BACKGROUNDThe expressive level of glucose-regulated protein 78 (GRP78) is elevated and correlated with resistance of chemotherapy drugs in breast cancer cell. However, little is known about the relationship between its expression and drug resistance in non-small cell lung cancer (NSCLC). The aim of this study was to explore the relationship between drug resistance and the expression of GRP78 in NSCLC.

METHODSDrug sensitivity test was used to detect the resistance to 8 chemotherapy drugs in 52 NSCLC fresh surgical samples by methylthiazoletrazolium (MTT), and expression of GRP78 was detected by immunohistochemistry method. Spearman correlation assay was used to investigate the correlation between the GRP78 expression and drug resistance.

RESULTSThe resistance rates to paclitaxel (PTX), adriamycin (ADM), carboplatin (CBP), topotecan (TPT), navelbine (NVB), vincristine (VCR), cisplatin (DDP) and etoposide (VP-16) of the 52 samples were 42.31%, 57.69%, 63.46%, 65.38%, 67.31%, 73.08%, 78.85%, 90.38%, respectively. Fourteen cases showed the complete resistance to the total 8 chemotherapy drugs. Furthermore, the expression of GRP78 was stronger in poorly differentiated cancer as compared with the well and moderately differentiated cancer (P < 0.05), so as in stage II and III cancer than in stage I cancer (P < 0.05). Spearman correlation assay showed that there was a correlation between the chemotherapeutics resistance to ADM, VP-16, VCR, TPT and the expression of GRP78 in NSCLC (P < 0.05).

CONCLUSIONSIt is feasible to detect the drug sensitivity to chemotherapy for tumor cells by MTT method. The results of chemosensitivity assay in vitro are indicative of clinical drug administration in NSCLC. The detection of GRP78 isalso indicative of the resistance to chemotherapy drugs and the differentiation and the clinical stage in NSCLC.

Objective To analyze the monitoring status of occupational hazard factors in key industry workplaces in a city of the Pearl River Delta area from 2019 to 2023. Methods A total of 1 548 enterprises in 12 key industries of the city were selected as the research subjects using the judgmental sampling method. Their monitoring data for dust, chemical factors, and noise, along with the occupational health management status of the enterprises were analyzed. Results Among the 1 548 enterprises, large and medium-sized enterprises accounted for 2.7% and 13.4%, while small and micro enterprises accounted for 83.9%. A total of 474 enterprises exceeded the national limit in the detection of occupational hazard factors, with an exceedance rate of 30.6%. The rates of workers exposed to occupational hazard factors, dust, chemical factors, and noise were 29.4%, 6.9%, 21.0%, and 13.0%, respectively, all showing a downward trend year by year (all P<0.05). The training rates for occupational health among enterprise managers, responsible persons, and workers were 84.1%, 84.2%, and 91.2%, respectively. The detection rates for abnormal occupational health examinations among workers exposed to dust, chemical factors, and noise were 0.2%, 0.3%, and 0.5%, respectively. The setting rates of warning signs and warning instructions among enterprises for dust, chemical toxins, and noise were 87.3%, 91.1%, and 89.5%, respectively. The setting rates for dust, toxic chemical, and noise control facilities were 72.4%, 75.4%, and 46.0%, with effectiveness rates of 70.5%, 56.6%, and 55.2%, respectively. The distribution rates of personal protective dust masks, gas masks, and noise earplugs/earmuffs were 91.9%, 83.8%, and 86.4%, with wearing rates of 80.8%, 70.5%, and 76.4%, respectively. The detection rates of exceeding national limits for dust, chemical factors, and noise in the work site of occupational hazard factors were15.2%, 1.0%, and 21.6%, respectively. The detection rates of exceeding national limits for dust, chemical factors, and noise in the workplace of occupational hazard factors were 2.4%, 2.5%, and 12.3%, respectively. The exceedance rate for noise in work site showed an upward trend year by year (P<0.01). Conclusion Occupational disease prevention and control work in the key industries of this city needs strengthening. It is essential to further enhance the regular monitoring and preventive measures of occupational hazard factors in enterprises, improve protective measures, strengthen the use of personal protective equipment, and enhance occupational health training and supervision, to effectively reduce the risk of occupational diseases and protect workers' occupational health rights.