNSCC patients compared with healthy individuals.

Atypical clinical behavior of p16-confirmed HPV-related oropharyngeal squamous cell carcinoma treated with radical radiotherapy.

PURPOSE: To report atypical clinical behavior observed in human papillomavirus (HPV)-related oropharyngeal carcinoma (OPC) treated with radiotherapy. METHODS AND MATERIALS: A retrospective cohort study was conducted for all newly diagnosed OPC cases treated with radiotherapy on July 1, 2003 to April 30, 2009. HPV positivity was determined by p16 immunostaining in tumors. The incidence of additional malignancies and the pattern of distant metastases (DMs) were compared between the HPV-positive (HPV+) and HPV-negative (HPV-) cohorts. RESULTS: HPV status was evaluated in 318 of 613 consecutive OPC cases (52%), showing 236 HPV+ and 82 HPV- patients. Compared with HPV-, HPV+ cases were less likely to have additional malignancies (prior: 11% vs. 20%, p = 0.038; synchronous: 1% vs. 9%, p = 0.001; metachronous: 6% vs. 16%, p = 0.003). Whereas the majority (10 of 12) of HPV- additional head-and-neck (HN) mucosal malignancies were in the oral cavity, there was none (0 of 7) in the HPV+ cohort (p < 0.001). HPV+ synchronous HN second primaries (SPs) were in the supraglottis, post-cricoid, and nasopharynx; metachronous HN SPs were in the glottis, supraglottis, and ethmoid plus glottis/post-cricoid region. All SPs that could be tested were HPV+. There was no difference in DM rate (10% vs. 15%, p = 0.272), but HPV+ DMs were more likely to involve multiple organs (46% vs. 0%, p = 0.005) and unusual sites. CONCLUSIONS: This study reports atypical clinical behavior seen in HPV+ OPC, including multicentric lesions in HN mucosa and DM to multiple organs and unusual sites. The frequency of these events is low, but they may have clinical implications. The routine assessment of HPV status for all OPC is warranted.

Gene expression profiling in cervical cancer: an exploration of intratumor heterogeneity.

PURPOSE: To explore intratumor heterogeneity in gene expression profiles from patients with cervical cancer. EXPERIMENTAL DESIGN: A total of 33 biopsies were obtained from 11 patients, sampling between two and five different areas for each tumor. The extracted RNA was hybridized onto the Affymetrix U133 Plus 2.0 oligonucleotide chip. The variance of expression within a patient (W), between patients (B) and the total variance (T = W + B) were calculated for each ProbeSet, and the ratio W/T was used as a measure of intratumor heterogeneity. Gene Ontology functional analysis was done to assess the function of genes that had high W/T (top 10%) and low W/T (bottom 10%) values. RESULTS: In total, 448 ProbeSets (2.2% of the total) had W/T < 0.10, indicating low intratumor heterogeneity, and 537 ProbeSets (2.7% of the total) had W/T > 0.90, indicating high intratumor heterogeneity. In total 14,473 ProbeSets (72.4%) had higher intertumor than intratumor heterogeneity (W/T < 0.5). Genes with low intratumor heterogeneity were characterized by a statistically significant enrichment of immune-related functions (P < 0.0001). Genes with high intratumor heterogeneity were characterized by a significant tendency towards nuclear localization and nucleic acid binding (both P < 0.0001). For genes with W/T > 0.5, more than six biopsies would be required to minimize the intratumoral heterogeneity to <0.15; if W/T is 0.3 to 0.4, four biopsies are required; and for low W/T of 0.16 to 0.3, only two to three biopsies would be needed. CONCLUSION: Although the intratumor heterogeneity was low for the majority of the tested ProbeSets, for many genes, multiple biopsies are required to obtain a reliable estimate of gene expression.

p16 gene therapy: a potentially efficacious modality for nasopharyngeal carcinoma.

p16 is an important regulator of the cell cycle at the G(1) phase. Frequent aberration of p16 in nasopharyngeal carcinoma (NPC) suggests a role for this tumor suppressor gene in disease development. p16 gene transfer has been demonstrated to be effective in various human cancer models, including breast, lung, and prostate, causing cell cycle arrest, apoptosis, and tumor growth delay. We investigated the potential of adenoviral-mediated p16 therapy, in combination with ionizing radiation (RT), in two distinct NPC models. Two deltaE1 adenoviral vectors were employed: one carrying the human p16 gene (adv.p16), and the other a beta-galactosidase reporter gene (adv.beta-gal), both driven by the cytomegalovirus (CMV) promoter. Two NPC cell lines with differential endogenous p16 expression, CNE-1 (low) and CNE-2Z (high), were evaluated for protein expression, cytotoxicity, cell cycle analysis, apoptosis, and senescence. The CNE-1 cells were exquisitely sensitive to adv.p16, with 0.1% survival level after gene therapy [25 plaque-forming unit (pfu)/cell], which further decreased to 0.01% with the addition of RT (2 Gy). This reduction in survival was effected through necrosis, G1 arrest, and senescence. In contrast, CNE-2Z cells were resistant to adv.p16 gene transfer, with 75% surviving at an equivalent viral dose. This differential sensitivity was recapitulated in vivo in that adv.p16-treated CNE-1 cells formed no tumors in severe-combined-immunodeficiency (SCID) mice, followed for over 100 days. In contrast, tumor formation was detected 40 days after implantation of adv.p16-treated CNE-2Z cells. In conclusion, adv.p16 gene transfer appears to be highly effective against NPC that lack functional p16, which is the situation in the majority of NPC patients.