Identification of acquired Notch3 dependency in metastatic Head and Neck Cancer

During cancer development, tumor cells acquire changes that enable them to invade surrounding tissues and seed metastasis at distant sites. These changes contribute to the aggressiveness of metastatic cancer and interfere with success of therapy. Our comprehensive analysis of "matched" pairs of HNSCC lines derived from primary tumors and corresponding metastatic sites identified several components of Notch3 signaling that are differentially expressed and/or altered in metastatic lines and confer a dependency on this pathway. These components were also shown to be differentially expressed between early and late stages of tumors in a TMA constructed from over 200 HNSCC patients. Finally, we show that suppression of Notch3 improves survival in mice in both subcutaneous and orthotopic models of metastatic HNSCC. Novel treatments targeting components of this pathway may prove effective in targeting metastatic HNSCC cells alone or in combination with conventional therapies.

Abstract 978: The potential role of microbiome in metastatic HNSCC

HNSCC is 6th most common malignancy in the world. Most of HNSCC patients present with metastatic disease for which the survival rates for which remain low. Hypoxia serves as a bad prognostic factor in HNSCC correlating with worse survival and resistance to radiotherapy. We aimed to discover novel targets in metastatic HNSCC utilizing a unique collection of matched sets of cell lines derived from primary tumors and their respective metastatic sites. We carried out expression profiling across the lines to reveal potential common changes in gene expression between the cells derived from primary and metastatic sites in each patient as well as between normoxia and hypoxia. This analysis revealed significant changes in gene expression between the described conditions. Interestingly, beta defensin 2 was one of the genes that came up as overexpressed in metastasis as well as in cells cultured in hypoxia. Beta defensins are small cationic peptides that belong to the innate immune system and exhibit anti-microbial and anti-viral activities. Few studies reported their abnormal expression patterns in various cancers including HNSCC. While various novel anti-cancer therapies are currently being developed, early diagnosis remains one of the biggest challenges in cancer research. A discovery of soluble serum factors that can reliably detect the presence of primary or metastatic disease would serve as an extremely valuable tool in defining diagnosis and prognosis, predicting the response to treatment, and monitoring disease progression. We hypothesized the beta defensin 2 can serve as a serum biomarker of hypoxia and metastasis in HNSCC patients. Utilizing a commercial ELISA kit developed to detect and quantify levels of beta-defensin in human sera, we demonstrated that media collected from cell lines derived from metastases contained higher levels of beta-defensin compared to the cell lines derived from the primary tumors. Moreover, sera from HNSCC patients showed higher levels of beta defensin compared to the normal controls. As a next step we tested sera samples from 40 HNSCC patients out of which 20 had lymph node metastasis and 20 did not. While these data are still under analysis, preliminary results suggest that higher concentrations of beta-defensin correlate with the presence of lymph node metastasis in HNSCC patients. Utilizing 2 large chemical libraries that together contain about 4000 FDA approved drugs we performed high through put screening of the HNSCC lines described above in order to discover new drugs targeting head and neck cancer including drugs that target selectively metastatic cells compared to their primary tumor counterparts. Interestingly, many of the metastasis-specific drugs were antibiotics. Together with the findings described above, this data clearly suggests a connection between patient microbiome and the metastatic process in HNSCC.

Citation Format: Maria Kondratyev, Aleksandra Pesic, Anna Dvorkin-Sheva, Marianne Koritzinsky, Bradly G. Wouters. The potential role of microbiome in metastatic HNSCC [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 978.

Repurposing Itraconazole and Hydroxychloroquine to Target Lysosomal Homeostasis in Epithelial Ovarian Cancer

Drug repurposing is an attractive option for oncology drug development. Itraconazole is an antifungal ergosterol synthesis inhibitor that has pleiotropic actions including cholesterol antagonism, inhibition of Hedgehog and mTOR pathways. We tested a panel of 28 epithelial ovarian cancer (EOC) cell lines with itraconazole to define its spectrum of activity. To identify synthetic lethality in combination with itraconazole, a whole-genome drop-out genome-scale clustered regularly interspaced short palindromic repeats sensitivity screen in two cell lines (TOV1946 and OVCAR5) was performed. On this basis, we conducted a phase I dose-escalation study assessing the combination of itraconazole and hydroxychloroquine in patients with platinum refractory EOC (NCT03081702). We identified a wide spectrum of sensitivity to itraconazole across the EOC cell lines. Pathway analysis showed significant involvement of lysosomal compartments, the trans-golgi network and late endosomes/lysosomes; similar pathways are phenocopied by the autophagy inhibitor, chloroquine. We then demonstrated that the combination of itraconazole and chloroquine displayed Bliss defined synergy in EOC cancer cell lines. Furthermore, there was an association of cytotoxic synergy with the ability to induce functional lysosome dysfunction, by chloroquine. Within the clinical trial, 11 patients received at least one cycle of itraconazole and hydroxychloroquine. Treatment was safe and feasible with the recommended phase II dose of 300 and 600 mg twice daily, respectively. No objective responses were detected. Pharmacodynamic measurements on serial biopsies demonstrated limited pharmacodynamic impact. In vitro, itraconazole and chloroquine have synergistic activity and exert a potent antitumor effect by affecting lysosomal function. The drug combination had no clinical antitumor activity in dose escalation.

