Improvement of combined modality therapy with cisplatin and radiation using intratumoral drug administration in murine tumors

The aim of these studies was to increase the therapeutic ratio by achieving higher tumor concentrations of cisplatin during the course of a fractionated irradiation treatment. Specific goals were to test, firstly, whether multiple drug injections could be replaced by a single slow release implant of cisplatin, and secondly, whether the therapeutic potential of the combined treatment could be increased by administering the drug intratumorally. Drug administration routes tested were intraperitoneal (i.p.) of drug in solution, intratumoral (i.t.) of drug in solution, and intratumoral of drug in a slow release formulation. The latter consisted of a hydrogel polymer formulated into rods which were implanted into the center of subcutaneous tumors. For drug alone, both i.t. routes (solution or polymer) produced higher therapeutic gains than i.p. administration, as judged by tumor growth delay for a given weight loss. When combined with radiation, dose response curves were always shifted to lower doses and were steeper than for radiation or drug alone, although isobologram analysis indicated additivity. In a first series, drug enhancement ratios ranged from 1.6 to 2.6, and were highest for the i.t. groups. In a second series, X-ray enhancement ratios ranged from 1.1 to 1.7, with overlap between results from the different routes. Therapeutic ratios, however, were highest for the i.t. groups in both series. Slow release rods produced the highest therapeutic gains in the first series, while i.t. administration of drug in solution was approximately as effective in the second series. It is concluded that i.t. administration of cisplatin in a slow release vehicle is a relatively simple and effective way of providing high tumor drug levels during a fractionated radiation scheme which can lead to significant therapeutic improvements compared with administering the drug systemically.     

Differential c-myc protein expression in Burkitt's lymphomas and EBV-transformed lymphoblastoid lines

The levels of c-myc protein expression in three types of Epstein-Barr virus (EBV) transformed human B-cell derived lines were examined with an ELISA assay. Six independently maintained sublines of the same EBV-transformed pro-B-cell line (FLEB-14), six B-cell lines (LCL) and six Burkitt's lymphoma lines (BL) were compared. The average amount of c-myc protein, calculated from at least three independent tests on each line, differed between the three groups. Expressed in relative units, the ratio of the means was 1:2:5 for the LCL:FLEB:BL lines. The differences were statistically significant at P < 0.01.     

Loss of the adenomatous polyposis coli gene and human papillomavirus infection in oral carcinogenesis

Recent evidence suggests that loss of heterozygosity (LOH) of the adenomatous polyposis coli (APC) gene plays a role in colorectal tumorigenesis and other cancers. However, little is known as to whether the APC gene contributes to the pathogenesis of oral squamous cell carcinoma. To assess involvement of both the APC gene and the human papillomavirus (HPV) in the development of oral pre-malignant and malignant lesions, we analysed DNA from 14 paired oral normal and pre-malignant or malignant paraffin-embedded biopsy specimens, and DNA from cultured normal and HPV 16-immortalised oral epithelial cells for the presence of LOH of APC and for HPV infection, using PCR based techniques. LOH of APC occurred in 80% of cases of oral epithelial dysplasia, 67% of carcinoma in situ, 50% of invasive squamous cell carcinoma cases, and in the HPV 16-immortalised oral epithelial cells. HPV was detected in half of the biopsy specimens, with HPV 16 as the dominant type. More than half of the carcinoma cases were found to contain both LOH of APC and HPV infection. These results suggest that LOH of APC is an early event during oral tumorigenesis. Our findings also suggest a strong correlation between HPV infection, particularly HPV 16, and LOH of the APC gene in oral squamous cell carcinomas.     

Germline mutations in 40 cancer susceptibility genes among Chinese patients with high hereditary risk breast cancer

Multigene panel testing of breast cancer predisposition genes have been extensively conducted in Europe and America, which is relatively rare in Asia however. In this study, we assessed the frequency of germline mutations in 40 cancer predisposition genes, including BRCA1 and BRCA2, among a large cohort of Chinese patients with high hereditary risk of BC. From 2015 to 2016, consecutive BC patients from 26 centers of China with high hereditary risk were recruited (n = 937). Clinical information was collected and next-generation sequencing (NGS) was performed using blood samples of participants to identify germline mutations. In total, we acquired 223 patients with putative germline mutations, including 159 in BRCA1/2, 61 in 15 other BC susceptibility genes and 3 in both BRCA1/2 and non-BRCA1/2 gene. Major mutant non-BRCA1/2 genes were TP53 (n = 18), PALB2 (n = 11), CHEK2 (n = 6), ATM (n = 6) and BARD1 (n = 5). No factors predicted pathologic mutations in non-BRCA1/2 genes when treated as a whole. TP53 mutations were associated with HER-2 positive BC and younger age at diagnosis; and CHEK2 and PALB2 mutations were enriched in patients with luminal BC. Among high hereditary risk Chinese BC patients, 23.8% contained germline mutations, including 6.8% in non-BRCA1/2 genes. TP53 and PALB2 had a relatively high mutation rate (1.9 and 1.2%). Although no factors predicted for detrimental mutations in non-BRCA1/2 genes, some clinical features were associated with mutations of several particular genes.     

