Salvage treatment with irinotecan/cisplatin versus pemetrexed/cisplatin in patients with non-small cell lung cancer pre-treated with a non-platinum-based regimen in the first-line setting: a randomized phase II study of the Hellenic Oncology Research Group (HORG)

MicroRNAs as the critical regulators of autophagy-mediated cisplatin response in tumor cells

Chemotherapy is one of the most common therapeutic methods in advanced and metastatic tumors. Cisplatin (CDDP) is considered as one of the main first-line chemotherapy drugs in solid tumors. However, there is a high rate of CDDP resistance in cancer patients. Multi-drug resistance (MDR) as one of the main therapeutic challenges in cancer patients is associated with various cellular processes such as drug efflux, DNA repair, and autophagy. Autophagy is a cellular mechanism that protects the tumor cells toward the chemotherapeutic drugs. Therefore, autophagy regulatory factors can increase or decrease the chemotherapy response in tumor cells. MicroRNAs (miRNAs) have a pivotal role in regulation of autophagy in normal and tumor cells. Therefore, in the present review, we discussed the role of miRNAs in CDDP response through the regulation of autophagy. It has been reported that miRNAs mainly increased the CDDP sensitivity in tumor cells by inhibition of autophagy. PI3K/AKT signaling pathway and autophagy-related genes (ATGs) were the main targets of miRNAs in the regulation of autophagy-mediated CDDP response in tumor cells. This review can be an effective step to introduce the miRNAs as efficient therapeutic options to increase autophagy-mediated CDDP sensitivity in tumor cells.

LINC00963: A potential cancer diagnostic and therapeutic target

Long intergenic noncoding RNA 00963 (LINC00963) is located on human chromosome 9q34.11. Aberrantly expressed LINC00963 often exerts oncogenic effects by regulating various cellular processes including proliferation, migration, invasion, EMT, and apoptosis. Overexpressed LINC00963 is associated with cancer clinicopathological features and poor cancer prognosis, and can be used in the diagnosis of hepatocellular carcinoma. LINC00963 can build a complex ceRNA network by competitively binding to 22 miRNAs in 14 cancers. LINC00963 can also directly regulate four downstream protein-coding genes. Specifically, LINC00963 promotes the transition of prostate cancer from an androgen-dependent mode to an androgen-independent mode by participating in the transactivation of EGFR. LINC00963 can bind EZH2 and inhibit p21 expression, thereby promoting glioma cell proliferation and invasion. In non-small cell lung cancer, LINC00963 can recruit NONO and CRTC, forming a positive feedback loop of LINC00963/NONO/CRTC/CREB/LINC00963, thereby promoting cancer cell metastasis. LINC00963 is involved in the PI3K/AKT signaling pathway, Wnt signaling pathway, AMPK signaling pathway, and MAPK signaling pathway. Furthermore, LINC00963 is associated with drug resistance in oral squamous cell carcinoma (cisplatin and 5-fluorouracil) and gastric cancer (oxaliplatin) and predicts neoadjuvant efficacy of taxane-anthracyclines in breast cancer. This work systematically reviewed the clinical value of abnormal expression of LINC00963 in various tumors, demonstrated the complex molecular mechanism of LINC00963, and provided directions for future related research.

MicroRNA-25-3p promotes cisplatin resistance in Non-small-cell lung carcinoma (NSCLC) through adjusting PTEN/PI3K/AKT route

MicroRNAs exert crucial effects in the drug resistance. The purpose of this research was to investigate the miR-25-3p effects on DDP resistance in NSCLC. We used RT-qPCR to evaluate the expression of miR-25-3p. Cell growth was determined using MTS assay. Cellular bio-activity was analyzed via Colony formation, Annexin V/PI, and Transwell assay. Luciferase reporter assay was used to determine miR-25-3p and PTEN binding. Western blot was used to determine PTEN, PI3K, p-AKT/AKT expression. In-vivo study was used to determine the effects of miR-25-3p on the tumor growth. Expression of miR-25-3p is increased in NSCLC cisplatin resistant A549 and H1299 cells. Furthermore, miR-25-3p mimic enhanced drug resistance, and accelerated cell invasion and metastasis. Moreover, miR-25-3p mimic resulted in the activation of PTEN/PI3K/AKT pathway. However, miR-25-3p inhibitors exhibited the opposite trend. We further identified PTEN as a potential target of miR-25-3p. PTEN knockout promoted cisplatin resistance, while PTEN mimic displayed opposite effects. Interestingly, miR-25-3p further boosted cisplatin resistance cells in vivo, and miR-25-3p inhibitors reduced the in-vivo tumor volume. MiR-25-3p/PTEN/PI3K/AKT axis might accelerate DDP tolerance in NSCLC, which may serve as a potential target for chemotherapy resistance in NSCLC.