Significance

The combination of the antifungal drug itraconazole with antimalarial drug hydroxychloroquine leads to a cytotoxic lysosomal dysfunction, supporting the rational for further research on lysosomal targeting in ovarian cancer.

Abstract 2311: Identification of therapeutic targets in HNSCC

HNSCC is 6th most common malignancy in the world. Despite advances in diagnosis and treatment, the survival rates remain low due in large part to metastatic disease. The underlying biology associated with metastatic disease and poor outcome in HNSCC remains unclear. Importantly, metastatic cells acquire new properties that permit them to invade surrounding tissues and seed metastasis at distant sites. While these acquired properties contribute to aggressiveness of metastatic cancer, they can be exploited to target metastatic cells selectively, sparing toxicity in normal tissues. We used functional genomic technologies to identify new therapeutic targets for advanced disease in HNSCC. These targets were identified by conducting whole genome shRNA screens in matched sets of cell lines derived from primary HNSCC tumors and their respective metastatic sites/recurrences. Since hypoxia is an important attribute of aggressive and therapy resistant subpopulations of HNSCC tumor cells, we also aimed to identify genes that became essential when cells are exposed to hypoxia. To complement the data from the functional screens and to further characterize our cell line collection, we utilized several high through put approaches including mutational analysis, proteomics and gene expression profiling. Moreover, we performed chemical screens using libraries of over 4000 FDA approved drugs with the aim to combine our functional genomic data with the results from the drug screens to discover drug/gene “hit” combinations that would provide a basis for development of novel anti-cancer therapies.While HNSCC derived cell lines represent a valuable tool to study this disease, their biology might not always accurately represent the biology of the tumors they were derived from. Therefore, we looked at the expression of the components of several key pathways that we discovered using the in vitro characterization in a patient material from over HNSCC surgical samples constructed into a TMA. Five of the hits belonged to the Notch signalling pathway and 4 others came from the proteomic analysis as they showed higher levels of surface expression in metastatic cells and/or under hypoxic conditions. Interestingly, higher proportion of patients with late stages of HNSCC belonged to the high Jag2 and Hey1 populations as compared to patients with low stages of HNSCC that mostly expressed low or intermediate levels of these proteins. This data is in line with our observations that Jag2 and Hey1 expression is elevated in cells derived from metastatic sites and is low in cells derived from primary tumors. Proportion of cells with high CD66 and TRAIL proteins was also higher among the late stage tumors suggesting that these biomarkers are of interest for further investigation. We discovered several molecular pathways that are important in metastatic/hypoxic HNSCC. We are investigating our ability to target these pathways using FDA approved drugs in order to achieve durable cures.

Citation Format: Maria Kondratyev, Aleksandra Pesic, Anna Dvorkin-Sheva, Troy Ketela, Natalie Stickle, Laurie Aiiles, Reidar Grenman, Marianne Koritzinsky, Brad Wouters. Identification of therapeutic targets in HNSCC [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2311.

Emergence of Enzalutamide Resistance in Prostate Cancer is Associated with BCL-2 and IKKB Dependencies

PURPOSE

Although enzalutamide (ENZ) has been widely used to treat de novo or castration-resistant metastatic prostate cancer, resistance develops and disease progression is ultimately inevitable. There are currently no approved targeted drugs to specifically delay or overcome ENZ resistance.

EXPERIMENTAL DESIGN

We selected several ENZ-resistant cell lines that replicated clinical characteristics of the majority of patients with ENZ-resistant disease. A high-throughput pharmacologic screen was utilized to identify compounds with greater cytotoxic effect for ENZ-resistant cell lines, compared with parental ENZ-sensitive cells. We validated the potential hits in vitro and in vivo, and used knockdown and overexpression assays to study the dependencies in ENZ-resistant prostate cancer.

RESULTS

ABT199 (BCL-2 inhibitor) and IMD0354 (IKKB inhibitor) were identified as potent and selective inhibitors of cell viability in ENZ-resistant cell lines in vitro and in vivo which were further validated using loss-of-function assays of BCL-2 and IKKB. Notably, we observed that overexpression of BCL-2 and IKKB in ENZ-sensitive cell lines was sufficient for the emergence of ENZ resistance. In addition, we confirmed that BCL-2 or IKKB inhibitors suppressed the development of ENZ resistance in xenografts. However, validation of both BCL-2 and IKKB in matched castration-sensitive/resistant clinical samples showed that, concurrent with the development of ENZ/abiraterone resistance in patients, only the protein levels of IKKB were increased.

