ZNF397 Deficiency Triggers TET2-driven Lineage Plasticity and AR-Targeted Therapy Resistance in Prostate Cancer

Cancer cells exhibit phenotypical plasticity and epigenetic reprogramming, which allows them to evade lineage-dependent targeted treatments by adopting lineage plasticity. The underlying mechanisms by which cancer cells exploit the epigenetic regulatory machinery to acquire lineage plasticity and therapy resistance remain poorly understood. We identified Zinc Finger Protein 397 (ZNF397) as a bona fide coactivator of the androgen receptor (AR), essential for the transcriptional program governing AR-driven luminal lineage. ZNF397 deficiency facilitates the transition of cancer cell from an AR-driven luminal lineage to a Ten-Eleven Translocation 2 (TET2)-driven lineage plastic state, ultimately promoting resistance to therapies inhibiting AR signaling. Intriguingly, our findings indicate that a TET2 inhibitor can eliminate the resistance to AR targeted therapies in ZNF397-deficient tumors. These insights uncover a novel mechanism through which prostate cancer acquires lineage plasticity via epigenetic rewiring and offer promising implications for clinical interventions designed to overcome therapy resistance dictated by lineage plasticity.

ZNF397 Loss Triggers TET2-driven Epigenetic Rewiring, Lineage Plasticity, and AR-targeted Therapy Resistance in AR-dependent Cancers

Cancer cells exhibit phenotypical plasticity and epigenetic reprogramming, which allows them to evade lineage-dependent targeted treatments by adopting lineage plasticity. The underlying mechanisms by which cancer cells exploit the epigenetic regulatory machinery to acquire lineage plasticity and therapy resistance remain poorly understood. We identified Zinc Finger Protein 397 (ZNF397) as a bona fide co-activator of the androgen receptor (AR), essential for the transcriptional program governing AR-driven luminal lineage. ZNF397 deficiency facilitates the transition of cancer cell from an AR-driven luminal lineage to a Ten-Eleven Translocation 2 (TET2)-driven lineage plastic state, ultimately promoting resistance to therapies inhibiting AR signaling. Intriguingly, our findings indicate that TET2 inhibitor can eliminate the AR targeted therapies resistance in ZNF397-deficient tumors. These insights uncover a novel mechanism through which prostate and breast cancers acquire lineage plasticity via epigenetic rewiring and offer promising implications for clinical interventions designed to overcome therapy resistance dictated by lineage plasticity.

Statement of Significance

This study reveals a novel epigenetic mechanism regulating tumor lineage plasticity and therapy response, enhances understanding of drug resistance and unveils a new therapeutic strategy for prostate cancer and other malignancies. Our findings also illuminate TET2's oncogenic role and mechanistically connect TET2-driven epigenetic rewiring to lineage plasticity and therapy resistance.

Loss of SYNCRIP unleashes APOBEC-driven mutagenesis, tumor heterogeneity, and AR-targeted therapy resistance in prostate cancer

Tumor mutational burden and heterogeneity has been suggested to fuel resistance to many targeted therapies. The cytosine deaminase APOBEC proteins have been implicated in the mutational signatures of more than 70% of human cancers. However, the mechanism underlying how cancer cells hijack the APOBEC mediated mutagenesis machinery to promote tumor heterogeneity, and thereby foster therapy resistance remains unclear. We identify SYNCRIP as an endogenous molecular brake which suppresses APOBEC-driven mutagenesis in prostate cancer (PCa). Overactivated APOBEC3B, in SYNCRIP-deficient PCa cells, is a key mutator, representing the molecular source of driver mutations in some frequently mutated genes in PCa, including FOXA1, EP300. Functional screening identifies eight crucial drivers for androgen receptor (AR)-targeted therapy resistance in PCa that are mutated by APOBEC3B: BRD7, CBX8, EP300, FOXA1, HDAC5, HSF4, STAT3, and AR. These results uncover a cell-intrinsic mechanism that unleashes APOBEC-driven mutagenesis, which plays a significant role in conferring AR-targeted therapy resistance in PCa.