First and Second Line Chemotherapeutic Regimens for Non-Small Cell Lung Carcinomas - The Efficacy of Platinum, Non-Platinum and Combination Therapy: A Literature Review

Non-small cell lung carcinomas (NSCLC) account for a major part of all lung cancer diagnoses. The current literature review is aimed to analyze the varied chemotherapeutic treatment regimens available and to provide a standard for their use in the present and future scenarios. The current literature review focuses on platinum, non-platinum and combination therapeutic modalities, in the first and second line setting. The review also ensures that docetaxel and/or gemcitabine is a part of the study. A PubMed search for NSCLC identified 70,077 articles. A total of 36 research articles were obtained following the application of keywords and inclusion/exclusion criteria to narrow down our search to meet with the research objective. These articles consider NSCLC and chemotherapeutic treatment modalities as its primary endpoint. These 36 articles included 15 randomized clinical trials, five randomized control trials, five retrospective cohort studies, one case-control study, six review articles and four observational studies. Our analysis shows that there is an increasing potential for the use of non-platinum based drugs in the clinical setting with an efficacy that is at par with that of platinum-based treatment modalities. In fact, the studies have proven a greater advantage with the use of combination therapy (non-platinum + platinum), which can be readily applied as an alternative in the clinical setting while the use of non-platinum drugs (other than docetaxel) as a monotherapy or in combination with other non-platinum based drugs does require further research.

A Novel Camptothecin Derivative 3j Inhibits Nsclc Proliferation Via Induction of Cell Cycle Arrest By Topo I-Mediated DNA Damage

OBJECTIVE

The aim of this study is to investigate the inhibitory effect of camptothecin derivative 3j on Non-Small Cell Lung Cancer (NSCLCs) cells and the potential anti-tumor mechanisms.

BACKGROUND

Camptothecin compounds are considered as the third largest natural drugs which are widely investigated in the world and they suffered restriction because of serious toxicity, such as hemorrhagic cystitis and bone marrow suppression.

METHODS

Using cell proliferation assay and S180 tumor mice model, a series of 20(S)-O-substituted benzoyl 7- ethylcamptothecin compounds were screened and evaluated the antitumor activities in vitro and in vivo. Camptothecin derivative 3j was selected for further study using flow cytometry in NSCLCs cells. Cell cycle related protein cyclin A2, CDK2, cyclin D and cyclin E were detected by Western Blot. Then, computer molecular docking was used to confirm the interaction between 3j and Topo I. Also, DNA relaxation assay and alkaline comet assay were used to investigate the mechanism of 3j on DNA damage.

RESULTS

Our results demonstrated that camptothecin derivative 3j showed a greater antitumor effect in eleven 20(S)-O-substituted benzoyl 7-ethylcamptothecin compounds in vitro and in vivo. The IC50 of 3j was 1.54± 0.41 µM lower than irinotecan with an IC50 of 13.86±0.80 µM in NCI-H460 cell, which was reduced by 8 fold. In NCI-H1975 cell, the IC50 of 3j was 1.87±0.23 µM lower than irinotecan (IC50±SD, 5.35±0.38 µM), dropped by 1.8 fold. Flow cytometry analysis revealed that 3j induced significant accumulation in a dose-dependent manner. After 24h of 3j (10 µM) treatment, the percentage of NCI-H460 cell in S-phase significantly increased (to 93.54 ± 4.4%) compared with control cells (31.67 ± 3.4%). Similarly, the percentage of NCI-H1975 cell in Sphase significantly increased (to 83.99 ± 2.4%) compared with control cells (34.45 ± 3.9%) after treatment with 10µM of 3j. Moreover, increased levels of cyclin A2, CDK2, and decreased levels of cyclin D, cyclin E further confirmed that cell cycle arrest was induced by 3j. Furthermore, molecular docking studies suggested that 3j interacted with Topo I-DNA and DNA-relaxation assay simultaneously confirmed that 3j suppressed the activity of Topo I. Research on the mechanism showed that 3j exhibited anti-tumour activity via activating the DNA damage response pathway and suppressing the repair pathway in NSCLC cells.

CONCLUSION

Novel camptothecin derivative 3j has been demonstrated as a promising antitumor agent and remains to be assessed in further studies.

miR-181 regulates cisplatin-resistant non-small cell lung cancer via downregulation of autophagy through the PTEN/PI3K/AKT pathway

A number of miRNAs have been found to be abnormally expressed or mutated in numerous cancers and thus, are considered to act as oncogenes or tumor suppressor genes. The aim of the present study was to investigate the effect of miR-181 on cisplatin-resistant non-small cell lung cancer (NSCLC). In patients with cisplatin-resistant NSCLC, miR-181 expression was found to be markedly decreased. In addition, in the cisplatin-resistant human lung adenocarcinoma cell line A549/DDP, miR-181 downregulation promoted cell growth and metastasis and inhibited cell apoptosis, whereas miR-181 overexpression exerted the opposite effects. Furthermore, miR-181 downregulation suppressed LC3 and ATG5 protein expression in A549/DDP cells through suppression of the PTEN/PI3K/AKT/mTOR pathway, whereas miR-181 overexpression recovered LC3 and ATG5 protein expression by promoting PTEN/PI3K/AKT/mTOR signaling. In turn, PTEN inhibitors reduced the anticancer effects of miR-181 overexpression on A549/DDP cell growth via the regulation of autophagy through the PI3K/AKT/mTOR pathway. Therefore, miR-181 may be a novel and important regulator of cisplatin-resistant NSCLC by serving a role in the regulation of apoptosis, as an established rate-limiting miRNA target.