Factors influencing COVID-19 mortality among cancer patients: A Brazilian multi-institutional study.

Purpose: This study aimed to describe the demographic and clinical characteristics of cancer patients with COVID-19, exploring factors associated with adverse outcomes.

Patients And Methods: This retrospective cohort study methodically extracted and curated data from electronic medical records (EMRs) of numerous healthcare institutions on cancer patients diagnosed with a confirmed SARS-CoV-2 infection between May 2020 and August 2021, to identify risk factors linked to extended hospitalization and mortality. The retrieved information encompassed the patients' demographic and clinical characteristics, including the incidence of prolonged hospitalization, acute complications, and COVID-19-related mortality.

Kynurenine inhibits melanogenesis in human melanocyte-keratinocyte co-cultures and in a reconstructed 3D skin model.

Kynurenine (KYN), the most abundant metabolite of tryptophan, is classically associated with immune tolerance and tumor immune escape. In the last years, KYN is in the spotlight in other biological processes. Here, we showed that KYN inhibited tyrosinase expression and melanin content in primary human melanocyte and keratinocyte co-cultures.

Melanocytes are more responsive to IFN-γ and produce higher amounts of kynurenine than melanoma cells.

A key link between amino acid catabolism and immune regulation in cancer is the augmented tryptophan (Trp) catabolism through the kynurenine pathway (KP), a metabolic route induced by interferon-γ (IFN-γ) and related to poor prognosis in melanomas. Besides its role in cancer, IFN-γ plays a key role in the control of pigmentation homeostasis. Here we measured KP metabolites in human melanoma lines and skin melanocytes and fibroblasts in response to IFN-γ.