High-risk HPV infection-associated hypermethylated genes in oropharyngeal squamous cell carcinomas

Background

HPV-positive oropharyngeal squamous cell carcinomas (OPSCCs) are sensitive to chemo-radiation therapy and have favorable survival outcomes compared with HPV-negative cancers. These tumors are usually not related to tobacco and alcohol exposure. Therefore, diagnosing HPV-positive OPSCCs for the appropriate disease management is crucial, and no suitable markers are available for detecting early malignancies in HPV-infected tissues. In this study, we attempt to find HPV-specific epigenetic biomarkers for OPSCCs.

Methods

A total of 127 surgical samples were analyzed for HPV positivity and promoter methylation of a panel of genes. HPV detection was performed by PCR detection of HPV E6 and E7 viral oncoproteins. In addition, promoter methylation of a total of 8 genes (DAPK, FHIT, RASSF1A, TIMP3, AGTR1, CSGALNACT2, GULP1 and VGF) was analyzed by quantitative-methylation specific PCR (QMSP), and their associations with HPV positivity or RB/p16 expressions were evaluated.

Results

AGTR1 and FHIT were frequently methylated in HPV-positive OPSCC samples with a good area under the curve (AUC over 0.70). In addition, these genes' promoter methylation was significantly associated with p16 positive and RB negative cases, which were the characteristics of OPSCC cases with favorable survival outcomes. Either AGTR1 or FHIT methylated cases were significantly associated with HPV-positive cancers with 92.0% sensitivity (P < 0.001). Also, they had significantly better overall survival (P = 0.047) than both unmethylated cases.

Conclusions

A combination of AGTR1 and FHIT methylation demonstrated a suitable detection marker of OPSCCs derived from the HPV-infected field, familiar with p16-positive and RB-negative phenotypes.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-10227-w.

Biological tumor markers associated with local control after primary radiotherapy in laryngeal cancer: A systematic review

BACKGROUND

The choice of treatment in laryngeal cancer is mainly based on tumor stage, post-treatment morbidity and quality of life. Biological tumor markers might also be of potential clinical relevance.

OBJECTIVE OF THE REVIEW

The aim was to systematically review the value of published biological tumor markers to predict local control in laryngeal cancer patients treated with definitive radiotherapy.

TYPE OF REVIEW

Systematic review.

SEARCH STRATEGY

PubMed, Embase, Cochrane Library.

EVALUATION METHOD

A literature search was performed using multiple terms for laryngeal cancer, radiotherapy, biological markers, detection methods and local control or survival. Studies regarding the relation between biological tumor markers and local control or survival in laryngeal cancer patients primarily treated with radiotherapy were included. Markers were clustered on biological function. Quality of all studies was assessed. Study selection, data extraction and quality assessment was performed by two independent reviewers.

RESULTS

A total of 52 studies out of 618 manuscripts, concerning 118 markers, were included. EGFR and P53 showed consistent evidence for not being predictive of local control after primary radiotherapy, whereas proliferation markers (ie high Ki-67 expression) showed some, but no consistent, evidence for being predictive of better local control. Other clusters of markers (markers involved in angiogenesis and hypoxia, apoptosis markers, cell cycle, COX-2 and DNA characteristics) showed no consistent evidence towards being predictors of local control after primary radiotherapy.

CONCLUSIONS

Cell proliferation could be of potential interest for predicting local control after primary radiotherapy in laryngeal cancer patients, whereas EGFR and p53 are not predictive in contrast to some previous analyses. Large diversity in research methods is found between studies, which results in contradictory outcomes. Future studies need to be more standardised and well described according to the REMARK criteria in order to have better insight into which biomarkers can be used as predictors of local control after primary radiotherapy.

High pATM is Associated With Poor Local Control in Supraglottic Cancer Treated With Radiotherapy

Objectives

Most early stage laryngeal squamous cell carcinomas (LSCC) are treated with radiotherapy. Discovery of new biomarkers are needed to improve prediction of outcome after radiotherapy and to identify potential targets for systemic targeted therapy. The ataxia telangiectasia mutated (ATM) gene plays a critical role in DNA damage response induced by ionizing radiation.

Methods

The prognostic value of immunohistochemical expression of pATM, pChk2, and p53 were investigated in 141 patients with T1‐T2 LSCC curatively treated with external beam radiotherapy. Uni‐ and multivariable Cox regression analyses were performed to examine the relation between expression levels of markers and local control.

