Faculty Bibliography

Inappropriate ordering practices, either under or over ordering of diagnostic tests, are recognized problems with possible negative downstream consequences. As the menu of clinical tests, especially molecular tests grows, it is becoming increasingly important to provide guidance to providers on the appropriate utilization. Diagnostic stewardship programs have been established at many institutions to help direct the appropriate utilization of laboratory testing to ultimately guide patient management and treatment decisions. Many molecular tests have now received Clinical Laboratory Improvement Amendments (CLIA)-waived status for use in a point-of-care (POC) setting; however, parallel diagnostic stewardship programs have not been established to help guide providers on how best to use these tests. In this article, we will discuss the available molecular POC tests and opportunities and challenges for establishing diagnostic stewardship programs for molecular testing performed in the POC setting.

A common metabolic alteration in the tumor microenvironment (TME) is lipid accumulation, a feature associated with immune dysfunction. Here, we examined how CD8⁺ tumor infiltrating lymphocytes (TILs) respond to lipids within the TME. We found elevated concentrations of several classes of lipids in the TME and accumulation of these in CD8⁺ TILs. Lipid accumulation was associated with increased expression of CD36, a scavenger receptor for oxidized lipids, on CD8⁺ TILs, which also correlated with progressive T cell dysfunction. Cd36^-/- T cells retained effector functions in the TME, as compared to WT counterparts. Mechanistically, CD36 promoted uptake of oxidized low-density lipoproteins (OxLDL) into T cells, and this induced lipid peroxidation and downstream activation of p38 kinase. Inhibition of p38 restored effector T cell functions in vitro, and resolution of lipid peroxidation by overexpression of glutathione peroxidase 4 restored functionalities in CD8⁺ TILs in vivo. Thus, an oxidized lipid-CD36 axis promotes intratumoral CD8⁺ T cell dysfunction and serves as a therapeutic avenue for immunotherapies.

We previously reported that E2F1 expression is up-regulated and positively correlated with the malignant phenotypes of colorectal cancer (CRC). However, the underlying mechanisms leading to the aberrant up-regulation of E2F1 in CRC have not been clarified. In this study, we observed that miR-526b-3p directly targets the 3'UTR of E2f1 mRNA, leading to reduced E2F1 expression. Overexpression of miR-526b-3p inhibited the proliferation of CRC cells by decreasing the level of E2F1. We also found that the Ying Yang 1 (YY1)-dependent transcriptional suppression of miR-526b-3p is responsible for the up-regulation of E2F1 in CRC, in which YY1 binds to the promoter of miR-526b gene and recruits histone deacetylase (HDAC). Knockdown of YY1 led to cell cycle arrest and diminished colony formation in CRC cells partly through relieving the miR-526b-3p suppression. Clinical analysis showed that YY1 and E2F1 were negatively correlated with miR-526b-3p in CRC tissues. Moreover, a high level of YY1 and E2F1, or a low level of miR-526b-3p, predicted poor survival of CRC patients. In conclusion, our findings highlight the dysregulation of the YY1/miR-526b-3p/E2F1 axis in CRC development, implicating a novel regulatory pathway for E2F1 as a potential therapeutic target in CRC.

Human papillomaviruses (HPVs) replicate in the cutaneous and mucosal epithelia, and the infectious cycle is synchronous with the differentiation program of the host keratinocytes. The virus initially infects dividing cells in the lower layers of the epithelium, where it establishes a persistent infection. The viral genome is maintained as a low-copy-number, extrachromosomal element in these proliferating cells but switches to the late stage of the life cycle in differentiated cells. The cellular chromatin adaptor protein Brd4 is involved in several stages and processes of the viral life cycle. In concert with the viral transcriptional regulator E2, Brd4 can repress transcription from the early viral promoter. Brd4 and E2 form a complex with the viral genome that associates with host chromosomes to partition the viral genome in dividing cells; Brd4 also localizes to active sites of productive HPV DNA replication. However, because of the difficulties in producing HPV viral particles, the role of Brd4 in modulating viral transcription and replication at the initial stage of infection is unclear. In this study, we have used an HPV18 quasivirus-based genome delivery system to assess the role of Brd4 in the initial infectivity of primary human keratinocytes. We show that, upon infection of primary human keratinocytes with HPV18 quasivirus, Brd4 activates viral transcription and replication. Furthermore, this activation is independent of the functional interaction between Brd4 and the HPV18 E2 protein.

