KIF15 Promotes Progression of Castration Resistant Prostate Cancer by Activating EGFR Signaling Pathway

Identifying prognostic targets in metastatic prostate cancer beyond AR

Genome-wide screens using CRISPR/RNAi can identify new therapeutic vulnerabilities in prostate cancer. In this study, we combine DepMap functional screen data with a large gene expression database (N = 1012) and clinical outcomes to identify potentially druggable targets. Eight genes (CYC, CYP51A1, DHFR, EBP, KIF15, PPM1D, SQLE, and UMPS) demonstrated strong dependency in cell lines and were also associated with worse prognosis clinically, representing potential therapeutic targets in metastatic prostate cancer. Four of these (DHFR, EBP, KIF15, and PPM1D) demonstrated higher expression in neuroendocrine prostate cancer. Furthermore, all but one (KIF15) were not significantly decreased from pretreatment to posttreatment, suggesting that they may remain targetable postabiraterone therapy. All eight genes showed evidence of protein expression in prostate cancers or cell lines. These potentially druggable targets associated with prostate cancer cell line dependency and worse clinical outcomes have also demonstrated literature support as potential targets, supporting further research into their potential clinical relevance as therapeutic targets in prostate cancer.

Increased N-glycosylation of PSMA by GnT-V enhances tumor malignancy through interacting with JAK2 and the subsequent STAT3-mediated transcriptional activation in prostate cancer

Prostate-specific membrane antigen (PSMA), a membrane glycoprotein with high specificity, has emerged as an effective target for imaging and therapy in prostate cancer. Despite its potential, the role and molecular mechanism underlying PSMA glycosylation and overexpression remain to be fully clarified. In this study, we performed a comprehensive analysis of site-specific N-glycosylation patterns of PSMA, revealing that β1,6-GlcNAc branching at N121 and N336, catalyzed by GnT-V, is crucial for its expression. We found that the degradation of non-N-glycosylated PSMA predominantly occurs through the autophagy-lysosome pathway. Notably, androgen deprivation was shown to upregulate the expression of PSMA and GnT-V, simultaneously activating the transcription factor STAT3. Co-immunoprecipitation assay confirmed a direct interaction between PSMA and JAK2, which facilitates the activation of STAT3. This, in turn, drives the overexpression of PSMA and promotes its aberrant N-glycosylation, thereby advancing prostate cancer progression. Importantly, combined inhibition of STAT3 and N-glycosylation demonstrated a synergistic effect in reducing tumor viability. Our findings elucidate a novel positive feedback loop involving JAK2/STAT3/GnT-V/PSMA axis, contributing to the malignancy of prostate cancer and providing a foundation for innovative therapeutic strategies targeting this pathway.

Atractylenolide I ameliorated the growth and enzalutamide resistance of castration-resistant prostate cancer by targeting KIF15

BACKGROUND

Castration-resistant prostate cancer (CRPC) has been a major cause of tumor-associated death among men worldwide. The discovery of novel therapeutic medicines for CRPC remains imperative. Atractylenolide I (ATR-I), a prominent bioactive component from Atractylodes macrocephala, exhibits powerful anticancer potentials in various malignancies. Nevertheless, the ATR-I's activity on CRPC has not been reported.

METHODS

An enzalutamide-resistant (EnzR) cell line was successfully constructed. CCK-8, EdU, wound healing, Transwell assays, flow cytometry, and xenograft tumor models were applied to investigate the antitumor activity of ATR-I against CRPC. The changes in the gene expression profiles after ATR-I treatment were analyzed using RNA sequencing.

RESULTS

ATR-I suppressed the proliferative and migratory abilities of AR+ and AR- CRPC cells, while triggering cell cycle arrest and apoptosis. ATR-I also exerted anti-cancer activity on EnzR cell lines. Intriguingly, a combination of ATR-I with enzalutamide synergistically induced more apoptosis of tumor cells. RNA-sequencing identified kinesin family member 15 (KIF15) as a potential target of ATR-I. KIF15 was up-regulated in prostate cancer (PCa), and its higher level was associated with poorer clinical outcomes. Further investigation showed that ATR-I mediated ubiquitin-proteasomal degradation of AR/AR-V7 through targeting KIF15, resulting in CRPC repression. Finally, our in vivo experiment verified that ATR-I alone or in combination with enzalutamide retarded the growth of EnzR xenograft tumors.

CONCLUSIONS

These findings identified ATR-I as a promising therapeutic drug for overcoming enzalutamide resistance in CRPC patients and increased our understanding about its antitumor mechanisms.