Results

Local control was significantly worse in cases with high levels of pATM (HR 2.14; 95% CI, 1.08–4.24; P = .03). No significant associations with local control were found for pChk2 and p53 expression. The association of high pATM expression with poor local control was only found for supraglottic LSCC (HR 10.9; 95% CI, 1.40–84.4; P = .02).

Conclusion

Our findings suggest a potential role for ATM in response to radiotherapy in early stage supraglottic LSCC and imply ATM inhibition as a possibility to improve response to radiotherapy.

Level of Evidence

NA Laryngoscope, 130: 1954–1960, 2020

Standardised Ki-67 proliferation index assessment in early-stage laryngeal squamous cell carcinoma in relation to local control and survival after primary radiotherapy

Objectives

Ambiguous results have been reported on the predictive value of the Ki‐67 proliferation index (Ki‐67 PI) regarding local control (LC) and survival after primary radiotherapy (RT) in early‐stage laryngeal squamous cell cancer (LSCC). Small study size, heterogenic inclusion, variations in immunostaining and cut‐off values are attributing factors. Our aim was to elucidate the predictive value of the Ki‐67 PI for LC and disease‐specific survival (DSS) using a well‐defined series of T1‐T2 LSCC, standardised automatic immunostaining and digital image analysis (DIA).

Methods

A consecutive and well‐defined cohort of 208 patients with T1‐T2 LSCC treated with primary RT was selected. The Ki‐67 PI was determined using DIA. Mann‐Whitney U‐tests, logistic and Cox regression analyses were performed to assess associations between Ki‐67 PI, clinicopathological variables, LC and DSS.

Results

In multivariate Cox regression analysis, poor tumour differentiation (HR 2.20; 95% CI 1.06‐4.59, P = .04) and alcohol use (HR 2.84, 95% CI 1.20‐6.71; P = .02) were independent predictors for LC. Lymph node positivity was an independent predictor for DSS (HR 3.16, 95% CI 1.16‐8.64; P = .03). Ki‐67 PI was not associated with LC (HR 1.59; 95% CI 0.89‐2.81; P = .11) or DSS (HR 0.98; 95% CI 0.57‐1.66; P = .97). In addition, continuous Ki‐67 PI was not associated with LC (HR 2.03; 95% CI 0.37‐11.14, P = .42) or DSS (HR 0.62; 95% CI 0.05‐8.28; P = .72).

Conclusion

The Ki‐67 PI was not found to be a predictor for LC or DSS and therefore should not be incorporated in treatment‐related decision‐making for LSCC.

JAK3 Variant, Immune Signatures, DNA Methylation, and Social Determinants Linked to Survival Racial Disparities in Head and Neck Cancer Patients

To inform novel personalized medicine approaches for race and socioeconomic disparities in head and neck cancer, we examined germline and somatic mutations, immune signatures, and epigenetic alterations linked to neighborhood determinants of health in Black and non-Latino White (NLW) patients with head and neck cancer. Cox proportional hazards revealed that Black patients with squamous cell carcinoma of head and neck (HNSCC) with PAX5 (P = 0.06) and PAX1 (P = 0.017) promoter methylation had worse survival than NLW patients, after controlling for education, zipcode, and tumor-node-metastasis stage (n = 118). We also found that promoter methylation of PAX1 and PAX5 (n = 78), was correlated with neighborhood characteristics at the zip-code level (P < 0.05). Analyses also showed differences in the frequency of TP53 mutations (n = 32) and tumor-infiltrating lymphocyte (TIL) counts (n = 24), and the presence of a specific C → A germline mutation in JAK3, chr19:17954215 (protein P132T), in Black patients with HNSCC (n = 73; P < 0.05), when compared with NLW (n = 37) patients. TIL counts are associated (P = 0.035) with long-term (>5 years), when compared with short-term survival (<2 years). We show bio-social determinants of health associated with survival in Black patients with HNSCC, which together with racial differences shown in germline mutations, somatic mutations, and TIL counts, suggests that contextual factors may significantly inform precision oncology services for diverse populations.

