DNA Ligase IV is responsible for sealing of double-strand breaks (DSBs) during nonhomologous end-joining (NHEJ). Inhibiting Ligase IV could result in amassing of DSBs, thereby serving as a strategy toward treatment of cancer. Here, we identify a molecule, SCR7 that inhibits joining of DSBs in cell-free repair system. SCR7 blocks Ligase IV-mediated joining by interfering with its DNA binding but not that of T4 DNA Ligase or Ligase I. SCR7 inhibits NHEJ in a Ligase IV-dependent manner within cells, and activates the intrinsic apoptotic pathway. More importantly, SCR7 impedes tumor progression in mouse models and when coadministered with DSB-inducing therapeutic modalities enhances their sensitivity significantly. This inhibitor to target NHEJ offers a strategy toward the treatment of cancer and improvement of existing regimens.

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Background Curcumin is known for its multitude of medicinal properties, including anti-cancer and migrastatic activity. Efforts to overcome poor bioavailability, stability, and side effects associated with the higher dose of curcumin has led to the development of newer derivatives of curcumin. Thus, the focus of this study is to screen novel curcumin derivatives, namely ST03 and ST08, which have not been reported before, for their cytotoxicity and migrastatic property on cancer cells. Methods Anti-cancer activity of ST03 and ST08 was carried out using standard cytotoxicity assays viz., LDH, MTT, and Trypan blue on both solid and liquid cancer types. Flow cytometric assays and western blotting was used to investigate the cell death mechanisms. Transwell migration assay was carried out to check for migrastatic properties of the compounds. Results Both the compounds, ST03 and ST08, showed ~ 100 fold higher potency on liquid and solid tumour cell lines compared to its parent compound curcumin. They induced cytotoxicity by activating the intrinsic pathway of apoptosis in the breast (MDA-MB-231) and ovarian cancer cell lines (PA-1) bearing metastatic and stem cell properties, respectively. Moreover, ST08 also showed inhibition on breast cancer cell migration by inhibiting MMP1 (matrix metalloproteinase 1). Conclusion Both ST03 and ST08 exhibit anti-cancer activity at nanomolar concentration. They induce cell death by activating the intrinsic pathway of apoptosis. Also, they inhibit migration of the cancer cells by inhibiting MMP1 in breast cancer cells.

The antiapoptotic protein BCL2 is overexpressed in several cancers and contributes to prolonged cell survival and chemoresistance, lending itself as an excellent target for cancer therapy. Here, we report the design, synthesis, and characterization of Disarib, a novel BCL2 inhibitor. Disarib showed selective cytotoxicity in BCL2 high cancer cell lines, and CLL patient primary cells, as compared to BCL2 low cell lines. BCL2 knock down in cells rendered remarkable resistance to Disarib, while sensitivity was regained upon its ectopic expression, establishing target specificity. In silico, biochemical and biophysical studies demonstrated strong affinity of Disarib to BCL2, but not to other antiapoptotic BCL2 family members viz., BCL-xL, BCL2A1 etc. Interestingly, biophysical studies showed that BH1 domain deletion mutant demonstrated~67-fold reduction in BCL2-Disarib interaction, while it was only~20-fold in the case of BH3 deletion mutant, suggesting predominant involvement of the BH1 domain for Disarib binding. Thus, we report identification of a novel BCL2 inhibitor with a unique mechanism of BCL2 inhibition, as opposed to the well-studied BH3 domain targeting.

The authors report on the 44-week open-label extension of the 8-week, double-blind Combination of Olmesartan Medoxomil and Amlodipine Besylate in Controlling High Blood Pressure (COACH) trial in 1684 patients. Initial therapy was amlodipine (AML) plus olmesartan medoxomil (OM) 5+40 mg ⁄ d, up-titrated to AML+OM 10+40 mg ⁄ d plus hydrochlorothiazide (HCTZ) 12.5 mg then 25 mg if patients did not achieve blood pressure (BP) goal (<140 ⁄ 90 mm Hg or <130 ⁄ 80 mm Hg in patients with diabetes). Baseline mean BP decreased from 164 ⁄ 102 mm Hg to 131 ⁄ 82 mm Hg at end of study, with an overall 66.7% of patients, including those with diabetes, achieving BP goal. The BP goal achievement was 80% for AML+OM 5+40 mg ⁄ d, 70.6% for AML+OM 10+40 mg ⁄ d, 66.6% for AML+OM+HCTZ 10+40+12.5 mg ⁄ d, and 46.3% for AML+OM+HCTZ 10+40+25 mg ⁄ d.Study medication was safe and well tolerated. Combination antihypertensive therapy with AML+OMAEHTCZ, up-titrated as necessary, allowed a majority of patients to achieve BP goal.

Resveratrol is one of the most widely studied bioactive plant polyphenols which possesses anticancer properties. Previously we have reported synthesis, characterization and identification of a novel resveratrol analog, SS28. In the present study, we show that SS28 induced cytotoxicity in several cancer cell lines ex vivo with an IC50 value of 3–5 μM. Mechanistic evaluation of effect of SS28 in non-small cell lung cancer cell line (A549) and T-cell leukemic cell line (CEM) showed that it inhibited Tubulin polymerization during cell division to cause cell cycle arrest at G2/M phase of the cell cycle at 12–18 h time period. Immunofluorescence studies confirmed the mitotic arrest upon treatment with SS28. Besides, we show that SS28 binds to Tubulin with a dissociation constant of 0.414 ± 0.11 μM. Further, SS28 treatment resulted in loss of mitochondrial membrane potential, activation of Caspase 9 and Caspase 3, leading to PARP-1 cleavage and finally cell death via intrinsic pathway of apoptosis. Importantly, treatment with SS28 resulted in regression of tumor in mice. Hence, our study reveals the antiproliferative activity of SS28 by disrupting microtubule dynamics by binding to its cellular target Tubulin and its potential to be developed as an anticancer molecule.

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