The highly enantioselective synthesis of 4-aryl-3,4-dihydrocoumarins was realized through direct annulation of phenols with enals catalyzed by dihydroisoquinoline-type NHC (DHIQ-NHC), an N-heterocyclic carbene derived from l-phenylalanine. The catalytic reaction proceeds with a wide scope of electron-rich phenols and enals providing structurally diverse 4-aryl-3,4-dihydrocoumarins in good to excellent yields and enantioselectivity. This method was useful in the synthesis of natural products and biologically relevant compounds from readily available starting materials.
Lung cancer is the most common cancer malignancy worldwide. With the continuous spread of the coronavirus disease 2019 (COVID-19) globally, it is of great significance to explore the impact of this disease on the clinical characteristics of lung cancer. Thus, we aimed to investigate whether the COVID-19 pandemic had any influence on the clinical characteristics and diagnosis of patients with lung cancer. We collected clinical and demographic data of patients who were newly diagnosed with lung cancer at our hospital between February 2019 and July 2020. Overall, 387 patients with lung cancer were divided into two groups for analysis: epidemic group (from February to July 2020) and pre-epidemic group (from February to July 2019). The source of diagnosis and clinical characteristics of the two groups were analysed. T-test and Mann-Whitney U were used for continuous variables, and Chi-squared or Fisher’s exact test for categorical variable. We found that during the epidemic period, 110 cases of lung cancer were incidentally diagnosed during COVID-19 screening, accounting for 47.6% of all newly diagnosed lung cancer cases at our hospital. The proportions of patients who were diagnosed based on symptoms and physical examination in the epidemic group were 34.2 and 18.2%, respectively, while that in the pre-epidemic group were 41.7 and 58.3%, respectively. There was significant difference in the source of diagnosis between the two groups. In a subgroup analysis of the epidemic group, the average tumour volume of the patients diagnosed with COVID-19 screening was significantly smaller than that of the patients diagnosed with symptoms and physical examination. In conclusion, the continuation of the COVID-19 pandemic may impact the screening and clinical characteristics of lung cancer and require large-scale and longer-term observation.
Metformin is a promising drug for cancer prevention and treatment, especially in the diabetic population. We aimed to test whether 14-3-3zeta affects the anticancer effect of metformin on colorectal carcinoma (CRC). In this study, we confirmed that higher 14-3-3zeta expression was found in CRC tissues than in pericarcinoma tissues, and in CRC tissue of patients with diabetes than in those without diabetes. A knockdown of 14-3-3zeta inhibited CRC proliferation and promoted apoptosis in vitro and in vivo. Then, we created stable cell lines with under-expressed 14-3-3zeta from SW480 and HCT15 cells after infection by a lentiviral vector carrying short hairpin RNA targeting 14-3-3zeta (named LV-sh14-3-3zeta). Of note, metformin induced apoptosis and retarded tumor growth in the CRCs with overexpressed 14-3-3zeta, whereas this action was attenuated when 14-3-3zeta was knocked down. Moreover, either metformin or downregulation of 14-3-3zeta noticeably activated AMP-dependent protein kinase (AMPK) signaling, whereas the effect of metformin was attenuated when the 14-3-3zeta expression was decreased. Taken together, our results suggest that 14-3-3zeta may be associated with carcinogenesis and poor prognosis of CRCs associated with diabetes, and metformin may reverse the AMPK inhibition caused by 14-3-3zeta in CRCs in the background of diabetes. Our study should lead to a better understanding of the anticancer activity of metformin and points to possible application of metformin to the treatment of cancers overexpressing 14-3-3zeta.
ObjectiveThis study aims to investigate biological behavior changes in a murine lung cancer cell characterized by acquired resistance to sunitinib, a potent inhibitor of multiple-targeted receptor tyrosine kinase.MethodsA lung cancer cell line resistant to sunitinib (LL/2-R) was developed from its parental cell line (LL/2-P). Differences in biological characteristics and associated molecular profiles between these two cells were compared in vitro and in vivo.ResultsLL/2-R cells showed an approximately 5-fold higher IC50 of sunitinib than LL/2-P cells and exhibited a reduced growth inhibition following sunitinib treatment compared with LL/2-P. In LL/2-R cells and tumors, increased migration, invasion and metastasis were observed, along with upregulation of MMP-2 and MMP-9. We also analyzed the molecular profiles involved in EMT, and found that E-cadherin was downregulated in LL/2-R tumors, and vimentin was upregulated in LL/2-R cells and tumors, along with β-catenin translocating to the nuclei in LL/2-R cells. Furthermore, transcriptional factors mediated EMT, snail and twist, and the secretion of TGFβ1 also increased in LL/2-R cells and tumors.ConclusionsWe established a sunitinib-resistant lung cancer cell line and confirmed its drug-resistance to sunitinib in vivo. Our results implied that increased invasion and EMT may associate with the acquisition of resistant phenotype to sunitinib in cancer cells.
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