CONCLUSIONS

Our findings identify BCL-2 and IKKB dependencies in clinically relevant ENZ-resistant prostate cancer cells in vitro and in vivo, but indicate that IKKB upregulation appears to have greater relevance to the progression of human castrate-resistant prostate cancer.

Abstract 507: Repurposing of FDA approved drugs for treatment of metastatic HNSCC

HNSCC is 6th most common malignancy in the world. Despite advances in diagnosis and treatment, the survival rates remain low due in large part to metastatic disease. The underlying biology associated with metastatic disease and poor outcome in HNSCC remains unclear. Importantly, metastatic cells acquire new properties that permit them to invade surrounding tissues and seed metastasis at distant sites. While these acquired properties contribute to aggressiveness of metastatic cancer and interfere with success of therapies, they can also potentially be exploited to target metastatic cells selectively, sparing toxicity in normal tissues. We used functional genomic technologies to identify new potential therapeutic targets for advanced disease in HNSCC. These targets were identified by conducting whole genome shRNA screens in matched sets of cell lines derived from primary HNSCC tumors and their respective metastatic sites or recurrences.

While extensive efforts are being made by both industry and academia to develop novel anti-cancer drugs, this process is still very slow and expensive. Drug repurposing is becoming increasingly popular due to a reduced risk to patients and lower costs of drug development compared to “de novo” discovery. We utilized 2 large chemical libraries (Selleck and Prestwick) that together contain about 4000 drugs approved by FDA and similar agencies worldwide. The libraries were screened against the HNSCC lines described above in order to discover new drugs targeting head and neck cancer including drugs that target selectively metastatic cells compared to their primary tumor counterparts. We accomplished screening of 30 HNSCC lines for all of which we have also obtained the functional genomic, mutational and gene expression data. We aim to combine our functional genomic data with the results from the drug screens to discover drug/gene “hit” combinations that would provide a basis for development of novel anti-cancer therapies. For this purpose, we are looking at correlations between the drugs and the shRNAs that have similar pattern of effects across the 30 cell lines. To complement the functional screens data, we performed targeted sequencing of the most commonly altered genes in HNSCC as reported by the TCGA. This data will help understand which pathways are affected by the drugs we select to investigate.

Out of the 30 lines, we have 13 sets of “matched” lines that belong to the same patients, coming from primary tumors, metastatic sites or recurrences. As a first step of the analysis, we looked at drugs that affected cells derived from metastases but not those from the respective primary tumors. Interestingly, many of the metastasis-specific drugs were antibiotics. We selected 10 of the drugs for further validation; dose response-based viability assays and growth curves experiments confirmed that 5 of the drugs were selectively affecting survival and proliferation of the metastatic cell lines; the mechanism of this effect are currently being investigated.

Citation Format: Maria Kondratyev, Aleksandra Pesic, Anna Dvorkin-Sheva, Troy Ketela, Jason Moffat, Marianne Koritzinsky, Brad Wouters. Repurposing of FDA approved drugs for treatment of metastatic HNSCC [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 507.

Abstract 3401: Targeting lysosomal homeostasis in ovarian cancer through drug repurposing

Background: Drug repurposing has become increasingly attractive as it avoids the long processes and costs associated with drug discovery. Itraconazole (Itra) is a broad-spectrum anti-fungal agent which has an established broad spectrum of activity in human cell lines including cholesterol antagonism and inhibition of Hedgehog and mTOR pathways. Many in vitro, in vivo and clinical studies have suggested anti-proliferative activity both alone and in combination with other chemotherapeutic agents, in particular in ovarian cancer. This study is aimed at supporting the therapeutic potential of Itra and discovering and repurposing new drugs that can increase Itra anticancer activity as well as identifying new targets in the treatment of ovarian cancer.

Methods: We tested a panel of 32 ovarian cancer cell lines with different doses of Itra and identified a subset of cells which showed significant sensitivity to the drug. To identify genetic vulnerabilities and find new therapeutic targets to combine with Itra, we performed a whole genome sensitivity CRISPR screen in 2 cell lines (TOV1946 and OVCAR5) treated with non-toxic (IC10) concentrations of Itra.

Results: Pathway analysis on the top hits from both the screens showed a significant involvement of lysosomal compartments, and in particular dynamics between trans Golgi network and late endosomes/lysosomes, pathways that are affected by the autophagy inhibitor Chloroquine (CQ). We subsequently demonstrated that the combination of Itra and CQ had a synergistic effect in many ovarian cancer cell lines, even in those resistant to Itra. Further, genetic and pharmacological manipulation of autophagy indicated that upstream inhibition of autophagy is not a key mediator of the Itra/CQ mechanism of action. However, combination of Itra with other lysosomotropic agents (Concanamycin A, Bafilomycin A and Tamoxifen) displayed overlapping activity with Itra/CQ, supporting the lysosomal involvement in sensitizing cells to Itra resulted from the CRISPR screens. Analysis of lysosomal pattern and function showed a combined effect of Itra and CQ in targeting lysosomes and neutralizing their activity.

