Efficacy of chemotherapy plus gefitinib treatment in advanced non-small-cell lung cancer patients following acquired resistance to gefitinib

Altered expression of programmed death-ligand 1 after neo-adjuvant chemotherapy in patients with lung squamous cell carcinoma

OBJECTIVE

Programmed death-ligand 1 (PD-L1) is known to be over-expressed in non-small cell lung cancer (NSCLC). However, the impact of chemotherapy on the altered status of PD-L1 expression has not been examined for NSCLC. The present study was intended to examine the impact of neoadjuvant chemotherapy on PD-L1 expression and its prognostic significance in lung squamous cell carcinoma (SCC).

PATIENTS AND METHODS

Matched tumor samples were obtained from 76 SCC patients prior to and after neoadjuvant chemotherapy. The expression of PD-L1 was evaluated by immunohistochemistry. Survival analysis was performed by the Kaplan-Meier method.

RESULTS

Prior to neoadjuvant chemotherapy, PD-L1 expression was identified in 52.6% (40/76) of SCC patients while 61.8% (47/76) were positive for PD-L1 expression after neoadjuvant chemotherapy. Nine patients switched from negative to positive while another two patients' samples showed the reverse of the above result. Multivariate analysis demonstrated that postoperative expression of PD-L1 was an independent prognostic factor for overall survival (HR=0.50, P=0.003), but not for PD-L1 expression prior to neoadjuvant chemotherapy.

CONCLUSION

Neoadjuvant chemotherapy may up-regulate the expression of PD-L1. As compared with the status of PD-L1 expression prior to chemotherapy, the postoperative expression of PD-L1 is a better prognostic factor for overall survival in SCC.

[Mechanism of Killing Effect of Thioridazine on Human Lung Cancer PC9 Cells]

背景与目的

硫利达嗪作为一种吩噻嗪类抗精神疾病药物，近期研究显示其在体外可抑制多种肿瘤细胞的增殖，但对肺癌的作用尚未见报道。本实验以PC9细胞株为研究对象，旨在观察硫利达嗪对其杀伤效应以及探讨其可能的作用机制。

方法

不同浓度的硫利达嗪作用PC9细胞后，四甲基偶氮唑蓝（methyl thiazolyltetrazolium, MTT）法检测细胞增殖率，流式细胞术检测细胞周期及细胞凋亡率，Western blot检测周期相关蛋白CyclinD1及凋亡相关蛋白Caspase-3、Caspase-8、Caspase-9、Bcl-2、Bax、Bcl-xl表达水平。

结果

硫利达嗪可显著抑制PC9细胞的增殖，其抑制作用呈时间和浓度依赖性。流式结果显示：随着硫利达嗪药物浓度的增高，细胞发生不同程度的G₀/G₁期阻滞，细胞凋亡率明显增高。各实验组与对照组比较，差异有统计学意义（P < 0.05）。Western blot结果显示：与对照组比较，实验组CyclinD1、Bcl-2、Bcl-xl表达水平明显下调（P < 0.01），Bax表达水平明显上调（P < 0.01），Caspase-3、Caspase-8、Caspase-9活性显著增加（P < 0.01）。

结论

硫利达嗪可显著抑制PC9细胞的增殖，其机制可能与其激活Caspase内外源性凋亡途径，下调CyclinD1、Bcl-2、Bcl-xl，上调Bax有关。

Methylation of RASSF1A and CDH13 genes in individualized chemotherapy for patients with non-small cell lung cancer

BACKGROUND

This study aimed to evaluate the methylation of RASSF1A and CDH13 gene promoter regions as a marker for monitoring chemotherapeutic efficacy with personalized medicine for patients with NSCLC, in the hope of providing a new direction for NSCLC individualized chemotherapy.

MATERIALS AND METHODS

42 NSCLC patients and 40 healthy controls were included. Patient blood samples were collected in the whole process of chemotherapy. Methylation of RASSF1A and CDH13 gene promoter regions was detected by the methylation specific polymerase chain reaction (MSP).

RESULTS

The rate of RASSF1A and CDH13 gene methylation in 42 cases of NSCLC patients was significantly higher than in 40 healthy controls (52.4% to 0.0%, 54.8% to 0.0%, p<0.05). After the chemotherapy, the hyper-methylation of RASSF1A and CDH13 genes in PR group and SD group decreased significantly (p<0.05), and was significantly different from that in PD group (p<0.05), but not as compared with healthy controls (P>0.05). With chemotherapy, RASSF1A and CDH13 promoter region methylation rate in 42 cases of patients showed a declining trend.

CONCLUSIONS

The methylation level of RASSF1A and CDH13 gene promoter region can reflect drug sensitivity of tumors to individualized treatment.