Unraveling the prevalence of various signalling pathways in non-small-cell lung cancer: a review

Cancer has become a huge public health issue all around the world. The focus of research is on innovative cancer therapy techniques that include the disease's unique targets. Among the cancer-related deaths that occur, lung cancer is considered to be one of the major, accounting for about 1.6 million fatalities globally in 2012, or nearly 20% of all cancer deaths. Non-small-cell lung cancer, a type of lung cancer comprises upto 84% of lung cancer cases, demonstrating the need for a more effective treatment. A novel category of cancer management, known as targeted cancer medicines, has risen to prominence in recent years. Targeted cancer treatments, like traditional chemotherapy, employ pharmacological drugs to slow cancer development, enhance cell death, and prevent it from spreading. Targeted treatments, as the name implies, work by interfering with particular proteins implicated in cancer. Numerous research conducted in the last several decades have led to the conclusion that signalling pathways are involved in the growth of lung cancer. All malignant tumours are produced, spread, invade, and behave in various abnormal ways due to abnormal pathways. Numerous significant signalling pathways, including the RTK/RAS/MAP-Kinase pathway (hence often referred to as RTK-RAS for simplicity), PI3K/Akt signalling, and others, have been discovered as commonly genetically changed. The current developments in research on various signalling pathways, as well as the underlying mechanisms of the molecules implicated in these pathways, are innovatively summarised in this review. To give a good sense of the study that has been done so far, many routes are placed together. Thus, this review includes the detailed description regarding each pathways, the mutations formed, and the present treatment strategy to overcome the resistance.

Therapeutic strategies for BRAF mutation in non-small cell lung cancer: a review

Lung cancer is the leading cause of cancer related deaths. Among the two broad types of lung cancer, non-small cell lung cancer accounts for 85% of the cases. The study of the genetic alteration has facilitated the development of targeted therapeutic interventions. Some of the molecular alterations which are important targets for drug therapy include Kirsten rat sarcoma (KRAS), Epidermal Growth Factor Receptor (EGFR), V-RAF murine sarcoma viral oncogene homolog B (BRAF), anaplastic lymphoma kinase gene (ALK). In the setting of extensive on-going clinical trials, it is imperative to periodically review the advancements and the newer drug therapies being available. Among all mutations, BRAF mutation is common with incidence being 8% overall and 1.5 - 4% in NSCLC. Here, we have summarized the BRAF mutation types and reviewed the various drug therapy available - for both V600 and nonV600 group; the mechanism of resistance to BRAF inhibitors and strategies to overcome it; the significance of comprehensive profiling of concurrent mutations, and the role of immune checkpoint inhibitor in BRAF mutated NSCLC. We have also included the currently ongoing clinical trials and recent advancements including combination therapy that would play a role in improving the overall survival and outcome of NSCLC.

In vitro and in vivo analyses on anti-NSCLC activity of apatinib: rediscovery of a new drug target V600E mutation

BACKGROUND

Apatinib (YN968D1) is the first small-molecule-targeting drug with anti-tumor activity created in China for the treatment of advanced gastric cancer (GC) and hepatocellular carcinoma (HCC). It showed significant variation in the efficacy for treating cancers, including advanced non-squamous non-small-cell lung cancer (NSCLC). Whether its efficacy could be optimized by subgrouping patients with certain genetic variation remains elusive.

METHODS

Here, we firstly used kinase screening to identify any possible target of apatinib against 138 kinases. The effects of apatinib on proliferation rates, cell cycle, cell apoptosis, and cell migration on cancer cell lines were analyzed; the in vitro potential pathways of apatinib on cancer cell lines were screened. The effect of apatinib on mouse cancer models in vivo was also analyzed.

RESULTS

Based on HCC364 cells with BRAF V600E mutation, we have shown that apatinib could inhibit their growth, migration, cell cycle, and induce their apoptosis. Based on mice with transplanted HCC364 cells, we have also shown that apatinib could inhibit the tumor growth. Based on immunohistochemistry, we have demonstrated that apatinib could suppress the phosphorylation of mitogen-activated protein kinase/extracellular signal-regulated kinase and extracellular regulated protein kinases. This may account at least part of the apatinib's inhibitory effect on HCC364 cancer cells.

CONCLUSIONS

BRAF V600E protein kinase is a target of apatinib by kinase screening. We have demonstrated that apatinib can effectively inhibit tumor cells with BRAF V600E mutation by in vitro and in vivo experiments. Our results have demonstrated that targeting BRAF V600E mutation, apatinib appears to be effective and safe for treating NSCLC and possibly other cancers with the same mutation.

Advances in anti-BRAF therapies for lung cancer

Non-small cell lung cancer (NSCLC) is one of the most frequent causes of mortality in the western world. v-raf murine sarcoma viral oncogene homolog B (BRAF) is a member of the Raf kinase family and plays a critical role in cellular growth, proliferation, and differentiation through the mitogen-activated protein kinase pathway. The incidence of BRAF mutations in NSCLC is low, accounting for 0-3% of all cases of lung cancer. Given the results obtained in metastatic melanoma, several studies have reported the efficacy of anti-BRAF therapies in NSCLC treatment. In this review, we describe changes in the landscape of BRAF-mutated lung cancer treatment and analyze insights from major clinical trials in the context of future therapeutic prospects.

BRAF in non-small cell lung cancer (NSCLC): Pickaxing another brick in the wall

Molecular characterization of non-small cell lung cancer (NSCLC) marked an historical turning point for the treatment of lung tumors harboring kinase alterations suitable for specific targeted drugs inhibition, translating into major clinical improvements. Besides EGFR, ALK and ROS1, BRAF represents a novel therapeutic target for the treatment of advanced NSCLC. BRAF mutations, found in 1.5-3.5% of NSCLC, are responsible of the constitutive activation of mitogen activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK) pathway. Clinical trials evaluating the efficacy of the BRAF inhibitor dabrafenib in combination with the downstream MEK inhibitor trametinib in metastatic BRAF^V600E-mutated NSCLC guaranteed FDA and EMA rapid approval of the combination regimen in this clinical setting. In line with the striking results observed in metastatic melanoma harboring the same molecular alteration, BRAF and MEK inhibition should be considered a new standard of care in this molecular subtype of NSCLC. In the present review, we propose an overview of the available evidence about BRAF in NSCLC mutations (V600E and non-V600E), from biological significance to emerging clinical implications of BRAF mutations detection. Focusing on the current strategies to act against the mutated kinase, we moreover approach additional strategies to overcome treatment resistance.