Conclusion: We identified two FDA approved drugs – CQ and Tamoxifen - that can be used in combination with Itra and exert a potent anti-tumor effect in ovarian cancer by affecting lyosomal function and suggesting a likely dependency of these cells on lysosomal biology. Further studies are in progress.

Citation Format: Stefano Marastoni, Aleksandra Pesic, Sree Narayanan Nair, Zhu Juan Li, Ali Madani, Benjamin Haibe-Kains, Bradly G. Wouters, Anthony Joshua. Targeting lysosomal homeostasis in ovarian cancer through drug repurposing [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 3401.

Home-based HPV self-sampling assisted by a cloud-based electronic data system: Lessons learnt from a pilot community cervical cancer screening campaign in rural Ethiopia

Primary HPV testing and triage of HPV-positive women is an effective cervical cancer screening strategy. Such a multi-visit screening algorithm is also promising for community-based screening in resource-poor communities, provided a robust tracking system is in place.

A cervical cancer screening campaign was conducted in a rural community in Ethiopia. All women aged 25–65 years were offered genital self-sampling using the Evalyn Brush®. Samples were HPV-DNA-tested at a central laboratory. Key indicators were captured on tablet computers and linked by a cloud-based information system. HPV-positive women were examined at the local clinic using portable colposcopy, p16/Ki-67 dual stain cytology and biopsy examination. CIN2+ women were referred for LEEP to the referral hospital.

Of 749 enumerated age-eligible women 634 (85%, (95% CI 82–88)) consented to screening, 429 samples were adequate for HPV testing, giving a total testing coverage of 57% (95% CI 53–62). The hrHPV prevalence was 14% (95% CI 5–22), 72% (95% CI 60–84) attended the clinic for a triage examination. Home-based HPV-DNA self-sampling and clinic-based triage assisted by cloud-based information technology is feasible in rural Ethiopia. Key components of such strategy are broad community awareness, high competency of community workers, and establishment of an adequate self-sampling and HPV-DNA testing platform.

Abstract B10: Antibacterial defense and metastatic progression—lessons from head and neck cancer

HNSCC is the 6th most common malignancy in the world. The prognosis is favorable during early stages; however, the disease is rarely diagnosed early due to the lack of symptoms. Most HNSCC patients present with metastatic disease for which the survival rates remain low. Hypoxia serves as a bad prognostic factor in HNSCC correlating with worse survival and resistance to radiotherapy. We aimed to discover novel targets in metastatic HNSCC utilizing a unique collection of matched sets of cell lines derived from primary tumors and their respective metastatic sites. We carried out expression profiling across the lines to reveal potential common changes in gene expression between the cells derived from primary and metastatic sites in each patient as well as between normoxia and hypoxia. This analysis revealed significant changes in gene expression between the described conditions. Interestingly, beta defensin 2 was one of the genes that came up as overexpressed in metastasis as well as in cells cultured in hypoxia. Beta defensins are small cationic peptides that belong to the innate immune system and exhibit antimicrobial and antiviral activities. Few studies reported their abnormal expression patterns in various cancers including HNSCC. While various novel anticancer therapies are currently being developed, early diagnosis remains one of the biggest challenges in cancer research. A discovery of soluble serum factors that can reliably detect the presence of primary or metastatic disease would serve as an extremely valuable tool in defining diagnosis and prognosis, predicting the response to treatment, and monitoring disease progression. We hypothesized the beta defensin 2 can serve as a serum biomarker of hypoxia and metastasis in HNSCC patients. Utilizing a commercial ELISA kit developed to detect and quantify levels of beta-defensin in human sera, we demonstrated that media collected from cell lines derived from metastases contained higher levels of beta-defensin compared to the cell lines derived from the primary tumors. Moreover, sera from HNSCC patients showed higher levels of beta defensin compared to the normal controls. As a next step, we tested sera samples from 40 HNSCC patients, of whom 20 had lymph node metastasis and 20 did not. While these data are still under analysis, preliminary results suggest that higher concentrations of beta-defensin correlate with the presence of lymph node metastasis in HNSCC patients. Utilizing two large chemical libraries that together contain about 4,000 FDA-approved drugs, we performed high-throughput screening of the HNSCC lines described above in order to discover new drugs targeting head and neck cancer, including drugs that target selectively metastatic cells compared to their primary tumor counterparts. Interestingly, many of the metastasis-specific drugs were antibiotics. Together with the findings described above, these data clearly suggest a connection between patient microbiome and the metastatic process in HNSCC.

