Serum β-klotho is a potential biomarker in the prediction of clinical outcomes among patients with NSCLC

Comparing Western and traditional Chinese medicine for male sexual dysfunction: can Klotho represent a silk road?

Traditional Chinese medicine (TCM) and Western Medicine both have shown efficacy in treating male sexual dysfunction (MSD). The aim of this perspective paper is to discuss a possible link between Western medicine and TCM in the MSD field as represented by the entity of Klotho. Klotho is a recently discovered protein, mainly expressed in the kidney, encoded by the anti-aging gene klotho. Not only is Klotho significantly correlated with the development and progression of kidney diseases and their complications, but increasing evidence indicates that it is also closely related to MSD. A comprehensive search within PubMed database was performed to retrieve available evidence on Klotho's roles, particularly in kidney and in MSD. Indeed, in the TCM theory, the concept of the "kidney" is entirely different from the Western medicine: it is closely related to metabolism and to the reproductive, nervous, endocrine systems, being more than just a urinary organ. According to the "Kidney storing essence (jīng) and governing reproduction" (KSEGR) theory, a cornerstone in TCM, the treatment of MSD mainly consists of restoring the kidney's function. Signs of decreasing kidney essence show a consistent similarity to deficiencies of Klotho, also for what regards the male sexual function. Based on the current evidence, Klotho may represent a potential biological indicator for sexual desire and sexual function and a kind of new scientific Silk Road between TCM and Western medicine for MSD; nevertheless, there is a need to conduct further high-quality research to prove this hypothesis.

Development and validation of a predictive model based on β-Klotho for head and neck squamous cell carcinoma

Head and neck epithelial tissue tumors may be identified as head and neck squamous cell carcinoma (HNSC). Numerous malignancies are encouraged by dysregulation of the FGF19-β-Klotho (KLB) axis in the tumor microenvironment. Using protein databases and RT-qPCR, we examined KLB expression in HNSC. In HNSC, higher KLB expression was linked to longer survival times and better prognoses. Furthermore, variations in drug susceptibility and immunological infiltration were noted according to KLB expression levels. These results underscore the importance of KLB in the course and management of HNSC by indicating that it may function as a possible prognostic marker and influence immunological and therapeutic responses in these individuals. Further study on HNSC is necessary to investigate KLB's potential as a therapeutic target and prognostic indicator.

Protein interaction networks characterizing the A549 cells Klotho transfected are associated with activated pro-apoptotic Bim and suppressed Wnt/β-catenin signaling pathway

Invasive assays and lung tumor-bearing mice models using a human lung adenocarcinoma cell line A549 cells transfected with the Klotho (KL) gene, A549/KL cells, have confirmed that KL suppresses invasive/metastatic potential. This study aimed to identify the co-expression protein networks and proteomic profiles associated with A549/KL cells to understand how Klotho protein expression affects molecular networks associated with lung carcinoma malignancy. A two-step application of a weighted network correlation analysis to the cells' quantitative proteome datasets of a total of 6,994 proteins, identified by mass spectrometry-based proteomic analysis with data-independent acquisition (DIA), identified one network module as most significantly associated with the A549/KL trait. Upstream analyses, confirmed by western blot, implicated the pro-apoptotic Bim (Bcl-2-like protein 11) as a master regulator of molecular networks affected by Klotho. GeneMANIA interaction networks and quantitative proteome data implicated that Klotho interacts with two signaling axes: negatively with the Wnt/β-catenin axis, and positively by activating Bim. Our findings might contribute to the development of future therapeutic strategies.

Klotho in Cancer: Potential Diagnostic and Prognostic Applications

Klotho proteins, αKlotho, βKlotho, and γKlotho, exert tumor-suppressive activities via the fibroblast growth factor receptors and multiple cell-signaling pathways. There is a growing interest in Klotho proteins as potential diagnostic and prognostic biomarkers for multiple diseases. However, recent advances regarding their roles and potential applications in cancer remain disperse and require an integrated analysis. The present review analyzed research articles published between 2012 and 2022 in the Cochrane and Scopus scientific databases to study the role of Klotho in cancer and their potential as tools for diagnosing specific cancer types, predicting tumor aggressiveness and prognosis. Twenty-six articles were selected, dealing with acute myeloid leukemia and with bladder, breast, colorectal, esophageal, gastric, hepatocellular, ovarian, pancreatic, prostatic, pulmonary, renal, and thyroid cancers. αKlotho was consistently associated with improved prognosis and may be useful in estimating patient survival. A single study reported the use of soluble αKlotho levels in blood serum as a tool to aid the diagnosis of esophageal cancer. γKlotho was associated with increased aggressiveness of bladder, breast, and prostate cancer, and βKlotho showed mixed results. Further clinical development of Klotho-based assays will require careful identification of specific tumor subtypes where Klotho proteins may be most valuable as diagnostic or prognostic tools.

Klotho-beta attenuates Rab8a-mediated exosome regulation and promotes prostate cancer progression

Tumor-secreted exosomes have a wide range of effects on the growth, metastasis, and drug resistance of cancer cells. However, whether and how the molecular mechanisms that regulate the secretion of exosomes could affect tumor progression remains poorly understood. Klotho beta (KLB) has been reported dysregulated in prostate cancer, but its function remains unknown. Herein, we first determined that KLB was upregulated in prostate cancer and its expression level was positively correlated with prostate cancer malignant phenotype both in vitro and in vivo. Intriguingly, KLB overexpression could impair the release of exosomes and cause the intracellular accumulation of multivesicular bodies (MVBs) in prostate cancer cells. Mechanistically, KLB attenuated exosomes secretion through a Rab8a-dependent pathway. Rab8a was downregulated in KLB overexpressing cells whereas overexpression of Rab8a could rescue the impaired release of exosomes and attenuate the KLB-induced malignant phenotype of prostate cancer both in vitro and in vivo. Taken together, this study has unveiled the tumor-promoting role of KLB mediated by its regulation on exosomes secretion through a Rab8a-dependent mechanism. These findings could be exploited to develop novel theranostic targets for prostate cancer.

Identification of Six Prognostic Genes in EGFR-Mutant Lung Adenocarcinoma Using Structure Network Algorithms

This study aims to determine hub genes related to the incidence and prognosis of EGFR-mutant (MT) lung adenocarcinoma (LUAD) with weighted gene coexpression network analysis (WGCNA). From The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases, we used 253 EGFR-MT LUAD samples and 38 normal lung tissue samples. At the same time, GSE19188 was additionally included to verify the accuracy of the predicted gene. To discover differentially expressed genes (DEGs), the R package “limma” was used. The R packages “WGCNA” and “survival” were used to perform WGCNA and survival analyses, respectively. The functional analysis was carried out with the R package “clusterProfiler.” In total, 1450 EGFR-MT–specific DEGs were found, and 7 tumor-related modules were marked with WGCNA. We found 6 hub genes in DEGs that overlapped with the tumor-related modules, and the overexpression level of B3GNT3 was significantly associated with the worse OS (overall survival) of the EGFR-MT LUAD patients (p < 0.05). Functional analysis of the hub genes showed the metabolism and protein synthesis–related terms added value. In conclusion, we used WGCNA to identify hub genes in the development of EGFR-MT LUAD. The established prognostic factors could be used as clinical biomarkers. To confirm the mechanism of those genes in EGFR-MT LUAD, further molecular research is required.