First-line gemcitabine plus cisplatin in nonsmall cell lung cancer patients

p21 promotes gemcitabine tolerance in A549 cells by inhibiting DNA damage and altering the cell cycle

Gemcitabine is one of the most widely used chemotherapy drugs for advanced malignant tumors, including non-small cell lung cancer. However, the clinical efficacy of gemcitabine is limited due to drug resistance. The aim of the present study was to investigate the role of p21 in gemcitabine-resistant A549 (A549/G+) lung cancer cells. IC50 values were determined using a Cell Counting Kit-8 (CCK-8) assay. mRNA and protein expression levels of genes were measured by reverse transcription-quantitative PCR and western blotting, respectively. The cell cycle distribution and apoptosis rate were analyzed by flow cytometry. DNA damage in cells was evaluated by single-cell gel electrophoresis. The results of western blot analysis and the CCK-8 assay demonstrated that the expression of p21 was higher in A549/G+ cells than in gemcitabine-sensitive cells. Knockdown of p21 expression in gemcitabine-resistant cells sensitized these cells to gemcitabine (with the IC50 decreasing from 84.2 to 26.7 µM). Cell cycle analysis revealed different changes in the cell cycle distribution in A549/G+ cells treated with the same concentration of gemcitabine, and decreased expression of p21 was shown to promote G1 arrest. The apoptosis assay and comet assay results revealed that decreased p21 expression resulted in accumulation of unrepaired DNA double-strand breaks (DSBs) and induction of apoptosis by gemcitabine. The present study demonstrated that knockout of p21 mRNA expression in A549/G+ cells promotes apoptosis and DNA DSB accumulation, accompanied by G1 arrest. These results indicated that p21 is involved in regulating the response of A549 cells to gemcitabine.

Gemcitabine‑fucoxanthin combination in human pancreatic cancer cells

Gemcitabine is a chemotherapeutic agent for pancreatic cancer treatment. It has also been demonstrated to inhibit human pancreatic cancer cell lines, MIA PaCa-2 and PANC-1. The aim of the present study was to investigate the suppressive effect of fucoxanthin, a marine carotenoid, in combination with gemcitabine on pancreatic cancer cells. MTT assays and cell cycle analysis using flow cytometry were performed to study the mechanism of action. The results revealed that combining a low dose of fucoxanthin with gemcitabine enhanced the cell viability of human embryonic kidney cells, 293, while a high dose of fucoxanthin enhanced the inhibitory effect of gemcitabine on the cell viability of this cell line. In addition, the enhanced effect of fucoxanthin on the inhibitory effect of gemcitabine on PANC-1 cells was significant (P<0.01). Fucoxanthin combined with gemcitabine also exerted significant enhancement of the anti-proliferation effect in MIA PaCa-2 cells in a concentration dependent manner (P<0.05), compared with gemcitabine treatment alone. In conclusion, fucoxanthin improved the cytotoxicity of gemcitabine on human pancreatic cancer cells at concentrations that were not cytotoxic to non-cancer cells. Thus, fucoxanthin has the potential to be used as an adjunct in pancreatic cancer treatment.

The Validity and Predictive Value of Blood-Based Biomarkers in Prediction of Response in the Treatment of Metastatic Non-Small Cell Lung Cancer: A Systematic Review

With the introduction of targeted therapies and immunotherapy, molecular diagnostics gained a more profound role in the management of non-small cell lung cancer (NSCLC). This study aimed to systematically search for studies reporting on the use of liquid biopsies (LB), the correlation between LBs and tissue biopsies, and finally the predictive value in the management of NSCLC. A systematic literature search was performed, including results published after 1 January 2014. Articles studying the predictive value or validity of a LB were included. The search (up to 1 September 2019) retrieved 1704 articles, 1323 articles were excluded after title and abstract screening. Remaining articles were assessed for eligibility by full-text review. After full-text review, 64 articles investigating the predictive value and 78 articles describing the validity were included. The majority of studies investigated the predictive value of LBs in relation to therapies targeting the epidermal growth factor receptor (EGFR) or anaplastic lymphoma kinase (ALK) receptor (n = 38). Of studies describing the validity of a biomarker, 55 articles report on one or more EGFR mutations. Although a variety of blood-based biomarkers are currently under investigation, most studies evaluated the validity of LBs to determine EGFR mutation status and the subsequent targeting of EGFR tyrosine kinase inhibitors based on the mutation status found in LBs of NSCLC patients.

The Role of Prostaglandin-Endoperoxide Synthase-2 in Chemoresistance of Non-Small Cell Lung Cancer

The prostaglandin-endoperoxide synthase-2 (PTGS2) plays essential roles in diverse pathological process. Although recent studies implied that PTGS2 was closely related with chemoresistance, the precise roles and the underlying mechanisms of PTGS2 in the developing process of chemoresistance in non-small cell lung cancer (NSCLC) remained elusive. In the present study, we revealed a novel molecular mechanism of PTGS2 implicated in the chemoresistance of NSCLC and proposed a model for the positive feedback regulation of PTGS2 in the process of developing resistance phenotype in NSCLC cells. Our results demonstrated that cisplatin induced PTGS2 expression through the ROS-ERK1/2-NF-κB signaling axis. The prostaglandin E2 (PGE2) derived from PTGS2 catalyzation further strengthened PTGS2 expression via the PGE2-EPs-ERK1/2 positive feedback loop, which induced multidrug resistance of NSCLC cells through up-regulation of BCL2 expression and the subsequent attenuation of cell apoptosis. Consistently, high levels of both PTGS2 and BCL2 were closely associated with poor survival in NSCLC patients. Inhibition of PTGS2 significantly reversed the chemoresistance in the resistant NSCLC in vitro and in vivo. Our results suggested that PTGS2 might be employed as an adjunctive therapeutic target for improving the response to the therapeutic agents in a subset of resistant NSCLC.