Citation Format: Maria Kondratyev, Aleksandra Pesic, Carl Virtanen, Marianne Koritzinsky, Brad Wouters. Antibacterial defense and metastatic progression—lessons from head and neck cancer [abstract]. In: Proceedings of the AACR Special Conference on the Microbiome, Viruses, and Cancer; 2020 Feb 21-24; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2020;80(8 Suppl):Abstract nr B10.

Clinical performance of the HPV DNA Array genotyping assay in detection of CIN2+ lesions with BS GP5+/6+ MPG Luminex tested cervical samples

Human papillomavirus (HPV) detection is used for screening of cervical cancer and genotype-specific persistence has shown to be mandatory for dysplasia development. Aim of this study was to evaluate the clinical performance of HPV DNA Array for cervical intraepithelial neoplasia 2+ (CIN2+)  lesion detection. HPV DNA Array is a polymerase chain reaction-based assay that targets E1 sequences of 29 HPV types (6, 11, 16, 18, 26, 31, 33, 35, 39, 40, 42, 44, 45, 51, 52, 53, 54, 56, 58, 59, 66, 67, 68, 69, 70, 73, 82, 85, and 97). The clinical evaluation was performed against the reference assay, BS-GP5+/6+ multiplex genotyping (MPG)-Luminex, with 600 cervical smear samples of a referral population. HPV DNA Array detected CIN2+  lesions with a sensitivity of 90.2%, identical to that of MPG-Luminex. Detection of CIN3+  lesions was with a sensitivity of 90.3%, as compared with 88.7% of MPG-Luminex. It demonstrated very good agreement for HPV detection, irrespective of type, of 91.5% (κ  =  0.832). HPV DNA Array is a simple and robust assay, with a short protocol of 4 hours hands-on time and automated readout by ELISpot AiDot software. It permits testing of up to 96 samples in one run and may be considered for use in organized screening programs and low resource settings.

Analytical Evaluation of the Human Papillomavirus HPV DNA Array E1-Based Genotyping Assay

BACKGROUND

Cervical cancer is caused by a persistent infection of human papillomavirus (HPV). Therefore, tests which detect the carcinogenic virus can be used for cervical cancer screening.

OBJECTIVE

This is the first evaluation of the HPV DNA Array (AID Diagnostika, Strassberg, Germany), an E1-based genotyping polymerase chain reaction (PCR) test for identification of 29 HPV types (6, 11, 16, 18, 26, 31, 33, 35, 39, 40, 42, 44, 45, 51, 52, 53, 54, 56, 58, 59, 66, 67, 68, 69, 70, 73, 82, 85, and 97).

METHODS

Analytical performance of the assay was assessed with cervical cancer cell lines with known HPV status, and preselected clinical cervical scrapings genotyped by multiplexed genotyping (MPG) with a Luminex readout (validated in-house assay). Intra- and inter-laboratory reproducibility experiments were performed to ensure the reliability of the assay.

RESULTS

HPV DNA Array identified the intrinsic HPV genotype in all cervical cancer cell lines and demonstrated a high sensitivity for HPV16 probe (1 cell per PCR reaction), as well as HPV18 and 45 probes (100 cells per PCR reaction). When compared with MPG, HPV DNA Array showed a good agreement of 92.2% for HPV detection irrespective of type (κ = 0.601), and demonstrated high agreement for HPV16 (80.7%, κ = 0.836) and HPV18 (86.7%, κ = 0.925). Furthermore, high intra-/inter-laboratory reproducibility was observed (90.9-100%).

CONCLUSION

HPV DNA Array showed high sensitivity for correct HPV genotype detection in experimental and clinical samples with a good correlation to the reference test. Since HPV DNA Array is based on a simple multiplexed PCR followed by reverse hybridization in a 96-well format and automated visual readout by AID ELISpot reader, it is capable of high throughput in a time-effective manner. HPV DNA Array could be considered for extended HPV genotyping of cervical smears.