BACKGROUND: Sequence variants located at 15q25 have been associated with lung cancer and propensity to smoke. We recently reported an association between rs16969968 and risk of upper aerodigestive tract (UADT) cancers (oral cavity, oropharynx, hypopharynx, larynx, and esophagus) in women (OR = 1.24, P = 0.003) with little effect in men (OR = 1.04, P = 0.35). METHODS: In a coordinated genotyping study within the International Head and Neck Cancer Epidemiology (INHANCE) consortium, we have sought to replicate these findings in an additional 4,604 cases and 6,239 controls from 10 independent UADT cancer case-control studies. RESULTS: rs16969968 was again associated with UADT cancers in women (OR = 1.21, 95% CI = 1.08-1.36, P = 0.001) and a similar lack of observed effect in men [OR = 1.02, 95% CI = 0.95-1.09, P = 0.66; P-heterogeneity (P(het)) = 0.01]. In a pooled analysis of the original and current studies, totaling 8,572 UADT cancer cases and 11,558 controls, the association was observed among females (OR = 1.22, 95% CI = 1.12-1.34, P = 7 x 10(-6)) but not males (OR = 1.02, 95% CI = 0.97-1.08, P = 0.35; P(het) = 6 x 10(-4)). There was little evidence for a sex difference in the association between this variant and cigarettes smoked per day, with male and female rs16969968 variant carriers smoking approximately the same amount more in the 11,991 ever smokers in the pooled analysis of the 14 studies (P(het) = 0.86). CONCLUSIONS: This study has confirmed a sex difference in the association between the 15q25 variant rs16969968 and UADT cancers. IMPACT: Further research is warranted to elucidate the mechanisms underlying these observations

BACKGROUND: The usual criteria for analysis of hepatitis B surface antigen (HBsAg) are detection of HBsAg and result confirmation by antibody neutralization. We observed that with the Immulite 2000 HBsAg assay [Diagnostics Product Corporation (DPC)] a relatively high percentage of weakly reactive (WR) samples did not pass the neutralization step. METHODS: For each of 3 lots of Immulite 2000 HBsAg reagent (DPC), we collected and analyzed HBsAg data from approximately 3000 to 4000 patient blood samples and compared these data with HBsAg data from 3393 samples tested with the Abbott Auszyme assay. For 127 samples with initially WR detection signals (relative signal/cutoff index of 1.00-2.5) on the Immulite 2000 HBsAg assay, we then measured hepatitis B (HB) viral load and/or other HB serologic markers. RESULTS: The Immulite 2000 HBsAg assay produced more initially reactive results than the Abbott Auszyme method. Many of these reactive samples, however, were WR and did not meet the confirmation criteria in the neutralization test. Moreover, DNA PCR testing indicated that 22 of the 38 WR samples (58%) that did meet the confirmation criteria had no detectable HB viral DNA. CONCLUSIONS: Immulite 2000 HBsAg assay results include a unique group of WR samples that are associated with both false-positive and false-negative results, regardless of neutralization status, and require careful interpretation. WR HBsAg samples should be reported as confirmed HBsAg reactive only if the samples not only meet the neutralization criteria but also are positive for other HB serologic markers such as anti-HB core total and anti-HB core IgM

BACKGROUND: This study evaluated the performance of 2 Bayer Hepatitis B Chemiluminescent Assays by comparing their performance to the corresponding DPC Immulite 2000 assays. METHODS: 953 samples were tested by both Immulite 2000 and Centaur HBsAg methods; and 75 samples were tested by both Immulite 2000 and Centaur anti-HBc IgM methods. RESULTS: The overall agreement between Immulite 2000 and ADVIA Centaur anti-HBc IgM assays was 100%. The agreement between Immulite 2000 and Centaur HBsAg assays was 100% for Immulite 2000 positive samples. The overall agreement for HBsAg negative samples was 99.9% after confirmation result was included. However, discrepancy between the 2 assays was observed in 53 samples which were tested initially as 'weakly reactive'(index 1.0-1.95) but were not confirmed subsequently by the neutralization test on Immulite 2000. All 53 samples tested negative by Centaur HBsAg assay at the initial run. Furthermore, one Immulite 2000 HBsAg negative sample was reactive and confirmed by Centaur assay. CONCLUSIONS: While the performance of Bayer Hepatitis B HBsAg and aHBc IgM assays are in good agreement with corresponding DPC assays, the Bayer HBsAg assay is more efficient than the Immulite 2000 assay with its better separation of signal and background noise, and its complete automation features