Racial disparities in staging, treatment, and mortality in non-small cell lung cancer.

Background: Black race is associated with advanced stage at diagnosis and increased mortality in non-small cell lung cancer (NSCLC). Most studies focus on race alone, without accounting for social determinants of health (SDOH). We explored the hypothesis that racial disparities in stage at diagnosis and outcomes are associated with SDOH and influence treatment decisions by patients and providers. Methods: Patients with NSCLC newly diagnosed at Indiana University Simon Comprehensive Cancer Center (IUSCCC) from January 1, 2000 to May 31, 2015 were studied. Multivariable regression analyses were conducted to examine the impact of SDOH (race, gender, insurance status, and marital status) on diagnosis stage, time to treatment, receipt of and reasons for not receiving guideline concordant treatment, and 5-year overall survival (OS) based on Kaplan-Meier curves. Results: A total of 3,349 subjects were included in the study, 12.2% of Black race. Those diagnosed with advanced-stage NSCLC had a significantly higher odds of being male, uninsured, and Black. Five-year OS was lower in those of Black race, male, single, uninsured, Medicare/Medicaid insurance, and advanced stage. Adjusted for multiple variables, individuals with Medicare, Medicare/Medicaid, uninsured, widowed, and advanced stage at diagnosis, were associated with significantly lower OS time. Black, single, widowed, and uninsured individuals were less likely to receive stage appropriate treatment for advanced disease. Those uninsured [odds ratio (OR): 3.876, P<0.001], Medicaid insurance (OR: 3.039, P=0.0017), and of Black race (OR: 1.779, P=0.0377) were less likely to receive curative-intent surgery for early-stage NSCLC because it was not a recommended treatment. Conclusions: We found racial, gender, and socioeconomic disparities in NSCLC diagnosis stage, receipt of stage-appropriate treatment, and reasons for guideline discordance in receipt of curative intent surgery for early-stage NSCLC. While insurance type and marital status were associated with worse OS, race alone was not. This suggests racial differences in outcomes may not be associated with race alone, but rather worse SDOH disproportionately affecting Black individuals. Efforts to understand advanced diagnosis and reasons for failure to receive stage-appropriate treatment by vulnerable populations is needed to ensure equitable NSCLC care.

An RNAi Screen for Genes Required for Growth of Drosophila Wing Tissue.

Cell division and tissue growth must be coordinated with development. Defects in these processes are the basis for a number of diseases, including developmental malformations and cancer. We have conducted an unbiased RNAi screen for genes that are required for growth in the Drosophila wing, using GAL4-inducible short hairpin RNA (shRNA) fly strains made by the Drosophila RNAi Screening Center. shRNA expression down the center of the larval wing disc using dpp-GAL4, and the central region of the adult wing was then scored for tissue growth and wing hair morphology. Out of 4,753 shRNA crosses that survived to adulthood, 18 had impaired wing growth. FlyBase and the new Alliance of Genome Resources knowledgebases were used to determine the known or predicted functions of these genes and the association of their human orthologs with disease. The function of eight of the genes identified has not been previously defined in Drosophila The genes identified included those with known or predicted functions in cell cycle, chromosome segregation, morphogenesis, metabolism, steroid processing, transcription, and translation. All but one of the genes are similar to those in humans, and many are associated with disease. Knockdown of lin-52, a subunit of the Myb-MuvB transcription factor, or ßNACtes6, a gene involved in protein folding and trafficking, resulted in a switch from cell proliferation to an endoreplication growth program through which wing tissue grew by an increase in cell size (hypertrophy). It is anticipated that further analysis of the genes that we have identified will reveal new mechanisms that regulate tissue growth during development.

A Cyclin A-Myb-MuvB-Aurora B network regulates the choice between mitotic cycles and polyploid endoreplication cycles.

Endoreplication is a cell cycle variant that entails cell growth and periodic genome duplication without cell division, and results in large, polyploid cells. Cells switch from mitotic cycles to endoreplication cycles during development, and also in response to conditional stimuli during wound healing, regeneration, aging, and cancer. In this study, we use integrated approaches in Drosophila to determine how mitotic cycles are remodeled into endoreplication cycles, and how similar this remodeling is between induced and developmental endoreplicating cells (iECs and devECs). Our evidence suggests that Cyclin A / CDK directly activates the Myb-MuvB (MMB) complex to induce transcription of a battery of genes required for mitosis, and that repression of CDK activity dampens this MMB mitotic transcriptome to promote endoreplication in both iECs and devECs. iECs and devECs differed, however, in that devECs had reduced expression of E2F1-dependent genes that function in S phase, whereas repression of the MMB transcriptome in iECs was sufficient to induce endoreplication without a reduction in S phase gene expression. Among the MMB regulated genes, knockdown of AurB protein and other subunits of the chromosomal passenger complex (CPC) induced endoreplication, as did knockdown of CPC-regulated cytokinetic, but not kinetochore, proteins. Together, our results indicate that the status of a CycA-Myb-MuvB-AurB network determines the decision to commit to mitosis or switch to endoreplication in both iECs and devECs, and suggest that regulation of different steps of this network may explain the known diversity of polyploid cycle types in development and disease.