Abstract 3054: Cell surface targets in head and neck cancer

HNSCC is 6th most common malignancy in the world. Despite advances in diagnosis and treatment, the survival rates remain low due in large part to metastatic disease. The underlying biology associated with metastatic disease and poor outcome in HNSCC remains unclear. Importantly, metastatic cells acquire new properties that permit them to invade surrounding tissues and seed metastasis at distant sites. While these acquired properties contribute to aggressiveness of metastatic cancer and interfere with success of therapies, they can also potentially be exploited to target metastatic cells selectively, sparing toxicity in normal tissues. We used functional genomic technologies to identify new potential therapeutic targets for advanced disease in HNSCC. These targets were identified by conducting whole genome shRNA screens in matched sets of cell lines derived from primary tumors and their respective metastatic sites, with the goal of identifying genes that become essential for cell survival only following metastasis. Since hypoxia is an important attribute of aggressive and therapy resistant subpopulations of HNSCC tumor cells, we also aimed to identify genes that became essential when cells are exposed to hypoxia. We are particularly interested in the identification of contextual synthetic lethal oncogenes expressed on the cell surface, as those are easily targetable by therapeutic antibodies. To identify these targets, we performed high-throughput flow cytometry screening that enables evaluation of 370 validated cell surface antibodies. Cell surface targets differentially expressed in metastatic lines included CECAM and CCR6 that were previously reported to be implicated in metastasis and tumor progression as well as Thy1, a known marker of stem cells involved in regulation of cell adhesion. Cell surface targets induced under hypoxic conditions across the cell lines included CA9, an enzyme that is known to regulate pH in hypoxic cells and be associated with tumor progression, as well as CD338, CD264 and CD312, that were previously associated with stemness in a few models of cancer. Interestingly, the described proteins were also found to be differentially essential in the shRNA screens, highlighting their functional importance in tumor progression and hypoxia survival. We are currently investigating the role of these proteins in HNSCC metastasis utilizing our unique collection of matched pairs of HNSCC lines from multiple patients. Moreover, we are utilizing our pipeline of patient derived HNSCC xenografts to test the effect of knocking down the described genes in patient tumors. We are also testing the expression of selected hits in histological sections of patient tumorsthe 400-patient TMA by immunohistochemistry looking for correlation with tumor grade, aggressiveness, levels of hypoxia as well as presence/absence of metastasis in the patient.

Citation Format: Maria Kondratyev, Aleksandra Pesic, Azin Sayad, Troy Ketela, Natalie Stickle, Carl Virtanen, Jason Moffat, Laurie Ailles, Marianne Koritzinsky, Brad Wouters. Cell surface targets in head and neck cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3054.

Characterization of Human Papillomavirus prevalence and risk factors to guide cervical cancer screening in the North Tongu District, Ghana

INTRODUCTION

This population-based study aimed to fill the knowledge gap on Human Papillomavirus (HPV) prevalence and associated sociodemographic risk factors of the general population in the North Tongu District, Ghana. These results are needed to guide cervical cancer prevention efforts, as the leading type of female cancers.

METHODS

A cross-sectional study including 2002 women in the North Tongu District, Ghana investigated HPV prevalence and associated sociodemographic risk factors. Women were recruited by geographical distribution through the local community-based health system and samples collected using a self-sampling device. For HPV genotyping BSGP5+/6+-PCR with Luminex-MPG readout was used. Multivariate logistic regression analyzed sociodemographic risk factors for HPV positivity.

RESULTS

Of 2002 self-collected samples, 1943 were eligible, contained sufficient DNA and provided valid HPV genotyping results. Prevalence of single high risk HPV types was 32.3% and of multiple high risk types 9.7%. The five most common detected HPV types were HPV16 (7.4%; 95%CI: 6.3-8.7), HPV52 (7.2%; 95%CI: 6.1-8.5), HPV35 (4.8%; 95%CI: 3.9-5.8), HPV59 (4.7%; 95%CI: 3.8-5.8), HPV56 (3.9%; 95%CI: 3.1-4.8). Highest prevalence was observed among women aged 18-24 years, while age 25-54 years was inversely associated with high risk HPV positivity in multivariate analysis. Sociodemographic risk factors identified were i) having any sexual partner, ii) more partners increased the odds for high risk HPV positivity, iii) independently from this marital status, in particular not being married.

DISCUSSION & CONCLUSION

Most importantly, the high risk HPV prevalence detected from this study is higher than estimates reported for Western Africa. This needs be considered, when deciding on the cervical cancer screening algorithms introduced on a wider scale. Follow-up and triage, depending on the methods chosen, can easily overburden the health system. Self-sampling worked well and provided adequate samples for HPV-based screening. Women with increasing number of sexual partners and not being married were found to have higher odds of being high risk HPV positive, therefore could be a higher prioritized screening target group.

Abstract 407: Novel targets in metastatic HNSCC

Head and neck carcinoma (HNSCC) is 6th most common malignancy in the world. Despite advances in diagnosis and treatment, the survival rates remain low due in large part to metastatic disease. The underlying biology associated with metastatic disease and poor outcome in HNSCC remains unclear. Importantly, metastatic cells acquire new properties that permit them to invade surrounding tissues and seed metastasis at distant sites. While these acquired properties contribute to aggressiveness of metastatic cancer and interfere with success of therapies, they can also potentially be exploited to target metastatic cells selectively, sparing toxicity in normal tissues. The idea behind this selective targeting is based on discovering molecular pathways that became essential in metastatic cells, and then exploiting this vulnerability through targeted agents. We used functional genomic technologies to identify new potential therapeutic targets for advanced disease in HNSCC. These targets were identified by conducting whole genome shRNA screens in matched sets of cell lines derived from primary tumors and their respective metastatic sites, with the goal of identifying genes that become essential for cell survival only following metastasis. Since hypoxia is an important attribute of aggressive and therapy resistant subpopulations of HNSCC tumor cells, we also aimed to identify genes that became essential when cells are exposed to hypoxia. To complement the functional screens data, we performed targeted sequencing of the most commonly altered genes in HNSCC as reported by the TCGA profiled gene expression in the HNSCC cell lines cultured under normoxia and hypoxia using Illumina microarrays. These analyses led to the discovery of genes that are differentially essential in metastatic cells as well as in cells exposed to hypoxic conditions. Utilizing CRISPR technology, we assembled a library of guide RNAs targeting the discovered hits and are currently validating the top identified genes using both in vitro and in vivo systems. To validate hits that are essential in metastatic cells in vivo, we engineered selected “matched” pairs of HNSCC cell lines to express CAS9 protein upon induction with doxycycline. The cells are then transduced with the library of guides and injected subcutaneously into mice; tumors from control and doxycycline treated animals are compared. The difference in genes that are essential for growth of tumors seeded by primary tumor derived and metastasis derived HNSCC cell lines is then assessed in a quantitative manner.