Sequential apoptotic and multiplexed proteomic evaluation of single cancer cells

A potential cause of cancer relapse is pretreatment chemoresistant subpopulations. Identifying targetable features of subpopulations that are poorly primed for therapy-induced cell death may improve cancer therapy. Here, we develop and validate real-time BH3 profiling, a live and functional single-cell measurement of pretreatment apoptotic sensitivity that occurs upstream of apoptotic protease activation. On the same single cells, we perform cyclic immunofluorescence, which enables multiplexed immunofluorescence of more than 30 proteins on the same cell. Using cultured cells and rapid ex vivo cultures of colon cancer patient-derived xenograft (PDX) models, we identify Bak as a univariate correlate of apoptotic priming, find that poorly primed subpopulations can correspond to specific stages of the cell cycle, and, in some PDX models, identify increased expression of Bcl-XL, Mcl-1, or Her2 in subpopulations that are poorly primed for apoptosis. Last, we generate and validate mathematical models of single-cell priming that describe how targetable proteins contribute to apoptotic priming.

Ectopic JAK–STAT activation enables the transition to a stem-like and multilineage state conferring AR-targeted therapy resistance

Emerging evidence indicates that various cancers can gain resistance to targeted therapies by acquiring lineage plasticity. Although various genomic and transcriptomic aberrations correlate with lineage plasticity, the molecular mechanisms enabling the acquisition of lineage plasticity have not been fully elucidated. We reveal that Janus kinase (JAK)–signal transducer and activator of transcription (STAT) signaling is a crucial executor in promoting lineage plasticity-driven androgen receptor (AR)-targeted therapy resistance in prostate cancer. Importantly, ectopic JAK–STAT activation is specifically required for the resistance of stem-like subclones expressing multilineage transcriptional programs but not subclones exclusively expressing the neuroendocrine-like lineage program. Both genetic and pharmaceutical inhibition of JAK–STAT signaling resensitizes resistant tumors to AR-targeted therapy. Together, these results suggest that JAK–STAT are compelling therapeutic targets for overcoming lineage plasticity-driven AR-targeted therapy resistance.

3D Visualization Processes for Recreating and Studying Organismal Form

The study of biological form is a vital goal of evolutionary biology and functional morphology. We review an emerging set of methods that allow scientists to create and study accurate 3D models of living organisms and animate those models for biomechanical and fluid dynamic analyses. The methods for creating such models include 3D photogrammetry, laser and CT scanning, and 3D software. New multi-camera devices can be used to create accurate 3D models of living animals in the wild and captivity. New websites and virtual reality/augmented reality devices now enable the visualization and sharing of these data. We provide examples of these approaches for animals ranging from large whales to lizards and show applications for several areas: Natural history collections; body condition/scaling, bioinspired robotics, computational fluids dynamics (CFD), machine learning, and education. We provide two datasets to demonstrate the efficacy of CFD and machine learning approaches and conclude with a prospectus.

Sporobolomyces salmonicolor: A case report of a rare cutaneous fungal infection

We report a case of a 47-year-old male diagnosed with a cutaneous Sporobolomyces salmonicolor infection after suffering with an extensive cutaneous eruption for 4 years. Treatment can be difficult and options include voriconazole and liposomal amphotericin B. This infectious disease is extremely rare and can have extensive impact on multiple organ systems, including the skin.

Change in the Quality of Life in Oropharyngeal, Laryngeal and Hypopharyngeal Cancer Patients treated with Volumetric Modulated Arc-Based Concomitant Boost Radiotherapy

OBJECTIVE

To assess the change in the quality of life (QOL) in Oropharyngeal, Laryngeal and Hypopharyngeal cancer patients treated with concomitant boost radiotherapy by Volumetric Intensity Modulated Arc Therapy (VMAT) technique.

