Mechanisms of resistance to trastuzumab in HER2-positive gastric cancer.

Gastric cancer is one of the most prevalent cancers worldwide, and human epidermal growth factor receptor 2 (HER2)-positive cases account for approximately 20% of the total cases. Currently, trastuzumab + chemotherapy is the recommended first-line treatment for patients with HER2-positive advanced gastric cancer, and the combination has exhibited definite efficacy in HER2-targeted therapy. However, the emergence of drug resistance during treatment considerably reduces its effectiveness; thus, it is imperative to investigate the potential mechanisms underlying resistance. In the present review article, we comprehensively introduce multiple mechanisms underlying resistance to trastuzumab in HER2-positive gastric cancer cases, aiming to provide insights for rectifying issues associated with resistance to trastuzumab and devising subsequent treatment strategies.

[Application of quality constant method in evaluation of Ligusticum chuanxiong pieces].

The method of classifying the quality grade of traditional Chinese medicine slices with cross section model quality constant was applied to the grade evaluation of Ligusticum chuanxiong pieces,and a reasonable grade standard of L. chuanxiong pieces was established. The purpose is to classify the 15 batches of L. chuanxiong pieces by combining the advantages of traditional grading with modern quality control indicators. By measuring the natural morphological parameters,processing parameters and the intrinsic content of ferulic acid,an important active ingredient,of the 15 batches of L. chuanxiong pieces collected from different manufacturers and different batches of different medicinal materials markets,we can synthesize the results. The mass constants and percentage mass constants are calculated and analyzed based on the above data. The results showed that the quality constants of 15 batches of L. chuanxiong pieces collected ranged from 0.53-3.00; if the percentage mass constants were more than 80%,50%-80% was second-class pieces,and the rest were third-class pieces,the evaluation results were as follows: the quality constants of first-class L. chuanxiong pieces were more than 2.40,the quality constants of second-class L. chuanxiong pieces should be 1.70-2.40,and the quality constants of third-class L. chuanxiong pieces should be less than 1.70. In this paper,the method of dividing the quality constants of the top blade model into different grades is further applied and practiced,which proves that the method is scientific,reasonable and multi-adaptable. At the same time,it enriches the research data of the grade evaluation of L. chuanxiong pieces,provides a useful reference for the promotion of the grade evaluation of L. chuanxiong pieces,and lays an experimental foundation for the next research of the subject group.

Analysis of cyclin E co-expression genes reveals nuclear transcription factor Y subunit alpha is an oncogene in gastric cancer.

OBJECTIVE: To explore genes potentially co-expressed with cyclin E in gastric cancer and discover possible targets for gastric cancer treatment. METHODS: The Cancer Genome Atlas (TCGA) stomach adenocarcinoma sequencing data were used to predict genes co-expressed with cyclin E. Co-expression genes predicted by cBioPortal online analysis with Pearson correlation coefficient ≥0.4 were analyzed by gene ontology (GO) enrichment annotation using the PANTHER online platform (Ver. 7). Interactions between proteins encoded by these genes were analyzed using the STRING online platform (Ver. 10.5) and Cytoscape software (Ver. 3.5.1). Genes displaying a high degree of connection were analyzed by transcription factor enrichment prediction using FunRich software (Ver. 3). The significant transcription factor and cyclin E expression levels and their impact on gastric cancer progression were analyzed by Western blotting and Kaplan-Meier survival curve analysis. RESULTS: After filtering the co-expression gene prediction results, 78 predicted genes that included 73 protein coding genes and 5 non-coding genes with Pearson correlation coefficient ≥0.4 were selected. The expressions of the genes were considered to be correlated with cyclin E expression. Among the 78 genes co-expressed with cyclin E, 19 genes at the central of the regulatory network associated with cyclin E were discovered. Nuclear transcription factor Y subunit alpha (NF-YA) was identified as a significant transcription factor associated with cyclin E co-expressing genes. Analysis of specimen donors' clinical records revealed that high expression of NF-YA tended to be associated with increased cyclin E expression. The expression of both was associated with progression of gastric cancer. Western blotting results showed that compared with normal tissues, NF-YA and cyclin E were highly expressed in tumor tissues (P < 0.001). Survival curve analysis clearly demonstrated relatively poor overall survival of gastric cancer patients with high cyclin E or high NF-YA expression level, compared to patients with low cyclin E or NF-YA expression (P < 0.05). CONCLUSIONS: NF-YA may promote gastric cancer progression by increasing the transcription of cyclin E and other cell cycle regulatory genes. NF-YA might be a potential therapeutically useful prognostic factor for gastric cancer.