Citation Format: Maria Kondratyev, Aleksandra Pesic, Troy Ketela, Azin Sayad, Stephano Marastoni, Jason Mofat, Carl Virtanen, Natalie Stickle, Reider Grenman, Brad Wouters. Novel targets in metastatic HNSCC [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 407.

Abstract 3020: Novel therapeutic targets in head and neck cancer

HNSCC is 6th most common malignancy in the world. Despite advances in diagnosis and treatment, the survival rates remain low due to frequent recurrences the biology of which remains unclear. Using functional genomic technologies, we identified new therapeutic targets for metastatic disease in HNSCC. Whole genome shRNA screens were conducted in matched sets of cell lines derived from primary tumors and respective metastatic sites, identifying genes essential for cell survival only following metastasis. To test if knockdown of selected targets inhibits metastasis in a therapeutic setting, we established orthotropic model of HNSCC that metastasize to lymph nodes in the mouse. Components of Notch pathway were identified as essential for survival of cells derived from metastatic sites. Whole exome sequencing identified a novel mutation in one of the EGF domains of Notch3 that was acquired only in the metastatic line. Utilizing CRISPR methodology, we established that “fixing” the mutation results in reversal of metastatic phenotype of the cells, making them Notch independent similar to their primary tumor counterparts. Mutations in EGF domains have been reported to influence interaction with specific ligands, dictating which ligand can activate Notch signaling. Our data indicate that a distinct set of target genes is induced upon interaction between Notch3 and Jag2 ligand. Furthermore, our results indicate that suppression of Notch3 improves survival in mice bearing orthotropic tumors derived from the metastatic HNSCC lines. Overall, our data demonstrate that metastatic cells from head and neck tumors acquire dependency on Notch3 signaling. Novel treatments targeting components of this pathway may prove effective in targeting metastatic cells alone or in combination with conventional therapies.

Citation Format: Maria Kondratyev, Aleksandra Pesic, Troy Ketela, Azin Sayad, Stephano Marastoni, Carl Virtanen, Laurie Ailles, Soroush Samadian, Mikhail Bashkurov, Marianne Koritzinsky, Brad Wouters. Novel therapeutic targets in head and neck cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 3020. doi:10.1158/1538-7445.AM2017-3020

Patient-reported outcomes (PRO) focused on adverse events (PRO-AEs) in adjuvant and metastatic breast cancer: clinical and translational implications

PURPOSE

The capture of adequate treatment outcomes and quality of life (QOL) of advanced breast cancer patients in clinical routine represents a great challenge. Patient-reported outcomes (PROs) are data elements directly reported by patients about experiences with care, including symptoms, functional status, or quality of life. There is growing interest in the medical community for the evaluation and implementation of PROs of adverse events (PRO-AEs). Recent interest in PROs in health care has evolved in the context of patient centeredness. Our primary objective was to identify trials that had implemented PRO-AEs in the breast cancer treatment setting, thereby demonstrating its feasibility. We aimed to identify published studies that used patient reports to assess AEs during and after breast cancer treatment, to identify clinician underreported and modifiable AEs that are important to patients, and to analyze the feasibility and usefulness of PRO instrument implementation in everyday oncological practice with special attention given to electronic-based PRO instruments.

METHODS

We conducted a systematic search of PubMed for studies that used PRO instruments to assess AEs of breast cancer treatment in the metastatic and adjuvant settings. Two authors independently reviewed the search results and decided which studies fully met the predefined inclusion criteria.

RESULTS

The search yielded 606 publications. The two reviewers found that 9 studies met the inclusion criteria. Three AEs were identified as important to patients but inadequately reported by health care providers, namely hot flushes, vaginal dryness, and weight gain.

CONCLUSIONS

PROs and PRO-AEs are the consequence of contemporary concepts of patient-centered medicine and the growing feasibility, utility, and implications of collecting data using modern technology. Furthermore, the willingness of patients to utilize innovative applications for their own health has been increasing in parallel to the enhanced impact of the World Wide Web. Especially, the coverage of the metastatic situation promises numerous findings on the structure and quality of health care, enabling implementation of individually tailored interventions. Remote electronic self-reporting (i.e., home reporting) is feasible and is associated with high compliance levels.