METHODS

Thirty patients with oropharynx, larynx or hypopharynx cancers of stage II to IVA were treated with an Accelerated fractionation schedule using Concomitant boost. The dose given was 1.8Gy/fraction daily, 5 days a week to the large field for 28 fractions and a daily concomitant boost of 1.5Gy/fraction to the boost field over the last 12 treatment days for a total dose of 68.4Gy/40 fractions/5½weeks by VMAT technique with concurrent chemotherapy (in stage III and IV patients) using Cisplatin 100mg/m2 IV three weekly during week 1 and week 4 of irradiation. QOL was assessed using the European Organization of Research and Treatment of Cancer Quality of Life Core Questionnaire, version 3.0 (EORTC QLQC30) and EORTC head and neck module (EORTC QLQ-HN35) before treatment, at the end of treatment, 1 month, 3 months and 6 months post treatment. The QOL scores and their evolution over the five measurements were calculated.

RESULTS

The change in the QOL scores was acceptable in general. There was a significant reduction in quality of life scores at the end of treatment. The QOL improved in the followup period; and by 3 months post irradiation, there was a return of QOL scores to the baseline value.

CONCLUSION

The QOL scores indicate that concomitant boost radiotherapy by VMAT is well tolerated and helps in rapid return to baseline quality of life scores. We believe that this is one of the first papers which have combined concomitant boost radiotherapy with VMAT technique in head and neck cancers. VMAT based concomitant boost radiotherapy helps in rapid return to baseline quality of life.

A single institution 18-years retrospective analysis of malignant melanoma

Melanoma accounts for about 2% of all cancer-related mortality in western populations. Surgical excision of localized disease is curative in many patients with 80% overall 5-year survival rate. There are many indicators of prognosis of which tumor burden is predicted by primary site with nodal status being the next most important variable. Patients with advanced stage have very high risk of developing distant metastases and should receive systemic therapy. Despite treatment, majority of locally advanced patients develop metastatic disease.

MATERIALS AND METHODS

A retrospective analysis of cases of malignant melanoma registered over a period of eighteen years, from October 1990 to September 2007 was done. Patient profile, presentation, disease load, treatment protocols and response on or after treatment were analyzed.

RESULTS

The median age at diagnosis in men was 48 years and 50 years in women. At presentation, more than half of studied cases (56.5%) presented with nodal metastases at diagnosis while about three fourths (74%) had distant metastases (stage IV disease). More than half (56%) of the patients had superficial spreading type. The most common presenting complaints were swelling (70% of patients), ulcer (50% of patients) or pain (50%). Primary sites included extremities, central nervous system, abdomen, trunk, and bones. Liver, brain, abdomen and lungs were common metastatic sites. Surgical excision of primary lesion was done in about half of the cases. Four patients subsequently received palliative radiotherapy and two more received adjuvant radiotherapy. Another six patients received adjuvant chemotherapy and radiotherapy. Among treated patients, 26% showed partial response and another 8% have stable disease while 65% patients progressed on or after initial treatment.

CONCLUSION

Malignant melanoma carries an overall poor prognosis especially in advanced stages. Multimodality therapy with surgery, radiotherapy and chemotherapy may provide local or nodal remission but cannot improve long term survival in advanced cases.

Case report: recurrent olfactory neuroblastoma nasal cavity in young boy refractory to chemotherapy with remission after radiotherapy and sparing of left eye

Olfactory neuroblastomas make up about 3-5% of malignant intra-nasal tumors and originate from the olfactory neuroepithelium lining the roof of the nasal vault. There exist no optimum treatment guidelines from randomized data due to paucity of patients. Treatment options range from minimal surgery to extensive cranio-facial resections and adjuvant radiotherapy. In this case a tumor engulfing optic nerve and globe was safely treated by 3D-CRT with complete remission and relative sparing of the eye as well as late toxicities were avoided. 3D-CRT permits increased dose to tumor sparing critical areas and is a feasible option in centres without IMRT.

