RESUMO
The neocortex, the center for higher brain function, first emerged in mammals and has become massively expanded and folded in humans, constituting almost half the volume of the human brain. Primary microcephaly, a developmental disorder in which the brain is smaller than normal at birth, results mainly from there being fewer neurons in the neocortex because of defects in neural progenitor cells (NPCs). Outer radial glia (oRGs), NPCs that are abundant in gyrencephalic species but rare in lissencephalic species, are thought to play key roles in the expansion and folding of the neocortex. However, how oRGs expand, whether they are necessary for neocortical folding, and whether defects in oRGs cause microcephaly remain important questions in the study of brain development, evolution, and disease. Here, we show that oRG expansion in mice, ferrets, and human cerebral organoids requires cyclin-dependent kinase 6 (CDK6), the mutation of which causes primary microcephaly via an unknown mechanism. In a mouse model in which increased Hedgehog signaling expands oRGs and intermediate progenitor cells and induces neocortical folding, CDK6 loss selectively decreased oRGs and abolished neocortical folding. Remarkably, this function of CDK6 in oRG expansion did not require its kinase activity, was not shared by the highly similar CDK4 and CDK2, and was disrupted by the mutation causing microcephaly. Therefore, our results indicate that CDK6 is conserved to promote oRG expansion, that oRGs are necessary for neocortical folding, and that defects in oRG expansion may cause primary microcephaly.
Assuntos
Quinase 6 Dependente de Ciclina , Células Ependimogliais , Microcefalia , Neocórtex , Animais , Quinase 6 Dependente de Ciclina/genética , Quinase 6 Dependente de Ciclina/metabolismo , Células Ependimogliais/citologia , Células Ependimogliais/enzimologia , Furões , Proteínas Hedgehog/metabolismo , Humanos , Camundongos , Microcefalia/genética , Neocórtex/anormalidades , Neocórtex/enzimologia , Células-Tronco Neurais/citologia , Células-Tronco Neurais/enzimologia , Organoides/embriologiaRESUMO
INTRODUCTION: Biomarkers are needed to identify patients with metastatic renal cell carcinoma (mRCC) most likely to benefit from immune checkpoint inhibitors. We examined associations between radiographically assessed body composition (BC) variables and body mass index (BMI) with clinical outcomes for patients with mRCC receiving first-line ipilimumab + nivolumab (ipi/nivo). PATIENTS AND METHODS: We retrospectively reviewed all patients with mRCC treated with first-line ipi/nivo at one institution before June 1, 2021 with an analyzable baseline computed tomography (CT) scan. BC variables (skeletal muscle index [SMI], subcutaneous adipose tissue index [SATI], and visceral adipose tissue index [VATI]) were measured using baseline CT scans. Relationships between BC variables and clinical outcomes were examined using Cox proportional hazard regression models. RESULTS: Ninety-nine patients were analyzed (74% male, 64% overweight/obese, 75% low SMI). Controlling for age, IMDC risk, and sex (for BMI analyses), high vs. low SMI (HR=2.433, CI: 1.397-4.238, P=.0017), high vs. low SATI (HR=1.641, CI: 1.023-2.632, P=.0398), and obese BMI (≥ 30 kg/m2) vs. normal/overweight BMI (<30 kg/m2) (HR=1.859, CI: 1.156-2.989, P=.0105) were significantly associated with progression-free survival (PFS). Median overall survival (OS) for low SMI patients was higher (42.74 months, CI: 26.84, NR) than median OS for high SMI patients (27.01 months, CI: 15.28, NR) (adjusted HR=1.728, CI: 0.909-3.285, P=.0952). No BC variables were significantly associated with OS or objective response rate. CONCLUSIONS: Low SMI and low SATI were associated with significantly better PFS for patients with mRCC receiving first-line ipi/nivo. Radiographic BC variables may be useful prognostic biomarkers in this setting.
Assuntos
Carcinoma de Células Renais , Neoplasias Renais , Humanos , Masculino , Feminino , Carcinoma de Células Renais/patologia , Nivolumabe/uso terapêutico , Ipilimumab/uso terapêutico , Neoplasias Renais/tratamento farmacológico , Neoplasias Renais/patologia , Sobrepeso/induzido quimicamente , Sobrepeso/tratamento farmacológico , Estudos Retrospectivos , Obesidade , Composição Corporal , BiomarcadoresRESUMO
Background: Black patients have a higher incidence and mortality associated with hepatocellular carcinoma (HCC) compared with that of White patients in many retrospective analyses. This study sought to determine whether veterans treated for HCC at the Memphis Veterans Affairs Medical Center (VAMC) in Tennessee showed similar disparities in terms of stage at diagnosis, type of therapy received, and overall survival (OS). Methods: A retrospective review evaluated 132 White and 95 Black patients treated for HCC between 2009 and 2021. We evaluated the impact on OS of age, sex, comorbidities, tumor stage, α-fetoprotein level, method of diagnosis, first-line treatment, systemic treatment, and surgical options offered. Kaplan-Meier analysis was used to investigate differences in OS and cumulative hazard ratio for death. Cox regression multivariate analysis evaluated discrepancies among investigated variables. Results: The study found no significant difference in OS between Black and White veterans with HCC. Significant differences were found in who received surgical treatment and systemic therapy. More White veterans received any form of treatment compared with Black veterans (P < .001), and White veterans were more likely to undergo surgical resection and transplant (P = .052). There was no significant difference between age or stage at diagnosis, receipt of systemic therapy, alcohol, tobacco or drug use, HIV coinfection, or cirrhosis. Conclusions: Black veterans with HCC at the Memphis VAMC were less likely to receive any form of treatment, surgical resection, or transplant compared with White veterans, but this did not have a statistically significant effect on OS.