Surgical tumour resection deregulates Hallmarks of Cancer in resected tissue and the surrounding microenvironment

Surgery exposes tumor tissue to severe hypoxia and mechanical stress leading to rapid gene expression changes in the tumor and its microenvironment, which remain poorly characterized. We biopsied tumor and adjacent normal tissue from breast (BRC) (n=81) and head/neck squamous cancer (HNSC) patients (n=10) at the beginning (A), during (B) and end of surgery (C). Tumor/normal RNA from 46/81 breast cancer patients was subjected to mRNA-Seq using Illumina short-read technology, and from nine HNSC patients to whole transcriptome microarray with Illumina BeadArray. Pathways and genes involved in 7 of 10 known cancer hallmarks, namely, tumour promoting inflammation (TNF-A, NFK-B, IL-18 pathways), activation of invasion & migration [(various Extracellular Matrix (ECM) related pathways, cell migration)], sustained proliferative signaling (K-Ras Signaling), evasion of growth suppressors (P53 signaling, regulation of cell death), deregulating cellular energetics (response to lipid, secreted factors, adipogenesis), inducing angiogenesis (hypoxia signaling, myogenesis), and avoiding immune destruction (CTLA4 and PDL1) were significantly deregulated during surgical resection (time-points A vs B vs C). These findings were validated using NanoString assays in independent pre/intra/post-operative breast cancer samples from 48 patients. In a comparison of gene expression data from biopsy (analogous to time-point A) with surgical resection samples (analogous to time-point C) from The Cancer Genome Atlas (TCGA) study, the top deregulated genes were the same as identified in our analysis, in five of the seven studied cancer types. This study suggests that surgical extirpation deregulates the hallmarks of cancer in primary tumors and adjacent normal tissue across different cancers. Implications: Surgery deregulates hallmarks of cancer in human tissue.

Interferon-stimulated neutrophils as a predictor of immunotherapy response

Despite the remarkable success of anti-cancer immunotherapy, its effectiveness remains confined to a subset of patients-emphasizing the importance of predictive biomarkers in clinical decision-making and further mechanistic understanding of treatment response. Current biomarkers, however, lack the power required to accurately stratify patients. Here, we identify interferon-stimulated, Ly6Ehi neutrophils as a blood-borne biomarker of anti-PD1 response in mice at baseline. Ly6Ehi neutrophils are induced by tumor-intrinsic activation of the STING (stimulator of interferon genes) signaling pathway and possess the ability to directly sensitize otherwise non-responsive tumors to anti-PD1 therapy, in part through IL12b-dependent activation of cytotoxic T cells. By translating our pre-clinical findings to a cohort of patients with non-small cell lung cancer and melanoma (n = 109), and to public data (n = 1440), we demonstrate the ability of Ly6Ehi neutrophils to predict immunotherapy response in humans with high accuracy (average AUC ≈ 0.9). Overall, our study identifies a functionally active biomarker for use in both mice and humans.

IFN-β mediates the anti-osteoclastic effect of bisphosphonates and dexamethasone

Zoledronic acid (Zol) is a potent bisphosphonate that inhibits the differentiation of monocytes into osteoclasts. It is often used in combination with dexamethasone (Dex), a glucocorticoid that promotes the resolution of inflammation, to treat malignant diseases, such as multiple myeloma. This treatment can result in bone pathologies, namely medication related osteonecrosis of the jaw, with a poor understanding of the molecular mechanism on monocyte differentiation. IFN-β is a pro-resolving cytokine well-known as an osteoclast differentiation inhibitor. Here, we explored whether Zol and/or Dex regulate macrophage osteoclastic differentiation via IFN-β. RAW 264.7 and peritoneal macrophages were treated with Zol and/or Dex for 4–24 h, and IFN-β secretion was examined by ELISA, while the IFN stimulated gene (ISG) 15 expression was evaluated by Western blotting. RANKL-induced osteoclastogenesis of RAW 264.7 cells was determined by TRAP staining following treatment with Zol+Dex or IFN-β and anti-IFN-β antibodies. We found only the combination of Zol and Dex increased IFN-β secretion by RAW 264.7 macrophages at 4 h and, correspondingly, ISG15 expression in these cells at 24 h. Moreover, Zol+Dex blocked osteoclast differentiation to a similar extent as recombinant IFN-β. Neutralizing anti-IFN-β antibodies reversed the effect of Zol+Dex on ISG15 expression and partially recovered osteoclastic differentiation induced by each drug alone or in combination. Finally, we found Zol+Dex also induced IFN-β expression in peritoneal resolution phase macrophages, suggesting these drugs might be used to enhance the resolution of acute inflammation. Altogether, our findings suggest Zol+Dex block the differentiation of osteoclasts through the expression of IFN-β. Revealing the molecular pathway behind this regulation may lead to the development of IFN-β-based therapy to inhibit osteoclastogenesis in multiple myeloma patients.

Elevated USP9X drives early-to-late-stage oral tumorigenesis via stabilisation of anti-apoptotic MCL-1 protein and impacts outcome in oral cancers

BACKGROUND

Overexpression of anti-apoptotic MCL-1 protein in oral squamous cell carcinoma (OSCC) is linked to disease progression, therapy resistance and poor outcome. Despite its characteristic short half-life owing to ubiquitin-proteasome-dependent degradation, oral tumours frequently show elevated MCL-1 protein expression. Hence, we investigated the role of deubiquitinase USP9X in stabilising MCL-1 protein and its contribution to oral tumorigenesis.

METHODS

Expression of MCL-1 and USP9X was assessed by immunoblotting and immunohistochemistry in oral cancer cell lines and tissues. The association between MCL-1 and USP9X was confirmed by coimmunoprecipitation and immunofluorescence. Cell death assessment was performed by MTT, flow cytometry and clonogenic assays.

