Clinical evaluation of a laboratory-developed test using clone E1L3N for the detection of PD-L1 expression status in non-small cell lung cancer.

BACKGROUND: Programmed death ligand 1 (PD-L1) has been used as a diagnostic marker to identify patients that will benefit from immune checkpoint inhibitors in non-small cell lung cancer (NSCLC). Immunohistochemistry with E1L3N clone is one of the most widely used and inexpensive laboratory-developed tests for PD-L1, but still need to be compared and validated with standard methods for clinical application. METHODS: We investigated the performance of E1L3N clone for PD-L1 testing in 299 tumor tissues of NSCLC patients and its comparability with FDA-approved 22C3 clone. RESULTS: The results show that the negative coincidence rate, weak positive coincidence rate, and positive coincidence rate were 97.4%, 92.2%, and 97.6% using the E1L3N assay relative to the 22C3 assay, respectively. An overall agreement of 96.3% was achieved between these two assays. We also found that the overall concordances were 97.8% and 93.9% for PD-L1 detection in large and small specimens, respectively, and no significant difference was obtained between these two assays (p = 0.076). In addition, the expression of PD-L1 was not detected in tumor tissues of benign lung disease using both the E1L3N and 22C3 assays. CONCLUSION: E1L3N can be used as a reliable alternative antibody clone to evaluate PD-L1 expression status for NSCLC patients.

Costunolide specifically binds and inhibits thioredoxin reductase 1 to induce apoptosis in colon cancer.

Colon cancer is one of the leading causes of cancer-related deaths. A natural sesquiterpene lactone, costunolide (CTD), showed inhibition of cancer development. However, the underlying mechanisms are not known. Here, we have examined the therapeutic activity and novel mechanisms of the anti-cancer activities of CTD in colon cancer cells. Using SPR analysis and enzyme activity assay on recombinant TrxR1 protein, our results show that CTD directly binds and inhibits the activity of TrxR1, which caused enhanced generation of ROS and led to ROS-dependent endoplasmic reticulum stress and cell apoptosis in colon cancer cells. Overexpression of TrxR1 in HCT116 cells reversed CTD-induced cell apoptosis and ROS increase. CTD treatment of mice implanted with colon cancer cells showed tumor growth inhibition and reduced TrxR1 activity and ROS level. In addition, it was observed that TrxR1 was significantly up-regulated in existing colon cancer gene database and clinically obtained colon cancer tissues. Our studies have uncovered the mechanism underlying the biological activity of CTD in colon cancer and suggest that targeting TrxR1 may prove to be beneficial as a treatment option.

Curcumin inhibits apoptosis by modulating Bax/Bcl-2 expression and alleviates oxidative stress in testes of streptozotocin-induced diabetic rats.

SCOPE: The present study was designed to examine the damage caused by high-fat diet and streptozotocin-induced diabetes on the testis of rats and the effects of curcumin against oxidative stress and apoptosis from high-fat diet and diabetes. METHODS: Diabetes was induced by intraperitoneal injection of streptozotocin (30 mg/kg in 0.1 M sodium citrate buffer, pH 4.5) in obese rats. The rats in the obese and diabetic groups were treated with a daily dose of curcumin by intragastric intubation (100 mg/kg body weight) for 8 weeks. Testis tissue sections were stained with hematoxylin-eosin, and apoptosis was identified in situ by using terminal deoxynucleotidyl transferase dUTP nick end labeling. RESULTS: Curcumin treatment improved the histological appearance of the testis and significantly reduced the apoptosis level in the testicular cells of the obese and the diabetic rats. The expression of proliferating cell nuclear antigen (PCNA) was restored in the testis tissues of diabetic rats at the end of curcumin treatment. Molecular analysis demonstrated that curcumin treatment significantly and simultaneously decreased Bax and increased Bcl-2 expressions, therefore elevating the ratio of Bcl-2/Bax. Furthermore, curcumin treatment significantly decreased malondialdehyde (MDA) and increased superoxide dismutase (SOD) levels in testis tissue samples of the diabetic rats. CONCLUSION: Curcumin treatment preserved the morphology of testes; restored the expression of PCNA, MDA, and SOD; and inhibited testicular cell death in diabetic rats. The capability of curcumin in inhibiting oxidative stress and modulating the Bax/Bcl-2-mediated cell death pathway reveals its potential as a therapeutic agent against diabetes.

[Protective effects of Curcumin analogue L6H4 on kidney from type 2 diabetic rats].

OBJECTIVE: To investigate the protective effect of curcumin analogue L6H4 on the kidney from the type 2 diabetic rats. METHODS: Twenty-four SPF male SD rats were randomly divided into 3 groups(n=8):normal control group(NC),diabetes mellitus group(DM) and DM+L6H4-treatment group(DT). After rats were fed with high-fat diet for 4 weeks, both the DM and DT groups were injected with streptozotocin intraperitoneally to induce type 2 diabetes mellitus models. The rats in DT group were given L6H4 by gavage at the dose of 0.2 mg/kg·d for 8 weeks. After the treatment, the 24 h urinary protein, fasting blood glucose (FBG), triglyceride (TG), serum creatinine(Scr),blood urea nitrogen (BUN) and uric acid (UA) were detected biochemically. The pathological changes of the kidneys were observed under light and transmission electron microscopes. The expressions of TGF-ß1, FN and Col IV were detected by immunohistochemistry. RESULTS: The levels of the 24 h urinary protein, FBG, TG, Scr and BUN were elevated significantly in diabetic group(P<0.01). The glomerular volume of DM group rats became irregularly enlarged, diffused mesangial matrix accumulated, with basal membrane proliferous hypertrophy and fusion phenomenon of foot process, the expressions of TGF-ß1,FN and Col-IV were elevated significantly (P<0.05). After treated with L6H4, the levels of the 24 h urinary protein, FBG, TG, Scr and BUN were decreased in DT group compared to DM group (P<0.01), the morphological changes of kidney were ameliorated. The expression levels of TGF-ß1, FN and Col-IV were downregulated (P<0.05). CONCLUSIONS: L6H4 exerts the protective effect on kidneys of type 2 diabetic rats by reducing expression of TGF-ß1, inhibiting secretion of Col-IV and FN, relieving the deposition of the extracellular matrix.