16S rRNA amplicon sequencing identifies microbiota associated with oral cancer, human papilloma virus infection and surgical treatment

Systemic inflammatory events and localized disease, mediated by the microbiome, may be measured in saliva as head and neck squamous cell carcinoma (HNSCC) diagnostic and prognostic biomonitors. We used a 16S rRNA V3-V5 marker gene approach to compare the saliva microbiome in DNA isolated from Oropharyngeal (OPSCC), Oral Cavity Squamous Cell Carcinoma (OCSCC) patients and normal epithelium controls, to characterize the HNSCC saliva microbiota and examine their abundance before and after surgical resection.The analyses identified a predominance of Firmicutes, Proteobacteria and Bacteroidetes, with less frequent presence of Actinobacteria and Fusobacteria before surgery. At lower taxonomic levels, the most abundant genera were Streptococcus, Prevotella, Haemophilus, Lactobacillus and Veillonella, with lower numbers of Citrobacter and Neisseraceae genus Kingella. HNSCC patients had a significant loss in richness and diversity of microbiota species (p<0.05) compared to the controls. Overall, the Operational Taxonomic Units network shows that the relative abundance of OTU's within genus Streptococcus, Dialister, and Veillonella can be used to discriminate tumor from control samples (p<0.05). Tumor samples lost Neisseria, Aggregatibacter (Proteobacteria), Haemophillus (Firmicutes) and Leptotrichia (Fusobacteria). Paired taxa within family Enterobacteriaceae, together with genus Oribacterium, distinguish OCSCC samples from OPSCC and normal samples (p<0.05). Similarly, only HPV positive samples have an abundance of genus Gemellaceae and Leuconostoc (p<0.05). Longitudinal analyses of samples taken before and after surgery, revealed a reduction in the alpha diversity measure after surgery, together with an increase of this measure in patients that recurred (p<0.05). These results suggest that microbiota may be used as HNSCC diagnostic and prognostic biomonitors.

Viable tumor in salvage neck dissections in head and neck cancer: Relation with initial treatment, change of lymph node size and human papillomavirus

OBJECTIVES

To identify predictive factors for the presence of viable tumor and outcome in head and neck cancer patients who undergo therapeutic salvage neck dissections.

MATERIALS AND METHODS

Retrospective analysis of 76 salvage neck dissections after radiotherapy alone (n = 22), radiotherapy in combination with carboplatin/5-fluorouracil (n = 42) or with cetuximab (n = 12).

RESULTS

Viable tumor was detected in 41% of all neck dissections. Univariate analysis revealed initial treatment with radiotherapy without systemic therapy (OR 6.93, 95%CI: 2.28-21.07, p < .001), increased lymph node size after initial treatment compared to pretreatment CT scan (OR 20.48, 95%CI: 2.46-170.73, p = .005), more extensive neck dissections (OR 8.40, 95%CI: 2.94-23.98, p < .001), and human papillomavirus negative cancer (OR 4.22, 95%CI: 1.10-16.22, p = .036) as predictors of viable tumor. Patients with decreased or stable, but persistently enlarged lymph node size after chemoradiation had a significantly lower chance of viable tumor (OR 0.15, 95%CI: 0.05-0.41, p < .001). Disease-specific 5-year survival was 34% in case of viable tumor, and 78% when no viable tumor was found (p < .001).

CONCLUSIONS

Viable tumor in salvage neck dissections is associated with reduced survival. Radiotherapy alone, human papillomavirus negative cancer and increase in lymph node size, are associated with viable tumor in salvage neck dissections. In case of decreased or stable lymph node size after chemoradiation, watchful waiting could be considered.

Clinical outcome of salvage neck dissections in head and neck cancer in relation to initial treatment, extent of surgery and patient factors

OBJECTIVE

Salvage surgery has a higher complication rate compared to primary surgical treatment. We evaluated clinical outcome of salvage neck dissections in relation to initial treatment modality, extent of surgery and patient-related factors.

DESIGN

Single institution consecutive case series.

SETTING

Tertiary Head and Neck Cancer Centre.

PARTICIPANTS

In all, 87 patients with head and neck squamous cell carcinoma, who underwent salvage neck dissection after initial radiotherapy (n = 30), radiotherapy with carboplatin/5-fluorouracil (n = 43) or radiotherapy with cetuximab (n = 14).

MAIN OUTCOME MEASURES

Incidence of complications, disease-specific survival.

RESULTS

Complications occurred in 28% of the patients. Multivariate analysis identified extent of neck dissection as the only independent predictor of surgical complications (P = 0.010). Surgical complication rate was 16% after radiotherapy with systemic treatment, and 47% after radiotherapy alone (P = 0.171). The 5-year disease-specific survival was 55%, independent of complications, initial treatment, extent of surgery and patient-related factors.

CONCLUSION

The only predictor for surgical complications was extent of surgery. Survival was not influenced by complications.

Abstract 1533: 16S rRNA saliva analysis unveils differences in the head and neck squamous cell carcinoma microbiome before and after surgical resection

Systemic inflammatory events and localized disease, mediated by the microbiome, may be measured in saliva as head and neck squamous cell carcinoma (HNSCC) diagnostic and prognostic biomonitors. We compared the saliva microbiome in DNA isolated from 38 patients and 25 normal oral cavity epithelium controls to characterize the HNSCC microbiota before and after surgical resection.