RESULTS

Both USP9X and MCL-1 are significantly elevated in oral premalignant lesions and oral tumours versus normal mucosa. USP9X interacts with and deubiquitinates MCL-1, thereby stabilising it. Pharmacological inhibition of USP9X potently induced cell death in OSCC cells in vitro and in vivo. The elevated expression of USP9X and MCL-1 correlated with poor prognosis in OSCC patients.

CONCLUSION

We demonstrate the oncogenic role of USP9X in driving early-to-late stages of oral tumorigenesis via stabilisation of MCL-1, suggesting its potential as a prognostic biomarker and therapeutic target in oral cancers.

Abstract 4524: The effect of acute intraoperative hypoxia in breast cancer

Background: Hypoxia is defined as oxygen levels in tumor microenvironment of less than that in blood (90-100 mm Hg) and influences many aspects of tumour biology. During surgery tumour vasculature is cut off gradually leading to induction of acute hypoxia.The present study aims to experimentally test the genotypic and phenotypic effects of surgically induced acute hypoxia in breast cancer tumor samples and cell lines.

Methodology: Core biopsy samples were collected from breast tumors (N=8 patients) at three time points during their curative surgery: prior (pre), mid-way (intra) and at the end (post). The samples were subjected to RNA-Seq and a list of differentially expressed genes (DEG) was prepared. A set of 26 DEG (‘pre’ Vs ‘intra’ Vs ‘post’) obtained from RNA-Seq analysis and additional 17 genes involved in inflammation, EMT and hypoxia pathways were chosen for validation in tumor samples. These genes were validated using a customized qPCR Array (Qiagen). A gene was considered validated if it was significantly deregulated in at least 4 out of 8 patients. In another experiment, MCF-7 cells were exposed to varying levels of oxygen concentrations (0.1-20%) for varying time periods ranging from 30 minutes to 72 hours, to study time and dose dependent effects of hypoxia on following functional characteristics: proliferation, invasion and cell cycle changes.

Results: Concordant, statistically significant up-regulation of FOS, DUSP1, JUNB, FOSB, ZFP36, RGS1, S100A4, CXCL8 and CCL2 were observed in RNA-Seq and qPCR experiments while MMP13, HIF1A and VEGFA were up-regulated only in qPCR. However, 7 protein markers of inflammation, EMT and hypoxia did not show any significant change between pre, intra and post-operative samples. In MCF-7 cells, a dose and time dependent decrease in cell viability was observed with increasing severity of hypoxia as well as decrease in invasiveness, but there was no significant impact on cell cycle phases. When hypoxic cells were re-incubated under normoxic conditions an increase in cell proliferation and accumulation of cells in S phase (with a reduction in G2-M fraction) were observed, compared to cells grown under only normoxic conditions.

Conclusion: Acute intra-operative hypoxia up-regulates expression of genes related to cell survival, chemoresistance, invasiveness, inflammation and angiogenesis in breast tumors. Breast cancer cells exposed to acute severe hypoxia followed by normoxia show increased proliferation. These effects may have implications for tumor cells that disseminate during surgery.

Citation Format: Dimple R. Bhatia, Shalaka Joshi, Rohan Chaubal, Poonam Gera, Prajakta Kalkar, Farheen Naeem, Nisanth Mathew Raju, Nilesh Gardi, Nita Nair, Vaibhav Vanmali, Rohini W. Hawaldar, Amit Dutt, Rajendra A. Badwe, Sudeep Gupta. The effect of acute intraoperative hypoxia in breast 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 4524. doi:10.1158/1538-7445.AM2017-4524

Human papillomavirus/p16 positive head and neck cancer in India: Prevalence, clinical impact, and influence of tobacco use

BACKGROUND

Limited data are available on the prevalence and prognostic significance of human papillomavirus (HPV) in squamous cell carcinoma of head and neck (SCCHN) in the Indian population.

AIM

The present study aimed to determine the prevalence of HPV and p16 in an Indian cohort of SCCHN and assess their correlation and influence of tobacco use on patient outcomes.

MATERIALS AND METHODS

The p16 and HPV status of 170 patients of SCCHN treated with curative chemoradiotherapy was determined using immunohistochemistry and polymerase chain reaction, respectively, and further correlated with their demographic characteristics. In addition, genotyping of HPV-positive samples was performed. Survival outcomes were analyzed and compared for both p16 positive (p16 +ve) and p16 negative (p16 -ve) population. The influence of tobacco use on outcomes was assessed.

RESULTS

p16 expression was observed in 20% (34/170) cases whereas HPV positivity was detected in 39.4% (67/170) of SCCHN patients with HPV16 being the most common (91%) subtype. About 73.5% patients were p16 +ve among the tobacco users in this cohort (83.5%). Interestingly, p16 positivity was significantly associated with nonusers of tobacco (P = 0.02) and younger females (P = 0.06). The p16 +ve and p16 -ve groups did not exhibit a significant difference in the 5-year cause-specific survival (CSS) (79% vs. 72.2%), disease-free survival (DFS) (78.3% vs. 68.3%, P = 0.5), and locoregional control (LRC) (82.2% vs. 71.5%, P = 0.4). However, the outcome analyses in tobacco nonusers revealed a definite large improvement in CSS (P = 0.08) and a trend toward improvement in DFS (P = 0.15) and LRC (P = 0.11) in the p16 +ve versus the p16 -ve groups.

CONCLUSION

The low prevalence of p16 positivity (20%) and dual HPV and p16 positivity (38.8%) in the studied Indian cohort indicates the low utility of p16 as a surrogate for HPV in the background of high tobacco burden. The outcomes are largely improved in a small subset of SCCHN cases comprising p16 +ve tobacco nonusers.