Cyclin D1 is one of the most important oncoproteins that drives cancer cell proliferation and associates with tamoxifen resistance in breast cancer. Here, we identify a lncRNA, DILA1, which interacts with Cyclin D1 and is overexpressed in tamoxifen-resistant breast cancer cells. Mechanistically, DILA1 inhibits the phosphorylation of Cyclin D1 at Thr286 by directly interacting with Thr286 and blocking its subsequent degradation, leading to overexpressed Cyclin D1 protein in breast cancer. Knocking down DILA1 decreases Cyclin D1 protein expression, inhibits cancer cell growth and restores tamoxifen sensitivity both in vitro and in vivo. High expression of DILA1 is associated with overexpressed Cyclin D1 protein and poor prognosis in breast cancer patients who received tamoxifen treatment. This study shows the previously unappreciated importance of post-translational dysregulation of Cyclin D1 contributing to tamoxifen resistance in breast cancer. Moreover, it reveals the novel mechanism of DILA1 in regulating Cyclin D1 protein stability and suggests DILA1 is a specific therapeutic target to downregulate Cyclin D1 protein and reverse tamoxifen resistance in treating breast cancer.

Physagulide I induced apoptosis and cell cycle arrest via ROS generation and the activation of MAPK in human osteosarcoma cells.

Hypermongones A-J (1-10), rare methylated polycyclic polyprenylated acylphloroglucinol derivatives, together with three known simple acylphloroglucinols (11-13) as their plausible biogenetic precursors, were identified from the flowers of Hypericum monogynum. The structures of 1-10 were elucidated by analysis of their 1D and 2D NMR spectroscopic data; the absolute configuration of their polycyclic skeleton was determined by the electronic circular dichroism exciton chirality method and was subsequently confirmed by an X-ray diffraction study of 1. The evaluation of their inhibitory effects on nitric oxide (NO) production in lipopolysaccharide-induced RAW264.7 cells revealed that compound 7 exhibited significant NO inhibition activity, with an IC50 value of 9.5 μM.

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PURPOSE Many patients with breast cancer still relapse after curative treatment. How to identify the ones with high relapse risk remains a critical problem. Circulating tumor DNA (ctDNA) has recently become a promising marker to monitor tumor burden. Whether ctDNA can be used to predict the response and prognosis in patients with breast cancer receiving neoadjuvant chemotherapy (NAC) is unknown. Our study aimed to evaluate the clinical value of the presence and dynamic change of ctDNA to predict the tumor response and prognosis in patients with breast cancer treated with NAC. MATERIALS AND METHODS Fifty-two patients with early breast cancer who underwent NAC were prospectively enrolled. Serial plasma samples before, during, and after NAC and paired tumor biopsies were harvested and subjected to deep targeted sequencing using a large next-generation sequencing panel that covers 1,021 cancer-related genes. RESULTS Positive baseline ctDNA was detected in 21 of 44 patients before NAC. Most patients with positive ctDNA had one or more mutations confirmed in paired primary tumor. The ctDNA level after 2 cycles of NAC was predictive of local tumor response after all cycles of NAC (area under the curve, 0.81; 95% CI, 0.61 to 1.00). ctDNA tracking during NAC outperformed imaging in predicting the overall response to NAC. More importantly, positive baseline ctDNA is significantly associated with worse disease-free survival ( P = .011) and overall survival ( P = .004) in patients with early breast cancer, especially in estrogen receptor–negative patients. CONCLUSION Our study demonstrated that ctDNA can be used to predict tumor response to NAC and prognosis in early breast cancer, providing information to tailor an individual’s therapeutic regimen.