Canadian clinical practice guidelines for acute and chronic rhinosinusitis

This document provides health care practitioners with information regarding the management of acute rhinosinusitis (ARS) and chronic rhinosinusitis (CRS) to enable them to better meet the needs of this patient population. These guidelines describe controversies in the management of acute bacterial rhinosinusitis (ABRS) and include recommendations that take into account changes in the bacteriologic landscape. Recent guidelines in ABRS have been released by American and European groups as recently as 2007, but these are either limited in their coverage of the subject of CRS, do not follow an evidence-based strategy, or omit relevant stakeholders in the development of guidelines and do not address the particulars of the Canadian health care environment.Advances in understanding the pathophysiology of CRS, along with the development of appropriate therapeutic strategies, have improved outcomes for patients with CRS. CRS now affects large numbers of patients globally, and primary care practitioners are confronted by this disease on a daily basis. Although initially considered a chronic bacterial infection, CRS is now recognized as having multiple distinct components (eg, infection, inflammation), which have led to changes in therapeutic approaches (eg, increased use of corticosteroids). The role of bacteria in the persistence of chronic infections and the roles of surgical and medical management are evolving. Although evidence is limited, guidance for managing patients with CRS would help practitioners less experienced in this area offer rational care. It is no longer reasonable to manage CRS as a prolonged version of ARS, but, rather, specific therapeutic strategies adapted to pathogenesis must be developed and diffused.Guidelines must take into account all available evidence and incorporate these in an unbiased fashion into management recommendations based on the quality of evidence, therapeutic benefit, and risks incurred. This document is focused on readability rather than completeness yet covers relevant information, offers summaries of areas where considerable evidence exists, and provides recommendations with an assessment of the strength of the evidence base and the degree of endorsement by the multidisciplinary expert group preparing the document.These guidelines have been copublished in both Allergy, Asthma, and Clinical Immunology and the Journal of Otolaryngology-Head and Neck Surgery.

A retrospective study of 18 cases of adenoid cystic cancer at a tertiary care centre in Delhi

CONTEXT

Adenoid cystic carcinoma (ACC) is a rare neoplasm that usually arises from the salivary, lacrimal, or other exocrine glands. It is characteristically locally infiltrative in nature and has a tendency toward local recurrence, high propensity for perineural invasion, and prolonged clinical course.

AIM

To analyze the presentation and natural history of cases of adenoid cystic tumors of salivary glands in our institution; and to compare with the existing literature.

DESIGN AND SETTING

Retrospective study at the Department of Radiotherapy.

MATERIALS AND METHODS

Data on 18 patients of ACC of the salivary glands treated between 2004 and 2008 were reviewed with respect to clinical presentation, stage, and histology.

RESULTS

There were 8 cases of major salivary gland tumors (47%), of which 2 were in the submandibular and 6 were involving the parotid. Ten patients (53%) had minor salivary gland involvement. Two patients had metastasis at the time of presentation. All patients underwent surgery. Radiotherapy was delivered to 16 patients and chemotherapy to 6 patients (concurrent, n = 3 and adjuvant, n = 3) and no adjuvant therapy was given to 2 patients. All patients were alive at a median follow-up of 3 years. No patient developed local or distant failure during the study duration.

CONCLUSION

ACC has locally aggressive behavior. Radiotherapy adjuvant to surgery improves local control in locally advanced disease. Longer follow-up is mandatory in view of incidence of late metastasis.

Canadian clinical practice guidelines for acute and chronic rhinosinusitis

This document provides healthcare practitioners with information regarding the management of acute rhinosinusitis (ARS) and chronic rhinosinusitis (CRS) to enable them to better meet the needs of this patient population. These guidelines describe controversies in the management of acute bacterial rhinosinusitis (ABRS) and include recommendations that take into account changes in the bacteriologic landscape. Recent guidelines in ABRS have been released by American and European groups as recently as 2007, but these are either limited in their coverage of the subject of CRS, do not follow an evidence-based strategy, or omit relevant stakeholders in guidelines development, and do not address the particulars of the Canadian healthcare environment.

