Sox2 maintains self-renewal of tumor initiating cells in osteosarcomas

Tumors are thought to be sustained by a reservoir of self-renewing cells, termed tumor initiating cells or cancer stem cells. Osteosarcomas are high-grade sarcomas derived from osteoblast progenitor cells and are the most common pediatric bone malignancy. In this report we show that the stem cell transcription factor Sox2 is highly expressed in human and murine osteosarcoma cell lines as well as in tumor samples. Osteosarcoma cells have increased ability to grow in suspension as osteospheres, that are greatly enriched in expression of Sox2 and the stem cell marker, Sca-1. Depletion of Sox2 by shRNAs in independent murine osteosarcoma-derived cells drastically reduces their transformed properties in vitro and their ability to form tumors. Sox2-depleted osteosarcoma cells can no longer form osteospheres, and differentiate into mature osteoblasts. Concomitantly, they exhibit decreased Sca-1 expression and upregulation of the Wnt signaling pathway. Thus, despite other mutations, these tumor cells maintain a proliferative requirement for Sox2. Our data indicate that Sox2 is required for osteosarcoma cell self-renewal, and that Sox2 antagonizes the pro-differentiation Wnt pathway, that can in turn reduce Sox2 expression. These studies define Sox2 as a survival factor and a novel biomarker of self-renewal in osteosarcomas, and support a tumor suppressive role for the Wnt pathway in tumors of mesenchymal origin. Our findings could provide the basis for novel therapeutic strategies based on inhibiting Sox2 or enhancing Wnt signaling for the treatment of osteosarcomas

US Cancer Centers of Excellence Strategies for Increased Inclusion of Racial and Ethnic Minorities in Clinical Trials

PURPOSE:: Participation of racial and ethnic minority groups (REMGs) in cancer trials is disproportionately low despite a high prevalence of certain cancers in REMG populations. We aimed to identify notable practices used by leading US cancer centers that facilitate REMG participation in cancer trials. METHODS:: The National Minority Quality Forum and Sustainable Healthy Communities Diverse Cancer Communities Working Group developed criteria by which to identify eligible US cancer centers-REMGs comprise 10% or more of the catchment area; a 10% to 50% yearly accrual rate of REMGs in cancer trials; and the presence of formal community outreach and diversity enrollment programs. Cancer center leaders were interviewed to ascertain notable practices that facilitate REMG accrual in clinical trials. RESULTS:: Eight cancer centers that met the Communities Working Group criteria were invited to participate in in-depth interviews. Notable strategies for increased REMG accrual to cancer trials were reported across five broad themes: commitment and center leadership, investigator training and mentoring, community engagement, patient engagement, and operational practices. Specific notable practices included increased engagement of health care professionals, the presence of formal processes for obtaining REMG patient/caregiver input on research projects, and engagement of community groups to drive REMG participation. Centers also reported an increase in the allocation of resources to improving health disparities and increased dedication of research staff to REMG engagement. CONCLUSION:: We have identified notable practices that facilitate increased participation of REMGs in cancer trials. Wide implementation of such strategies across cancer centers is essential to ensure that all populations benefit from advances in an era of increasingly personalized treatment of cancer

Defining comprehensive biomarker-related testing and treatment practices for advanced non-small-cell lung cancer: Results of a survey of U.S. oncologists

Background: An ASCO taskforce comprised of representatives of oncology clinicians, the American Cancer Society National Lung Cancer Roundtable (NLCRT), LUNGevity, the GO2 Foundation for Lung Cancer, and the ROS1ders sought to: characterize U.S. oncologists\u27 biomarker ordering and treatment practices for advanced non-small-cell lung cancer (NSCLC); ascertain barriers to biomarker testing; and understand the impact of delays on treatment decisions. Methods: We deployed a survey to 2374 ASCO members, targeting U.S. thoracic and general oncologists. Results: We analyzed 170 eligible responses. For non-squamous NSCLC, 97% of respondents reported ordering tests for EGFR, ALK, ROS1, and BRAF. Testing for MET, RET, and NTRK was reported to be higher among academic versus community providers and higher among thoracic oncologists than generalists. Most respondents considered 1 (46%) or 2 weeks (52%) an acceptable turnaround time, yet 37% usually waited three or more weeks to receive results. Respondents who waited ≥3 weeks were more likely to defer treatment until results were reviewed (63%). Community and generalist respondents who waited ≥3 weeks were more likely to initiate non-targeted treatment while awaiting results. Respondents(42%, vs. 19% with ≥6 years of experience). Conclusions: Respondents reported high biomarker testing rates in patients with NSCLC. Treatment decisions were impacted by test turnaround time and associated with practice setting and physician specialization and experience