RTN4在胃癌发病机制中的作用

目的 了解RTN4蛋白在胃癌发病过程中的作用,为揭示胃癌发病的分子机制提供实验资料。方法 将pIRESneo3-RTN4真核表达载体转染胃粘膜上皮GES1细胞,建立RTN4高表达的GES1-RTN4细胞系;通过细胞生长曲线、平皿克隆与软琼脂集落形成实验、流式细胞仪,观察RTN4高表达对GES1细胞生长与增殖、周期与凋亡的影响;利用Western-blot检测GES1-RTN4细胞中IκBα蛋白的表达。结果 GES1-RTN4细胞的生长速度较GES1和GES1-pIRESneo3细胞加快,统计学意义显著（P＜0.01）;GES1-RTN4细胞较GES1和GES1-pIRESneo3细胞克隆体积大、数目多,统计学意义显著（P＜0.01）;GES1-RTN4细胞中S期细胞比例较GES1和GES1-pIRESneo3细胞增加,细胞增殖指数增加,细胞凋亡率降低,统计学意义显著（P＜0.01）;GES1-RTN4细胞中IκBα蛋白表达较GES1和GES1-pIRESneo3细胞减少,统计学意义显著（P＜0.01）。结论 RTN4通过活化NF-κB信号通路,提高细胞增殖指数,抑制细胞凋亡,促进GES1细胞的增殖。     

THSD7A as a marker for paraneoplastic membranous nephropathy

International Urology and Nephrology -     

Porous bioactive diopside (CaMgSi2O6) ceramic microspheres for drug delivery

Ideal bioceramic microspheres for bone regeneration need to be bioactive and degradable, but at the same time possess a controlled drug-release ability. The main disadvantage of the currently available microspheres is their failure to combine these properties. The aim of this study is to develop bioactive ceramic microspheres with optimal properties for use in bone-tissue regeneration. In this study, we utilize diopside (CaMgSi₂O₆, DP) with proven excellent bioactivity and degradation ability to develop microspheres by controlling their porosity and size, and further modify their surface with polymer to enhance and control their drug-loading/release ability. The phase composition, surface and inner microstructure, and porosity of DP microspheres were tested. Results indicate that carbon powders as porogens with various contents determined the porosity of the porous DP microspheres. The drug-loading and release ability of dexamethazone (DEX) from porous DP microspheres was regulated by their porosity and size. Poly(lactide-co-glycolide) modification forms a film on the surface of DP microspheres and resulted in an enhanced DEX-loading and release ability of the microspheres. Results presented here indicate that the developed DP microspheres have the potential to be used as bioactive filling materials for bone-tissue regeneration.     

Histone deacetylase inhibitors inhibit cervical cancer growth through Parkin acetylation-mediated mitophagy

Parkin, an E3 ubiquitin ligase, plays a role in maintaining mitochondrial homeostasis through targeting damaged mitochondria for mitophagy. Accumulating evidence suggests that the acetylation modification of the key mitophagy machinery influences mitophagy level, but the underlying mechanism is poorly understood. Here, our study demonstrated that inhibition of histone deacetylase (HDAC) by treatment of HDACis activates mitophagy through mediating Parkin acetylation, leading to inhibition of cervical cancer cell proliferation. Bioinformatics analysis shows that Parkin expression is inversely correlated with HDAC2 expression in human cervical cancer, indicating the low acetylation level of Parkin. Using mass spectrometry, Parkin is identified to interact with two upstream molecules, acetylase acetyl-CoA acetyltransferase 1 (ACAT1) and deacetylase HDAC2. Under treatment of suberoylanilide hydroxamic acid (SAHA), Parkin is acetylated at lysine residues 129, 220 and 349, located in different domains of Parkin protein. In in vitro experiments, combined mutation of Parkin largely attenuate the interaction of Parkin with PTEN induced putative kinase 1 (PINK1) and the function of Parkin in mitophagy induction and tumor suppression. In tumor xenografts, the expression of mutant Parkin impairs the tumor suppressive effect of Parkin and decreases the anticancer activity of SAHA. Our results reveal an acetylation-dependent regulatory mechanism governing Parkin in mitophagy and cervical carcinogenesis, which offers a new mitophagy modulation strategy for cancer therapy.