PCR amplification of the 16S rRNA V3-V5 gene region was performed using the 357F/926R primer set prior to multiplexing on the Roche/454 GS Junior sequencing platform. Data were screened for chimeric sequences and contaminant chloroplast DNA after pre-processing. Passing sequences were characterized for diversity and taxonomic composition using QIIME and R before cross-tabulation analyses were performed.

After preprocessing 142,887 reads were obtained with an average length of 491 bp. The number of sequences per sample was rarefied at 3,487 to guarantee equal depth. Bacteroidetes, Firmicutes, and Proteobacteria dominated the microbiome in our sample set with less frequent presence of Actinobacteria and Fusobacteria members. At lower taxonomic levels, the most abundant genera observed were Streptococcus, Prevotella, Haemophilus and Veillonella with lower numbers of Citrobacter and Neisseraceae genus Kingella.

We found that 46 OTUs changed significantly in HNSCC patients (p&lt;0.05) when compared to the controls mainly due to the loss of Neisseria and Aggregatibacter (Proteobacteria), Leptotrichia (Fusobacteria) and Veilonella (Firmicutes) with an increase in some Lactobacillus (Firmicutes). Within bacteroidetes, Prevotella OTUs were found more abundant in control samples. HNSCC patients had a significant loss in richness and diversity (p&lt;0.05) compared to the controls. HPV positive samples were more diverse (higher Shannon values and richness) than HPV negative samples.

Longitudinal analyses (3 time periods) of samples taken before and after surgery revealed a reduction in the alpha diversity measure after surgery, together with an increase of this measure in patients that recurred. We also observed statistically significant differences (p&lt;0.05) at the phyla (Actinobacteria and Fusobacteria), and genus (Veillonella and Prevotella) levels. Interestingly, in one patient whose HPV status shifted from HPV positive to HPV negative after surgery, the abundance of Lactobacillus OTUs decreased, and Streptococcus (OTU 1009) increased significantly, being also associated with an HPV negative status in another patient.

We are the first to observe that OTUs and several microbial communities at different taxonomic levels discriminate HNSCC from control samples; HPV positive and HPV negative samples; and pre- vs postsurgical treatment samples. Future work will determine the correlation of microbial communities in paired tissue and saliva HNSCC samples, as well as their link to treatment response and survival.

Citation Format: Rafael E. Guerrero-Preston, Filipa Godoy-Vitorino, Herminio González, Christina Michailidi, Anne Jedlicka, Amanda Dziedzic, Rajagowthamee Thangavel, Tal Hadar, Maartje G. Noordhuis, William Westra, Wayne Koch, David Sidransky. 16S rRNA saliva analysis unveils differences in the head and neck squamous cell carcinoma microbiome before and after surgical resection. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 1533. doi:10.1158/1538-7445.AM2015-1533

Key tumor suppressor genes inactivated by "greater promoter" methylation and somatic mutations in head and neck cancer

Tumor suppressor genes (TSGs) are commonly inactivated by somatic mutation and/or promoter methylation; yet, recent high-throughput genomic studies have not identified key TSGs inactivated by both mechanisms. We pursued an integrated molecular analysis based on methylation binding domain sequencing (MBD-seq), 450K Methylation arrays, whole exome sequencing, and whole genome gene expression arrays in primary head and neck squamous cell carcinoma (HNSCC) tumors and matched uvulopalatopharyngoplasty tissue samples (UPPPs). We uncovered 186 downregulated genes harboring cancer specific promoter methylation including PAX1 and PAX5 and we identified 10 key tumor suppressor genes (GABRB3, HOXC12, PARP15, SLCO4C1, CDKN2A, PAX1, PIK3AP1, HOXC6, PLCB1, and ZIC4) inactivated by both promoter methylation and/or somatic mutation. Among the novel tumor suppressor genes discovered with dual mechanisms of inactivation, we found a high frequency of genomic and epigenomic alterations in the PAX gene family of transcription factors, which selectively impact canonical NOTCH and TP53 pathways to determine cell fate, cell survival, and genome maintenance. Our results highlight the importance of assessing TSGs at the genomic and epigenomic level to identify key pathways in HNSCC, deregulated by simultaneous promoter methylation and somatic mutations.