Alantolactone enhances gemcitabine sensitivity of lung cancer cells through the reactive oxygen species-mediated endoplasmic reticulum stress and Akt/GSK3β pathway

Lung cancer is one of the leading causes of cancer-associated mortality in China and globally. Gemcitabine (GEM), as a first-line therapeutic drug, has been used to treat lung cancer, but GEM resistance poses a major limitation on the efficacy of GEM chemotherapy. Alantolactone (ALT), a sesquiterpene lactone compound isolated from Inula helenium, has been identified to exert anticancer activity in various types of cancer, including breast, pancreatic, lung squamous and colorectal cancer. However, the underlying mechanisms of the anticancer activity of ALT in lung cancer remain to be fully elucidated. The present study aimed to determine whether ALT enhances the anticancer efficacy of GEM in lung cancer cells and investigated the underlying mechanisms. The cell viability was assessed with a Cell Counting Kit-8 assay. The cell cycle, apoptosis and the level of reactive oxygen species (ROS) were assessed by flow cytometry, and the expression of cell cycle-associated and apoptosis-associated proteins were determined by western blot analysis. The results demonstrated that ALT inhibited cell growth and induced S-phase arrest and cell apoptosis in A549 and NCI-H520 cells. Furthermore, ALT increased the level of ROS, inhibited the Akt/glycogen synthase kinase (GSK)3β pathway and induced endoplasmic reticulum (ER) stress in A549 and NCI-H520 cells. Additionally, ALT treatment sensitized lung cancer cells to GEM. Analysis of the molecular mechanisms further revealed that ALT enhanced the anticancer effects of GEM via ROS-mediated activation of the Akt/GSK3β and ER stress pathways. In conclusion, combined treatment with ALT and GEM may have potential as a clinical strategy for lung cancer treatment.

Influence of body mass index on the therapeutic efficacy of gemcitabine plus cisplatin and overall survival in lung squamous cell carcinoma

Background

Gemcitabine plus cisplatin (GP) is commonly used to treat lung squamous cell carcinoma (SCC); however, it is not clear which subgroup of lung SCC patients could benefit most from GP treatment. We explored the predictive factors in lung SCC patient cohorts.

Methods

Seventy‐eight lung SCC patients treated with a first‐line GP regimen were enrolled in this retrospective cohort study. Progression‐free survival (PFS) and overall survival (OS) were estimated using the Kaplan–Meier method. Classification tree models were used to explore the risk factors for PFS and OS in these patients.

Results

The median PFS and OS in SCC patients treated with a GP regimen were 6.0 and 13.6 months, respectively. Three terminal subgroups were formed for both PFS and OS. The subgroup with a body mass index (BMI) > 23.94 kg/m² and aged ≤ 54.5 had the longest PFS (9.0 months); the subgroup with a BMI < 23.94  kg/m² and aged ≤ 54.5 had the shortest PFS (4.05 months). Patients with an objective response (partial or complete response) to treatment had the longest OS (20.0 months), while patients with a BMI ≤ 26.92 kg/m² and stable or progressive disease as the best response had the shortest OS (11.2 months).

Conclusions

BMI and age may be predictors of PFS in lung SCC patients who receive GP treatment. BMI and best response to GP treatment predicts OS in such patients. Patients’ clinical pathological characteristics may be used to predict the therapeutic efficacy of chemotherapy and survival.

Advanced squamous lung carcinoma in a patient experiencing long-term survival following repeated responses to gemcitabine and cisplatin chemotherapy: A case report

The cisplatin and gemcitabine regimen is one of the most effective regimens against advanced non-small-cell lung cancer. However, tumors that are initially sensitive to chemotherapy treatment may acquire drug resistance. Excision repair cross complementation 1 gene (ERCC1) is involved in the repair of DNA damage caused by cisplatin, and ribonucleotide reductase M1 subunit (RRM1) is associated with gemcitabine resistance in tumor cells. The current study reports the case of a patient with advanced squamous cell lung carcinoma exhibiting low ERCC1 and RRM1 expression levels, who experienced long-term survival following repeated responses to gemcitabine and cisplatin chemotherapy. This case indicates that selected patients may benefit from multiple courses of gemcitabine and cisplatin chemotherapy, and the sustained clinical benefits suggest that further investigation into individualized therapy is merited.

[Role of RRM1 in the Treatment and Prognosis of Advanced Non-small Cell Lung Cancer]

Lung cancer is one of the most common and highest mortality rates malignant tumors, further, 75%-80% is non-small cell lung cancer (NSCLC). For the majority of patients, lost the chance of radical operation or radiotherapy, chemotherapy is the main treatment. However, because of the diversities of tumor behavior and drug-resistant, the chemotherapy of advanced NSCLC is not optimistic. In recent years, with the application of molecular markers for individual chemotherapy, these patients have achieved prolong life and improved life quality. Individualized chemotherapy based on molecular markers to select the appropriate drug is the problem that needs to be solved. The paper gives a brief review on the role of ribonucleotide reductase subunit 1 (RRM1) in the treatment and prognosis of advanced NSCLC. Individualized chemotherapy by RRM1 can't become commonplace for advanced NSCLC and needs further research.