PAK4 inhibition significantly potentiates Gemcitabine activity in PDAC cells via inhibition of Wnt/β-catenin, p-ERK/MAPK and p-AKT/PI3K pathways

Utilizing TP53 hotspot mutations as effective predictors of gemcitabine treatment outcome in non-small-cell lung cancer

TP53 mutations are recognized to correlate with a worse prognosis in individuals with non-small cell lung cancer (NSCLC). There exists an immediate necessity to pinpoint selective treatment for patients carrying TP53 mutations. Potential drugs were identified by comparing drug sensitivity differences, represented by the half-maximal inhibitory concentration (IC50), between TP53 mutant and wild-type NSCLC cell lines using database analysis. In addition, clinical data from NSCLC patients were collected to evaluate both their TP53 status and their response to gemcitabine, thereby facilitating further validation. Subsequently, NSCLC cell lines with different TP53 status (A549 and H1299) were subjected to gemcitabine treatment to investigate the association between TP53 mutations and gemcitabine response. According to the dataset, NSCLC cell lines carrying TP53 mutations displayed heightened sensitivity to gemcitabine. From a clinical standpoint, patients exhibiting TP53 hotspot mutations demonstrated prolonged overall survival upon gemcitabine treatment. In vitro, overexpressing various hotspot TP53 mutations significantly sensitized H1299 cells to gemcitabine. Moreover, the knockdown of TP53 in A549 cells notably augmented sensitivity to gemcitabine treatment, as evidenced by cell viability and reproductive cell death assays. Conversely, the overexpression of wild-type TP53 in H1299 cells led to an increased resistance against gemcitabine. Gemcitabine is a treatment option for patients with non-small cell lung cancer (NSCLC) who carry TP53 hotspot mutations. This potential effectiveness might arise from its ability to disrupt DNA damage repair processes, leading to G2/M phase cell cycle arrest or an augmentation of mitotic abnormalities, eventually cause cell death. As a result, when planning treatment strategies for NSCLC patients possessing TP53 hotspot mutations, gemcitabine should be considered to incorporate into the indication.

Channeling Nicotinamide Phosphoribosyltransferase (NAMPT) to Address Life and Death

Nicotinamide phosphoribosyltransferase (NAMPT) catalyzes the rate-limiting step in NAD+ biosynthesis via salvage of NAM formed from catabolism of NAD+ by proteins with NADase activity (e.g., PARPs, SIRTs, CD38). Depletion of NAD+ in aging, neurodegeneration, and metabolic disorders is addressed by NAD+ supplementation. Conversely, NAMPT inhibitors have been developed for cancer therapy: many discovered by phenotypic screening for cancer cell death have low nanomolar potency in cellular models. No NAMPT inhibitor is yet FDA-approved. The ability of inhibitors to act as NAMPT substrates may be associated with efficacy and toxicity. Some 3-pyridyl inhibitors become 4-pyridyl activators or "NAD+ boosters". NAMPT positive allosteric modulators (N-PAMs) and boosters may increase enzyme activity by relieving substrate/product inhibition. Binding to a "rear channel" extending from the NAMPT active site is key for inhibitors, boosters, and N-PAMs. A deeper understanding may fulfill the potential of NAMPT ligands to regulate cellular life and death.