Kif15 regulates Coro1a+ cell migration and phagocytosis in zebrafish after spinal cord injury

The role of immune cells is crucial in nerve regeneration following spinal cord injury. Kif15, a member of the kinesin family, has been shown to enhance macrophage phagocytosis. This study investigates the impact of Kif15 deficiency on immune cells in zebrafish with spinal cord injury. Using kif15 morphants in Tg(coro1a:EGFP) zebrafish, we observed increased recruitment of Coro1a+ cells to the injury site, followed by a rapid decline in kif15 morphants. Transcriptome analysis revealed that inflammatory and phagocytic signals were significantly enhanced at 1-hour post-injury (hpi), while MAPK pathways indicated growth at 24 hpi. Enhanced phagocytosis was confirmed using neutral red particles, and the Kif15 inhibitor GW406108X further supported increased migration and phagocytosis in macrophages. Activation of Cdc42 and RhoA was significantly increased, contributing to cell motility and phagocytosis. Additionally, the number of apoptotic cells was reduced in kif15 morphants, suggesting that Kif15 depletion could activate immune cells and efficiently remove apoptotic cells. Our study provides in vivo evidence that Kif15 is involved in immune cell migration and phagocytosis and suggests potential therapeutic roles for Kif15 inhibitors in spinal cord injury treatment.

Insufficient KIF15 during porcine oocyte ageing induces HDAC6-based microtubule instability

During aging, oocytes display cytoskeleton dynamics defects and aneuploidy, leading to embryonic aneuploidy, which in turn causes miscarriages, implantation failures, and birth defects. KIF15 (also known as Hklp2), a member of the kinesin-12 superfamily, is a cytoplasmic motor protein reported to be involved in Golgi and vesicle-related transport during mitosis in somatic cells. However, the regulatory mechanisms of KIF15 during meiosis in porcine oocytes and the connection with postovulatory aging remain unclear. In present study, we found that KIF15 is expressed during porcine oocyte maturation, and its localization is dependent on microtubule dynamics. Furthermore, the level of KIF15 expression decreased in postovulatory aged oocytes. The decrease in KIF15 blocked polar body extrusion, thereby hindering oocyte maturation. We demonstrated that KIF15 defects contributed to abnormal spindle morphologies and chromosome misalignment, possibly due to microtubule instability, as evidenced by microtubule depolymerization after cold treatment. Additionally, our data indicated that KIF15 modulates HDAC6 to affect tubulin acetylation in oocytes. Taken together, these results suggest that KIF15 regulates HDAC6-related microtubule stability for spindle organization in porcine oocytes during meiosis, which may contribute to the decline in maturation competence in aged porcine oocytes.

Cancer on motors: How kinesins drive prostate cancer progression?

Prostate cancer causes numerous male deaths annually. Although great progress has been made in the diagnosis and treatment of prostate cancer during the past several decades, much about this disease remains unknown, especially its pathobiology. The kinesin superfamily is a pivotal group of motor proteins, that contains a microtubule-based motor domain and features an adenosine triphosphatase activity and motility characteristics. Large-scale sequencing analyses based on clinical samples and animal models have shown that several members of the kinesin family are dysregulated in prostate cancer. Abnormal expression of kinesins could be linked to uncontrolled cell growth, inhibited apoptosis and increased metastasis ability. Additionally, kinesins may be implicated in chemotherapy resistance and escape immunologic cytotoxicity, which creates a barrier to cancer treatment. Here we cover the recent advances in understanding how kinesins may drive prostate cancer progression and how targeting their function may be a therapeutic strategy. A better understanding of kinesins in prostate cancer tumorigenesis may be pivotal for improving disease outcomes in prostate cancer patients.

PI3K/Akt signaling in urological cancers: Tumorigenesis function, therapeutic potential, and therapy response regulation

In addition to environmental conditions, lifestyle factors, and chemical exposure, aberrant gene expression and mutations involve in the beginning and development of urological tumors. Even in Western nations, urological malignancies are among the top causes of patient death, and their prevalence appears to be gender dependent. The prognosis for individuals with urological malignancies remains dismal and unfavorable due to the ineffectiveness of conventional treatment methods. PI3K/Akt is a popular biochemical mechanism that is activated in tumor cells as a result of PTEN loss. PI3K/Akt escalates growth and metastasis. Moreover, due to the increase in tumor cell viability caused by PI3K/Akt activation, cancer cells may acquire resistance to treatment. This review article examines the function of PI3K/Akt in major urological tumors including bladder, prostate, and renal tumors. In prostate, bladder, and kidney tumors, the level of PI3K and Akt are notably elevated. In addition, the activation of PI3K/Akt enhances the levels of Bcl-2 and XIAP, hence increasing the tumor cell survival rate. PI3K/Akt ] upregulates EMT pathways and matrix metalloproteinase expression to increase urological cancer metastasis. Furthermore, stimulation of PI3K/Akt results in drug- and radio-resistant cancers, but its suppression by anti-tumor drugs impedes the tumorigenesis.