Genome-wide methylation profiling reveals Zinc finger protein 516 (ZNF516) and FK-506-binding protein 6 (FKBP6) promoters frequently methylated in cervical neoplasia, associated with HPV status and ethnicity in a Chilean population

Cervical cancer is a major health concern among women in Latin America due to its high incidence and mortality. Therefore, the discovery of molecular markers for cervical cancer screening and triage is imperative. The aim of this study was to use a genome wide DNA methylation approach to identify novel methylation biomarkers in cervical cancer. DNA from normal cervical mucosa and cervical cancer tissue samples from Chile was enriched with Methylated DNA Immunoprecipitation (MeDIP), hybridized to oligonucleotide methylation microarrays and analyzed with a stringent bioinformatics pipeline to identify differentially methylated regions (DMRs) as candidate biomarkers. Quantitative Methylation Specific PCR (qMSP) was used to study promoter methylation of candidate DMRs in clinical samples from two independent cohorts. HPV detection and genotyping were performed by Reverse Line Blot analysis. Bioinformatics analysis revealed GGTLA4, FKBP6, ZNF516, SAP130, and INTS1 to be differentially methylated in cancer and normal tissues in the Discovery cohort. In the Validation cohort FKBP6 promoter methylation had 73% sensitivity and 80% specificity (AUC = 0.80). ZNF516 promoter methylation was the best biomarker, with both sensitivity and specificity of 90% (AUC = 0.92), results subsequently corroborated in a Prevalence cohort. Together, ZNF516 and FKBP6 exhibited a sensitivity of 84% and specificity of 81%, when considering both cohorts. Our genome wide DNA methylation assessment approach (MeDIP-chip) successfully identified novel biomarkers that differentiate between cervical cancer and normal samples, after adjusting for age and HPV status. These biomarkers need to be further explored in case-control and prospective cohorts to validate them as cervical cancer biomarkers.

Abstract 655: Genome-wide methylation profiling and the PI3K-AKT pathway analysis associated with smoking in urothelial cell carcinoma

Urothelial Cell Carcinoma (UCC) is the second most common genitourinary malignant disease in the USA, and tobacco smoking is the major known risk factor for UCC development. Exposure to carcinogens, such as those contained in tobacco smoke, is known to directly or indirectly damage DNA, causing mutations, chromosomal deletion events and epigenetic alterations in UCC. Molecular studies have shown that chromosome 9 alterations and P53, RAS, RB and PTEN mutations are among the most frequent events in UCC. Recent studies suggested that continuous tobacco carcinogen exposure drives and enhances the selection of epigenetically altered cells in UCC, predominantly in the invasive form of the disease. However, the sequence of molecular events that lead to UCC after exposure to tobacco smoke is not well understood.

To elucidate molecular events that lead to UCC oncogenesis and progression after tobacco exposure, we developed an in vitro cellular model for smoking induced UCC. SV-40 immortalized normal HUC1 human bladder epithelial cells were continuously exposed to 0.1% cigarette smoke extract (CSE) until transformation occurred. Morphological alterations and increased cell proliferation of non-malignant urothelial cells were observed after 4 months of treatment with CSE. Anchorage-independent growth assessed by soft agar assay and increase in the migratory and invasive potential was observed in urothelial cells after 6 months of CSE treatment. By performing a PCR mRNA expression array specific to the PI3K-AKT pathway, we found 26 genes were up-regulated and 22 genes were down-regulated after 6 months of CSE exposure of HUC cells. Among the altered genes, PTEN, FOXO1, MAPK1 and PDK1 were down-regulated in the transformed cells while AKT1, AKT2, HRAS, RAC1 were up-regulated. Validation by RT-PCR and western blot analysis was then performed. Furthermore, genome-wide methylation analysis revealed MCAM, DCC and HIC1 are hypermethylated in CSE treated urothelial cells when compared to non-CSE exposed cells. The methylation status of these genes was validated using Quantitative Methylation Specific PCR (QMSP), confirming an increase in methylation of CSE treated urothelial cells compared untreated controls. Therefore, our findings suggest that a tobacco signature could emerge from distinctive patterns of genetic and epigenetic alterations and can be identified using an in vitro cellular model for the development of smoking induced cancer.