Advances in understanding the pathophysiology of CRS, along with the development of appropriate therapeutic strategies, have improved outcomes for patients with CRS. CRS now affects large numbers of patients globally and primary care practitioners are confronted by this disease on a daily basis. Although initially considered a chronic bacterial infection, CRS is now recognized as having multiple distinct components (eg, infection, inflammation), which have led to changes in therapeutic approaches (eg, increased use of corticosteroids). The role of bacteria in the persistence of chronic infections, and the roles of surgical and medical management are evolving. Although evidence is limited, guidance for managing patients with CRS would help practitioners less experienced in this area offer rational care. It is no longer reasonable to manage CRS as a prolonged version of ARS, but rather, specific therapeutic strategies adapted to pathogenesis must be developed and diffused.

Guidelines must take into account all available evidence and incorporate these in an unbiased fashion into management recommendations based on the quality of evidence, therapeutic benefit, and risks incurred. This document is focused on readability rather than completeness, yet covers relevant information, offers summaries of areas where considerable evidence exists, and provides recommendations with an assessment of strength of the evidence base and degree of endorsement by the multidisciplinary expert group preparing the document.

These guidelines have been copublished in both Allergy, Asthma & Clinical Immunology and the Journal of Otolaryngology-Head and Neck Surgery.

HBx protein modulates PI3K/Akt pathway to overcome genotoxic stress-induced destabilization of cyclin D1 and arrest of cell cycle

Growth arrest represents an innate barrier to carcinogenesis. DNA damage and replicational stress are known to induce growth arrest and apoptotic death to avert genomic instability and consequently carcinogenesis. In this study, working on the genotoxic stress induced by hydroxyurea and methylmethanesulfone, we observed a growth arrest at G1/S-phase that was mediated by destabilization of cyclin D1. The growth arrest was independent of the stability of cdc25A and preceded transcriptional up-regulation of p21(waf1). Cyclin D1 destabilization involved its phosphorylation by GSK-3beta at threonine-286, since overexpression of the kinase-dead mutant of GSK-3beta or cyclin D1T(286A) Inutant conferred stability to cyclin D1. Further, overexpression of cyclin D1(T286A) also helped in bypassing G1/S phase growth arrest. We also observed a rapid inactivation of Akt/PKB kinase in the presence of hydroxyurea. Enforced expression of the constitutively active Akt or viral oncoprotein HBx (Hepatitis B virus X protein) was sufficient to overcome growth arrest, independent of ATR signaling and stabilized cyclin D1. Thus, the present work not only establishes cyclin D1 to be a novel mediator of genotoxic stress signaling, but also explains how a deregulated mitogenic signaling or a viral oncoprotein can help bypass growth arrest.

An unusual source of Vibrio alginolyticus-associated otitis: prolonged colonization or freshwater exposure?

Otitis externa and otitis media are commonly encountered in clinical practice. We report an unusual case of otitis externa, which was caused by Vibrio alginolyticus, several months after saltwater exposure. Clinicians need to be aware of this unusual pathogen, especially in refractory cases of ear infections.

Toxin Production and Virulence of Inaba and Ogawa Vibrios

Rabbits receiving the same number of Vibrio cholerae organisms intravenously showed a mortality of 65.5% when injected with the Ogawa subtype, and 15% on injection with the Inaba subtype. With lower doses of Ogawa than of Inaba vibrios, 50% mortality in mice was obtained. Shredding of the intestinal mucosa of the guinea pig was more marked after the application of Ogawa than of Inaba filtrates. Tryptophane enhanced the production of toxic filtrates. Cholera filtrates prepared from 16-hr-old cultures had a higher toxicity than those from growth incubated for 10 days. The toxic component in cholera filtrates can be preserved for months at -10°C.