Treatment of advanced non-small cell lung cancer with driver mutations: current applications and future directions

With the improved understanding of driver mutations in non-small cell lung cancer (NSCLC), expanding the targeted therapeutic options improved the survival and safety. However, responses to these agents are commonly temporary and incomplete. Moreover, even patients with the same oncogenic driver gene can respond diversely to the same agent. Furthermore, the therapeutic role of immune-checkpoint inhibitors (ICIs) in oncogene-driven NSCLC remains unclear. Therefore, this review aimed to classify the management of NSCLC with driver mutations based on the gene subtype, concomitant mutation, and dynamic alternation. Then, we provide an overview of the resistant mechanism of target therapy occurring in targeted alternations ("target-dependent resistance") and in the parallel and downstream pathways ("target-independent resistance"). Thirdly, we discuss the effectiveness of ICIs for NSCLC with driver mutations and the combined therapeutic approaches that might reverse the immunosuppressive tumor immune microenvironment. Finally, we listed the emerging treatment strategies for the new oncogenic alternations, and proposed the perspective of NSCLC with driver mutations. This review will guide clinicians to design tailored treatments for NSCLC with driver mutations.

Systematic Analysis of Tyrosine Kinase Inhibitor Response to RET Gatekeeper Mutations in Thyroid Cancer

The proto-oncogene protein RET is a receptor tyrosine kinase that plays an important role in the development and progress of various human cancers. Currently, targeting RET with small-molecule tyrosine kinase inhibitors (TKIs) has been established as promising therapeutic strategy for thyroid carcinoma (TC). However, two gatekeeper mutations V804M and V804L in RET kinase domain have been frequently observed to cause drug resistance during the targeted therapy, largely limiting the application of reversible TKIs in TC. Here, we described an integrative protocol that combined literature curation, computational analysis, and in vitro kinase assay to systematically investigate the response profile of 9 approved RET TKIs to the two clinical RET gatekeeper mutations. It was revealed that the two mutations exhibit a similar energetic behavior to influence TKI binding, which can moderately decrease competitive inhibitor affinity and modestly increase substrate ATP affinity simultaneously. However, the binding potency of few second-generation kinase inhibitors such as Ponatinib and Alectinib can be improved to overcome the increased ATP affinity, thus restoring their inhibitory activity against the kinase mutants. Subsequently, the established protocol was employed to investigate the response profile of 4 commercially available RET TKIs that are under preclinical or clinical development. Three out of the four TKIs were found to become resistant upon the mutations due to steric hindrance effect introduced by the mutated residues, while the remaining one was moderately sensitized by the mutations since the mutated residues can form additional hydrophobic and van der Waals interactions with the inhibitor.

Rational Design of an Orthogonal Molecular Interaction System at the Complex Interface of Lung Cancer-Related MDM2 Protein with p53 Peptide

The oncogenic protein MDM2 is an important negative regulator of p53 tumour suppressor. Overexpression of this protein is closely related to the pathological progression and metastasis of lung cancer and other tumours. Previously, a 12-mer peptide segment 17ETFSDLWKLLPE28 (p5317–28) corresponding to residues 17–28 of the human p53 transactivation domain was identified to interact moderately with MDM2. Here, we successfully created an orthogonal molecular interaction system between a native hydrogen bond (H-bond) and a designed halogen bond (X-bond) across the protein–peptide complex interface, where the X-bond was introduced by substituting the 3-hydrogen atom of the benzene ring of the p5317–28 Phe19 residue with a halogen atom X, resulting in a series of 3X-peptides (X = F, Cl, Br or I). Theoretical analysis found that chlorine is a good compromise between X-bonding strength and steric hindrance due to introducing a bulkier halogen atom to the tightly packed complex interface. Consequently, the 3Cl-peptide (Kd = 105 nM) was determined to exhibit ~5-fold affinity improvement relative to p5317–28 (Kd = 570 nM). In contrast, the binding affinity of the 2Cl-peptide (Kd = 492 nM), a negative control that cannot form the X-bond according to computational analysis, did not change considerably on the halogenation.