Hepatocellular Carcinoma in HIV-Infected Patients: Clinical Presentation and Outcomes in a Racially Diverse Urban Population.

PURPOSE: As life expectancy for HIV patients improve, hepatocellular carcinoma (HCC) has become a non-AIDS defining illness with a high impact on morbidity and mortality of HIV-infected individuals. We sought to compare outcomes in HIV- versus non-HIV-infected patients treated for HCC at a multiethnic academic medical health system. METHODS: A retrospective chart review of patients diagnosed with HCC from 1/1/2005 to 12/31/2016 was performed. Differences in characteristics among HIV and non-HIV subjects were assessed. Associations between HIV status, viral load, CD4 count, and overall survival (OS) were also assessed. RESULTS: We identified 915 subjects (842 non-HIV and 73 with HIV). HIV-infected subjects were younger, predominantly male non-Hispanic Blacks, and more likely to have HBV and HCV co-infection, and alcohol use at diagnosis compared to non-HIV counterparts. Stage, MELD score, Child-Pugh, and ECOG performance status were similar. HIV-positive patients received systemic therapy at significantly higher rates and liver transplantation for HCC at significantly lower rates than those without HIV. The actuarial 3- and 5-year overall survival (OS) for all patients was 48.3% and 39.4%. For HIV-infected subjects, 3- and 5-year OS was significantly worse at 36.8% and 28.3% compared to 49.3% and 40.4%, respectively, for non-HIV subjects (log rank p = 0.033). CONCLUSIONS: HIV-infected HCC patients have lower survival rates compared to those without HIV. Despite younger age and similar stage, MELD, and ECOG at diagnosis, HIV portends worse outcomes in patients with HCC.

The uncharacterized SANT and BTB domain-containing protein SANBR inhibits class switch recombination.

Class switch recombination (CSR) is the process by which B cells switch production from IgM/IgD to other immunoglobulin isotypes, enabling them to mount an effective immune response against pathogens. Timely resolution of CSR prevents damage due to an uncontrolled and prolonged immune response. While many positive regulators of CSR have been described, negative regulators of CSR are relatively unknown. Using an shRNA library screen targeting more than 28,000 genes in a mouse B cell line, we have identified a novel, uncharacterized protein of 82kD (KIAA1841, NM_027860), which we have named SANBR (SANT and BTB domain regulator of CSR), as a negative regulator of CSR. The purified, recombinant BTB domain of SANBR exhibited characteristic properties such as homodimerization and interaction with corepressor proteins, including HDAC and SMRT. Overexpression of SANBR inhibited CSR in primary mouse splenic B cells, and inhibition of CSR is dependent on the BTB domain while the SANT domain is largely dispensable. Thus, we have identified a new member of the BTB family that serves as a negative regulator of CSR. Future investigations to identify transcriptional targets of SANBR in B cells will reveal further insights into the specific mechanisms by which SANBR regulates CSR as well as fundamental gene regulatory activities of this protein.

Emerging uses of biomarkers in lung cancer management: molecular mechanisms of resistance.

Management of patients with advanced non-small cell lung cancer (NSCLC) has recently been transformed by molecularly targeted and immunotherapeutic agents. In patients with EGFR/ALK/ROS mutated NSCLC, first line molecular therapy is the standard of care. Moreover, immune checkpoint inhibitors are revolutionary treatment options for advanced NSCLC and are now the standard of care in front-line or later line settings. Both classes of agents have led to improved patient outcomes, however, primary resistance and development of acquired resistance to both targeted and immunotherapeutic agents is commonly observed, limiting the use of these agents in clinical settings. In this review, we will discuss the most recent advances in understanding the mechanisms of primary and acquired resistance, progress in the spectrum of assays detecting causative molecular events and the development of new generations of inhibitors to overcome acquired resistance.

A DNA break- and phosphorylation-dependent positive feedback loop promotes immunoglobulin class-switch recombination.

The ability of activation-induced cytidine deaminase (AID) to efficiently mediate class-switch recombination (CSR) is dependent on its phosphorylation at Ser38; however, the trigger that induces AID phosphorylation and the mechanism by which phosphorylated AID drives CSR have not been elucidated. Here we found that phosphorylation of AID at Ser38 was induced by DNA breaks. Conversely, in the absence of AID phosphorylation, DNA breaks were not efficiently generated at switch (S) regions in the immunoglobulin heavy-chain locus (Igh), consistent with a failure of AID to interact with the endonuclease APE1. Additionally, deficiency in the DNA-damage sensor ATM impaired the phosphorylation of AID at Ser38 and the interaction of AID with APE1. Our results identify a positive feedback loop for the amplification of DNA breaks at S regions through the phosphorylation- and ATM-dependent interaction of AID with APE1.