Citation Format: Enrico Munari, Mariana Brait, Cynthia LeBron, Maartje G. Noordhuis, Shahnaz Begum, Christina Michailidi, Nilda Gonzalez-Roibon, Leonel Maldonado, Tanusree Sen, Rafael Guerrero-Preston, Leslie Cope, Paola Parrella, Vito Michele Fazio, Patrick K. Ha, George Netto, David Sidransky, Mohammad O. Hoque. Genome-wide methylation profiling and the PI3K-AKT pathway analysis associated with smoking in urothelial cell carcinoma . [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 655. doi:10.1158/1538-7445.AM2013-655

Genome-wide methylation profiling and the PI3K-AKT pathway analysis associated with smoking in urothelial cell carcinoma

Urothelial cell carcinoma (UCC) is the second most common genitourinary malignant disease in the USA, and tobacco smoking is the major known risk factor for UCC development. Exposure to carcinogens, such as those contained in tobacco smoke, is known to directly or indirectly damage DNA, causing mutations, chromosomal deletion events and epigenetic alterations in UCC. Molecular studies have shown that chromosome 9 alterations and P53, RAS, RB and PTEN mutations are among the most frequent events in UCC. Recent studies suggested that continuous tobacco carcinogen exposure drives and enhances the selection of epigenetically altered cells in UCC, predominantly in the invasive form of the disease. However, the sequence of molecular events that leads to UCC after exposure to tobacco smoke is not well understood. To elucidate molecular events that lead to UCC oncogenesis and progression after tobacco exposure, we developed an in vitro cellular model for smoking-induced UCC. SV-40 immortalized normal HUC1 human bladder epithelial cells were continuously exposed to 0.1% cigarette smoke extract (CSE) until transformation occurred. Morphological alterations and increased cell proliferation of non-malignant urothelial cells were observed after 4 months (mo) of treatment with CSE. Anchorage-independent growth assessed by soft agar assay and increase in the migratory and invasive potential was observed in urothelial cells after 6 mo of CSE treatment. By performing a PCR mRNA expression array specific to the PI3K-AKT pathway, we found that 26 genes were upregulated and 22 genes were downregulated after 6 mo of CSE exposure of HUC1 cells. Among the altered genes, PTEN, FOXO1, MAPK1 and PDK1 were downregulated in the transformed cells, while AKT1, AKT2, HRAS, RAC1 were upregulated. Validation by RT-PCR and western blot analysis was then performed. Furthermore, genome-wide methylation analysis revealed MCAM, DCC and HIC1 are hypermethylated in CSE-treated urothelial cells when compared with non-CSE exposed cells. The methylation status of these genes was validated using quantitative methylation-specific PCR (QMSP), confirming an increase in methylation of CSE-treated urothelial cells compared to untreated controls. Therefore, our findings suggest that a tobacco signature could emerge from distinctive patterns of genetic and epigenetic alterations and can be identified using an in vitro cellular model for the development of smoking-induced cancer.

OGDHL is a modifier of AKT-dependent signaling and NF-κB function

Oxoglutarate dehydrogenase (OGDH) is the first and rate-limiting component of the multi-enzyme OGDH complex (OGDHC) whose malfunction is associated with neuro-degeneration. The essential role of this complex is in the degradation of glucose and glutamate and the OGDHL gene (one component of OGDHC) is down-regulated by promoter hypermethylation in many different cancer types. These properties suggest a potential growth modulating role of OGDHL in cancer; however, the molecular mechanism through which OGDHL exerts its growth modulating function has not been elucidated.

Here, we report that restoration of OGDHL expression in cervical cancer cells lacking endogenous OGDHL expression suppressed cell proliferation, invasion and soft agar colony formation in vitro. Knockdown of OGDHL expression in cervical cancer cells expressing endogenous OGDHL had the opposite effect. Forced expression of OGDHL increased the production of reactive oxygen species (ROS) leading to apoptosis through caspase 3 mediated down-regulation of the AKT signaling cascade and decreased NF-κB phosphorylation. Conversely, silencing OGDHL stimulated the signaling pathway via increased AKT phosphorylation. Moreover, the addition of caspase 3 or ROS inhibitors in the presence of OGDHL increased AKT signaling and cervical cancer cell proliferation.

Taken together, these data suggest that inactivation of OGDHL can contribute to cervical tumorigenesis via activation of the AKT signaling pathway and thus support it as an important anti-proliferative gene in cervical cancer.