Abstract 3794: Novel therapeutic targets in head and neck cancer

HNSCC is 6th most common malignancy in the world. Despite advances in diagnosis and treatment, the survival rates remain low due to frequent recurrences the biology of which remains unclear. Using functional genomic technologies we identified new therapeutic targets for metastatic disease in HNSCC. Whole genome shRNA screens were conducted in matched sets of cell lines derived from primary tumors and respective metastatic sites, identifying genes essential for cell survival only following metastasis. To test if knockdown of selected targets inhibits metastasis in a therapeutic setting, we established orthotropic model of HNSCC that metastasize to lymph nodes in the mouse. Components of Notch pathway were identified as essential for survival of cells derived from metastatic sites. Whole exome sequencing identified a novel mutation in one of the EGF domains of Notch3 that was acquired only in the metastatic line. Mutations in EGF domains have been reported to influence interaction with specific ligands, dictating which ligand can activate Notch signaling. Our data indicate that metastatic, but not primary tumor cells, undergo apoptosis upon knockdown of Notch3 and that a distinct set of target genes is induced upon interaction between Notch3 and Jag2 ligand. Furthermore, our results indicate that suppression of Notch3 improves survival in mice bearing orthotropic tumors derived from the metastatic HNSCC lines. Our data demonstrate that metastatic cells from head and neck tumors acquire dependency on Notch3 signaling. Novel treatments targeting components of this pathway may prove effective in targeting metastatic cells alone or in combination with conventional therapies.

Citation Format: Maria Kondratyev, Aleksandra Pesic, Stephano Marastoni, Troy Ketela, Jason Moffat, Carl Virtanen, Azin Sayad, Mikhail Bashkurov, Alessandro Dati, Laurie Ailles, Reidar Grenman, Marianne Koritzinsky, Brad Wouters. Novel therapeutic targets in head and neck cancer. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3794.

Vascular calcium channels and high blood pressure: pathophysiology and therapeutic implications

Long-lasting Ca(2+) (Ca(L)) channels of the Ca(v)1.2 gene family are heteromultimeric structures that are minimally composed of a pore-forming alpha(1C) subunit and regulatory beta and alpha(2)delta subunits in vascular smooth muscle cells. The Ca(L) channels are the primary pathways for voltage-gated Ca(2+) influx that trigger excitation-contraction coupling in small resistance vessels. Notably, vascular smooth muscle cells of hypertensive rats show an increased expression of Ca(L) channel alpha(1C) subunits, which is associated with elevated Ca(2+) influx and the development of abnormal arterial tone. Indeed, blood pressure per se appears to promote Ca(L) channel expression in small arteries, and even short-term rises in pressure may alter channel expression. Membrane depolarization has been shown to be one stimulus associated with elevated blood pressure that promotes Ca(L) channel expression at the plasma membrane. Future studies to define the molecular processes that regulate Ca(L) channel expression in vascular smooth muscle cells will provide a rational basis for designing antihypertensive therapies to normalize Ca(L) channel expression and the development of anomalous vascular tone in hypertensive pathologies.

High Blood Pressure Upregulates Arterial L-Type Ca 2+ Channels

Long-lasting Ca 2+ (Ca L ) channels of the Ca v 1.2 gene family contribute to the pathogenesis of abnormal arterial tone in hypertension. The physiological stimulus that enhances Ca L channel current in the vascular smooth muscle cells (VSMCs) remains unknown. The present study investigated if high blood pressure triggers an upregulation of vascular Ca L channel protein. Rat aortae were banded between the origins of the left renal (LR) and right renal (RR) arteries to selectively elevate blood pressure in the proximal RR arteries. After 2 days, the immunoreactivity on Western blots corresponding to the pore-forming α 1C subunit of the Ca L channel was increased 3.25-fold in RR compared with LR arteries. This finding persisted at 28 days and was associated with abnormal Ca 2+ -dependent tone and higher Ca L currents in the VSMCs exposed to high pressure. Based on microelectrode studies indicating that RR arteries were depolarized compared with LR arteries, further studies examined if membrane depolarization, an inherent response of VSMCs to high blood pressure, increased α 1C expression. Isolated rat renal arteries were cultured for 2 days in low K + (4 mmol/L) or depolarizing high K + (30 mmol/L) media. Arteries preconditioned in high K + showed a 5.47-fold increase in α 1C expression, enhanced Ca L channel current, and elevated Ca 2+ -dependent tone. These findings provide the first direct evidence that high blood pressure upregulates the Ca L channel α 1C subunit in VSMCs in vivo and suggest that membrane depolarization is a potential signal involved in this interaction that may contribute to the development of abnormal vascular tone.