OBJECTIVETo investigate the effects of all-trans-retinoic acid(ATRA) and polyphenon-100 (PP) on genetic instability of human tumor cells via their role in alteration of microsatellite sequence(MS) and the expression of mismatch repair gene hMLH(1) and hMSH(2) in RER(+) (replication error) cells.

METHODSRER(+) colon cancer cell line was used as a host for lipofection with pCMV-CAR in which a foreign (CA)(14) repeat was inserted in the coding sequence of LacZ reporter gene, resulting in misreading LacZ frame. Any mutation which made the base number of (CA)(14) tract to be 3-fold resumed normal reading frame of LacZ, and thus led to expression of beta-galactosidase. Variable expression of LacZ in the transfectant cells resulting from RATA or PP treatment was measured by OD reading at lambda 620 after X-gal staining. Expression of mismatch repair genes of hMLH(1) and hMSH(2) was examined at mRNA level by reverse transcription-polymerase chain reaction (RT-PCR).

RESULTSATRA at 1 mu mol/L, 0.1 u mol/L and PP at 3 mu g/ml had no significant inhibitory effect on cell proliferation. After being treated with ATRA or PP for 1 week, the blue cells of RKO transfectant clones were significantly reduced, and this meant the mutation of exogenous (CA)(14) in RKO cells were inhibited. But no expression of hMLH(1) and hMSH(2) was observed.

CONCLUSIONThe above data showed both ATRA and PP had inhibitory effects on MS instability of cancer and thus demonstrated directly their beneficial role in stabilization of genomic DNA. However, the present authors have not observed any expression of hMLH(1) and hMSH(2) in RKO cells treated with ATRA or PP.

Adaptor Proteins, Signal Transducing ; Carrier Proteins ; Catechin ; pharmacology ; Cell Division ; drug effects ; Colonic Neoplasms ; genetics ; pathology ; DNA-Binding Proteins ; Gene Expression ; drug effects ; Humans ; Lac Operon ; genetics ; Microsatellite Repeats ; genetics ; MutL Protein Homolog 1 ; MutS Homolog 2 Protein ; Mutation ; Neoplasm Proteins ; genetics ; Nuclear Proteins ; Plasmids ; genetics ; Proto-Oncogene Proteins ; genetics ; RNA, Messenger ; drug effects ; genetics ; metabolism ; Transfection ; Tretinoin ; pharmacology ; Tumor Cells, Cultured ; drug effects

To investigate the effectiveness and safety of ultrasound-guided microwave ablation (MWA) in treatment of primary hyperparathyroidism (PHPT). A total of 12 PHPT patients with parathyroid adenoma were treated with MWA in Nanjing University of Chinese Medicine Affiliated Hospital of Integrated Traditional Chinese and Western Medicine from May 2019 to February 2021. The patients were followed up once every 3 months for 3-12 months. Levels of serum parathyroid hormone (PTH), calcium and phosphorus were detected before and 20 min, 4h and 1day after ablation, and during follow-up period. The volume and volume reduction rate of parathyroid lesion were compared before the treatment and at the end of follow-up. The technical and clinical success of MWA were assessed as well. At the end of follow-up, median serum PTH [66.60 (42.21,80.03) ng/L vs.169.90 (89.01,396.50) ng/L] and calcium [2.39 (2.32,2.49) mmol/L vs. 2.75 (2.57,2.96) mmol/L] levels in 12 patients decreased significantly (all P<0.05). A complete response in terms of PTH and calcium levels was achieved in 6 of the 12 patients, while 4 of the patients had slightly elevated PTH levels just above the upper limit of normal reference range, and 2 of the patients remained abnormal PTH and calcium levels. The clinical cure rate was 50%. The volumes of all lesion after ablation were significantly decreased ( P<0.05), with the technical success rate reaching 92.3%. No serious complications were observed. Ultrasound-guided MWA, thus, is safe and effective in the treatment of PHPT.