Abstract 4035: Inactivation of the putative tumor suppressor gene AGTR1 by promoter hypermethylation in primary human cancer

Introduction: Primary human cancers are thought to arise from genetic and epigenetic alterations of tumor suppressor genes and oncogenes. Transcriptional and DNA copy-number studies have improved our understanding and classification of solid tumors. Recent studies have established that like mutation, methylation-mediated gene silencing often leads to tumorigenesis. The aim of this study was to comprehensively explore the “ovarian cancer methylome” and to validate the novel methylation marker AGTR1 in a large independent series of ovarian cancer samples. Patients and methods: Fifteen ovarian cancer samples and 10 normal ovarian surface epithelium brushings were hybridized to Affymetrix U133 plus 2.0 arrays. Furthermore, 3 normal ovarian and 3 isogenic (resistant and sensitive to chemotherapy) ovarian cancer cell lines, with or without treatment with a demethylating agent were hybridized to the same array. Selection of cancer specific methylated genes was based on differential expression between normal and cancer samples, with cancer samples having lower expression than normal samples, and upregulation in cancer cell lines after treatment with a demethylating agent. A number of selected genes that showed low or no expression in primary cancer tissues and re-expressed after treatment with a demethylating agent were then tested for promoter methylation by bisulfite sequencing. Quantitative methylation specific PCR (QMSP) was developed for the AGRT1 gene and tested in a total of 353 ovarian cancer, 17 ovarian cystadenoma and 16 ovarian borderline tumor samples. Results: Fourteen primary ovarian tumor DNA samples were available from the samples that were hybridized for expression array analysis. Twelve out of 14 samples were methylated for AGRT1 which is inversely correlated with expression from our array analysis. We then tested 13 normal ovarian epithelium samples and no methylation was detected in any of the samples. Validation in a large independent set of samples confirmed that ovarian cancer samples (207/353, 53%) were more frequently methylated than ovarian cystadenoma (3/17, 18%; P=0.004). Conclusion: We have identified a set of potential tumor suppressor genes by a comprehensive discovery approach to uncover the cancer methylome. Among these genes, AGTR1 methylation was identified as a potential cancer specific methylated gene that may hold promise for further studies to establish it as a biomarker. Functional studies are warranted to evaluate the biologic role of AGTR1 methylation in the carcinogenic process of solid tumors.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 4035. doi:1538-7445.AM2012-4035

The role of ATM and 53BP1 as predictive markers in cervical cancer

Treatment of advanced-stage cervical cancers with (chemo)radiation causes cytotoxicity through induction of high levels of DNA damage. Tumour cells respond to DNA damage by activation of the 'DNA damage response' (DDR), which induces DNA repair and may counteract chemoradiation efficacy. Here, we investigated DDR components as potential therapeutic targets and verified the predictive and prognostic value of DDR activation in patients with cervical cancer treated with (chemo)radiation. In a panel of cervical cancer cell lines, inactivation of ataxia telangiectasia mutated (ATM) or its substrate p53-binding protein-1 (53BP1) clearly gave rise to cell cycle defects in response to irradiation. Concordantly, clonogenic survival analysis revealed that ATM inhibition, but not 53BP1 depletion, strongly radiosensitised cervical cancer cells. In contrast, ATM inhibition did not radiosensitise non-transformed epithelial cells or non-transformed BJ fibroblasts. Interestingly, high levels of active ATM prior to irradiation were related with increased radioresistance. To test whether active ATM in tumours prior to treatment also resulted in resistance to therapy, immunohistochemistry was performed on tumour material of patients with advanced-stage cervical cancer (n = 375) treated with (chemo)radiation. High levels of phosphorylated (p-)ATM [p = 0.006, hazard ratio (HR) = 1.817] were related to poor locoregional disease-free survival. Furthermore, high levels of p-ATM predicted shorter disease-specific survival (p = 0.038, HR = 1.418). The presence of phosphorylated 53BP1 was associated with p-ATM (p = 0.001, odds ratio = 2.206) but was not related to any clinicopathological features or survival. In conclusion, both our in vitro and patient-related findings indicate a protective role for ATM in response to (chemo)radiation in cervical cancer and point at ATM inhibition as a possible means to improve the efficacy of (chemo)radiation.

Abstract 4171: The role of ATM and 53BP1 as predictive markers and therapeutic targets in advanced stage cervical cancer

Chemoradiation is the standard of care for advanced stage cervical cancer patients and induces cytotoxicity by inducing high levels of DNA breaks in the tumor. The ability of tumor cells to repair therapy-induced DNA damage may counteract the effects of chemoradiation. The pathway responsible for DNA double strand break repair is called the ‘DNA damage response’.

