Rapalogs induce non-apoptotic,autophagy-dependent cell death in HPV-negative TP53 mutant head and neck squamous cell carcinoma

TP53 is the most frequently mutated gene in head and neck squamous cell carcinoma (HNSCC). Patients with HPV-negative TP53 mutant HNSCC have the worst prognosis, necessitating additional agents for treatment. Since mutant p53 causes sustained activation of the PI3K/AKT/mTOR signaling pathway, we investigated the effect of rapalogs RAD001 and CCI-779 on HPV-negative mutTP53 HNSCC cell lines and xenografts. Rapalogs significantly reduced cell viability and colony formation. Interestingly, rapalogs-induced autophagy with no effect on apoptosis. Pretreatment with autophagy inhibitors, 3-methyladenine (3-MA) and ULK-101 rescued the cell viability by inhibiting rapalog-induced autophagy, suggesting that both RAD001 and CCI-779 induce non-apoptotic autophagy-dependent cell death (ADCD). Moreover, rapalogs upregulated the levels of ULK1 and pULK1 S555 with concomitant downregulation of the mTORC1 pathway. However, pretreatment of cells with rapalogs prevented the ULK-101-mediated inhibition of ULK1 to sustained autophagy, suggesting that rapalogs induce ADCD through the activation of ULK1. To further translate our in vitro studies, we investigated the effect of RAD001 in HPV-negative mutTP53 (HN31 and FaDu) tumor cell xenograft model in nude mice. Mice treated with RAD001 exhibited a significant tumor volume reduction without induction of apoptosis, and with a concomitant increase in autophagy. Further, treatment with RAD001 was associated with a considerable increase in pULK1 S555 and ULK1 levels through the inhibition of mTORC1. 3-MA reversed the effect of RAD001 on FaDu tumor growth suggesting that RAD001 promotes ACDC in HPV-negative mutTP53 xenograft. This is the first report demonstrating that rapalogs promote non-apoptotic ADCD in HPV-negative mutTP53 HNSCC via the ULK1 pathway. Further studies are required to establish the promising role of rapalogs in preventing the regrowth of HPV-negative mutTP53 HNSCC.     

Oral-lung microbiome interactions in lung diseases

The proximity and continuity of the oral cavity and the lower respiratory tract allows the oropharyngeal microbiome to be a major determinant of the lung microbiome. In addition, host-pathogen interactions related to the oropharyngeal microbiome or its metabolites could propagate systemic inflammation or modulate host defense mechanisms that could affect other organs, including the lung. There is increasing appreciation of the pathophysiologic significance of the lung microbiome, not only in the classical infection-related diseases, pneumonia, bronchiectasis, and cystic fibrosis, but also in chronic noninfectious lung diseases, such as chronic obstructive pulmonary disease, asthma, and pulmonary fibrosis. In this review, we will explore the relationship of the oral microbiome with lung diseases, such as pneumonia, chronic obstructive pulmonary disease, asthma, and cystic fibrosis.     

A stapled POL κ peptide targets REV1 to inhibit mutagenic translesion synthesis

Stapled α-helical RIR (Rev1-interacting region) peptides of DNA POL κ bind more effectively to the RIR-interface of the C-terminal recruitment domain of the translesion synthesis DNA polymerase Rev1 than unstapled peptide. The tightest-binding stapled peptide translocates into cells and enhances the cytotoxicity of DNA damaging agents while reducing mutagenesis. Drugs with these characteristics could potentially serve as adjuvants to improve chemotherapy and reduce acquired resistance by inhibiting Rev1-dependent mutagenic translesion synthesis.     

Relationship between early‐life nutrition and ages at menarche and first pregnancy,and childbirth rates of young adults: Evidence from APCAPS in India

India's Integrated Child Development Services (ICDS) provides daily supplementary nutrition and other public health services to women and children. We estimated associations between exposure to early‐childhood ICDS nutrition and adult reproductive outcomes. During 1987–1990, a balanced protein–calorie supplement called “upma”—made from locally available corn–soya ingredients—was rolled out by subdistricts near Hyderabad and offered to pregnant women and children under age 6 years. In a controlled trial, 15 villages received the supplement and 14 did not. We used data from a 2010–2012 resurvey of adults born during the trial (n = 715 in intervention and n = 645 in control arms). We used propensity score matching methods to estimate the associations between birth in an intervention village and menarcheal age, age at first pregnancy, and fertility of adults. We found that women born in the intervention group during the trial, as compared with the control group, had menarche 0.45 (95% confidence interval [CI: 0.22, 0.68]; p < .001) years later and first pregnancy 0.53 (95% CI [0.04, 1.02]; p < .05) years later. Married women from the intervention group had menarche 0.36 (95% CI [0.09, 0.64]; p < .01) years later, first cohabitation with partner 0.8 (95% CI [0.27, 1.33]; p < .01) years later, and first pregnancy 0.53 (95% CI [0.04, 1.02]; p < .05) years later than married women in the control group. There was no significant difference between intervention and control group women regarding whether they had at least one childbirth or the total number of children born. The findings were similar when we employed inverse propensity score weighted regression models.