In vitro we observed robust radiation-induced G1 and G2 cell cycle arrests in cervical cancer cell lines, despite the expression of HPV oncogenes, which impact the DNA damage response through rapid p53 degradation. Moreover, the DNA damage checkpoint protein ATM and its substrate 53BP1 are required for proper induction of cell cycle checkpoint arrests. Yet, when long-term survival effects were measured, inhibition of ATM, but not 53BP1, strongly sensitized cervical cancer cells to irradiation. To validate the putative role of ATM and 53BP1 in advanced stage cervical cancer we investigated presence and activity of ATM as well as 53BP1 in relation to response-to-treatment in a large, well documented, series of advanced stage cervical cancer patients (n=375). We found that high levels of ATM were related to poor response to chemoradiation (P=0.013). Importantly, high phosho-ATM immunostaining, reflecting active ATM, predicted poor responses to chemoradiation even better (P=0.004). In addition, high phospho-ATM levels predicted shorter disease-specific survival (P=0.020).

Although presence of phosphorylated 53BP1 did relate to phospho-ATM (P=0.001), it was not significantly related to any clinicopathological features or survival.

Combined, our data suggest the prognostic value of ATM signaling for responses to chemoradiation and point at ATM inhibition as a potential therapeutic target to increase treatment efficacy in advanced stage cervical cancers.

Acknowledgements

This research is supported by the Dutch Cancer Society (RUG 2007-3719) and the Netherlands Organization for Scientific Research (NWO-VENI 916.76.062).

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 4171. doi:10.1158/1538-7445.AM2011-4171

Involvement of the TGF-beta and beta-catenin pathways in pelvic lymph node metastasis in early-stage cervical cancer

PURPOSE

Presence of pelvic lymph node metastases is the main prognostic factor in early-stage cervical cancer patients, primarily treated with surgery. Aim of this study was to identify cellular tumor pathways associated with pelvic lymph node metastasis in early-stage cervical cancer.

EXPERIMENTAL DESIGN

Gene expression profiles (Affymetrix U133 plus 2.0) of 20 patients with negative (N(0)) and 19 with positive lymph nodes (N(+)), were compared with gene sets that represent all 285 presently available pathway signatures. Validation immunostaining of tumors of 274 consecutive early-stage cervical cancer patients was performed for representatives of the identified pathways.

RESULTS

Analysis of 285 pathways resulted in identification of five pathways (TGF-β, NFAT, ALK, BAD, and PAR1) that were dysregulated in the N(0), and two pathways (β-catenin and Glycosphingolipid Biosynthesis Neo Lactoseries) in the N(+) group. Class comparison analysis revealed that five of 149 genes that were most significantly differentially expressed between N(0) and N(+) tumors (P < 0.001) were involved in β-catenin signaling (TCF4, CTNNAL1, CTNND1/p120, DKK3, and WNT5a). Immunohistochemical validation of two well-known cellular tumor pathways (TGF-β and β-catenin) confirmed that the TGF-β pathway (positivity of Smad4) was related to N(0) (OR: 0.20, 95% CI: 0.06-0.66) and the β-catenin pathway (p120 positivity) to N(+) (OR: 1.79, 95%CI: 1.05-3.05).

CONCLUSIONS

Our study provides new, validated insights in the molecular mechanism of lymph node metastasis in cervical cancer. Pathway analysis of the microarray expression profile suggested that the TGF-β and p120-associated noncanonical β-catenin pathways are important in pelvic lymph node metastasis in early-stage cervical cancer.

Prognostic cell biological markers in cervical cancer patients primarily treated with (chemo)radiation: a systematic review

The aim of this study was to systematically review the prognostic and predictive significance of cell biological markers in cervical cancer patients primarily treated with (chemo)radiation. A PubMed, Embase, and Cochrane literature search was performed. Studies describing a relation between a cell biological marker and survival in ≥50 cervical cancer patients primarily treated with (chemo)radiation were selected. Study quality was assessed, and studies with a quality score of 4 or lower were excluded. Cell biological markers were clustered on biological function, and the prognostic and predictive significance of these markers was described. In total, 42 studies concerning 82 cell biological markers were included in this systematic review. In addition to cyclooxygenase-2 (COX-2) and serum squamous cell carcinoma antigen (SCC-ag) levels, markers associated with poor prognosis were involved in epidermal growth factor receptor (EGFR) signaling (EGFR and C-erbB-2) and in angiogenesis and hypoxia (carbonic anhydrase 9 and hypoxia-inducible factor-1α). Epidermal growth factor receptor and C-erbB-2 were also associated with poor response to (chemo)radiation. In conclusion, EGFR signaling is associated with poor prognosis and response to therapy in cervical cancer patients primarily treated with (chemo)radiation, whereas markers involved in angiogenesis and hypoxia, COX-2, and serum SCC-ag levels are associated with a poor prognosis. Therefore, targeting these pathways in combination with chemoradiation may improve survival in advanced-stage cervical cancer patients.