OBJECTIVE: This study aimed to describe the clinical and genetic characteristics of Chinese patients with congenital fibrosis of the extraocular muscles (CFEOM), and to evaluate the phenotype-genotype correlations in these patients.
METHODS: This was a retrospective study. Patients with CFEOM underwent detailed ophthalmic examinations and magnetic resonance imaging (MRI). Panel-based next-generation sequencing was performed to identify pathogenic variants of disease-causing genes.
RESULTS: Sixty-two patients with CFEOM were recruited into this study. Thirty-nine patients were diagnosed with CFEOM1 and 23 with CFEOM3. Forty-nine of the 62 patients with CFEOM carried either KIF21A (41/49) or TUBB3 variants (8/49). Six known missense variants in the KIF21A and TUBB3 genes, and a novel variant (c.3906T > A, p.D1302E) in the KIF21A gene were detected. Most patients with CFEOM1 carrying the KIF21A mutation displayed isolated CFEOM, whereas patients with CFEOM3 carrying the TUBB3 mutation had a wide range of clinical manifestations, either CFEOM alone or syndromes. Nystagmus was also present in 12 patients with CFEOM. Furthermore, the MRI findings varied, ranging from attenuation of the extraocular muscles to dysgenesis of the cranial nerves and brain structure.
CONCLUSIONS: The novel variants identified in this study will further expand the spectrum of pathogenic variants in CFEOM-related genes. However, no phenotype-genotype correlations were established because of the diversity of the clinical characteristics of these patients.

Cisplatin (DDP) is commonly used in the treatment of non-small cell lung cancer (NSCLC), including lung adenocarcinoma (LUAD), and the primary cause for its clinical inefficacy is chemoresistance. Here, we aimed to investigate a novel mechanism of chemoresistance in LUAD cells, focusing on the calcium-sensing receptor (CaSR). In this study, high CaSR expression was detected in DDP-resistant LUAD cells, and elevated CaSR expression is strongly correlated with poor prognosis in LUAD patients receiving chemotherapy. LUAD cells with high CaSR expression exhibited decreased sensitivity to cisplatin, and the growth of DDP-resistant LUAD cells was inhibited by cisplatin treatment in combination with CaSR suppression, accompanied by changes in BRCA1 and cyclin B1 protein expression both in vitro and in vivo. Additionally, an interaction between CaSR and KIF11 was identified. Importantly, suppressing KIF11 resulted in decreased protein levels of BRCA1 and cyclin B1, enhancing the sensitivity of DDP-resistant LUAD cells to cisplatin with no obvious decrease in CaSR. Here, our findings established the critical role of CaSR in promoting cisplatin resistance in LUAD cells by modulating cyclin B1 and BRCA1 and identified KIF11 as a mediator, highlighting the potential therapeutic value of targeting CaSR to overcome chemoresistance in LUAD.

Mitotic centromere-associated kinesin (MCAK) motor protein is a typical member of the kinesin-13 family, which can depolymerize microtubules from both plus and minus ends. A critical issue for the MCAK motor is how it performs the depolymerase activity. To address the issue, the pathway of the MCAK motor moving on microtubules and depolymerizing the microtubules is presented here. On the basis of the pathway, the dynamics of both the wild-type and mutant MCAK motors is studied theoretically, which include the full-length MCAK, the full-length MCAK with mutations in the α4-helix of the motor domain, the mutant full-length MCAK with a neutralized neck, the monomeric MCAK and the mutant monomeric MCAK with a neutralized neck. The studies show that a single dimeric MCAK motor can depolymerize microtubules in a processive manner, with either one tubulin or two tubulins being removed per times. The theoretical results are in agreement with the available experimental data. Moreover, predicted results are provided.

Intervertebral disc degeneration (IVDD) is characterized by the senescence and declining vitality of nucleus pulposus cells (NPCs), often driven by mitochondrial dysfunction. This study elucidates that mesenchymal stem cells (MSCs) play a crucial role in attenuating NPC senescence by secreting mitochondria-containing microvesicles (mitoMVs). Moreover, it demonstrates that static magnetic fields (SMF) enhance the secretion of mitoMVs by MSCs. By distinguishing mitoMV generation from exosomes, this study shifts focus to understanding the molecular mechanisms of SMF intervention, emphasizing cargo transport and plasma membrane budding processes, with RNA sequencing indicating the potential involvement of the microtubule-based transport protein Kif5b. The study further confirms the interaction between Rab22a and Kif5b, revealing Rab22a\'s role in sorting mitoMVs into microvesicles (MVs) and potentially mediating subsequent plasma membrane budding. Subsequent construction of a gelatin methacrylate (GelMA) hydrogel delivery system further addresses the challenges of in vivo application and verifies the substantial potential of mitoMVs in delaying IVDD. This research not only sheds light on the molecular intricacies of SMF-enhanced mitoMV secretion but also provides innovative perspectives for future IVDD therapeutic strategies.

UFMylation is a highly conserved ubiquitin-like post-translational modification that catalyzes the covalent linkage of UFM1 to its target proteins. This modification plays a critical role in the maintenance of endoplasmic reticulum proteostasis, DNA damage response, autophagy, and transcriptional regulation. Mutations in UFM1, as well as in its specific E1 enzyme UBA5 and E2 enzyme UFC1, have been genetically linked to microcephaly. Our previous research unveiled the important role of UFMylation in regulating mitosis. However, the underlying mechanisms have remained unclear due to the limited identification of substrates. In this study, we identified Eg5, a motor protein crucial for mitotic spindle assembly and maintenance, as a novel substrate for UFMylation and identified Lys564 as the crucial UFMylation site. UFMylation did not alter its transcriptional level, phosphorylation level, or protein stability, but affected the mono-ubiquitination of Eg5. During mitosis, Eg5 and UFM1 co-localize at the centrosome and spindle apparatus, and defective UFMylation leads to diminished spindle localization of Eg5. Notably, the UFMylation-defective Eg5 mutant (K564R) exhibited shorter spindles, metaphase arrest, spindle checkpoint activation, and a failure of cell division in HeLa cells. Overall, Eg5 UFMylation is essential for proper spindle organization, mitotic progression, and cell proliferation.

The application of adjuvant treatment has significantly enhanced the survival of patients with resectable non-small cell lung cancer (NSCLC) carrying driver gene mutations. However, adjuvant-targeted therapy remains controversial for some NSCLC patients carrying rare gene mutations such as RET, as there is currently a lack of confirmed randomized controlled trials demonstrating efficacy. In this report, we describe the case of a 58-year-old man with stage IIIA NSCLC who underwent complete lobectomy with selective lymph node dissection. Postoperative next-generation sequencing revealed that the patient harbored a rare KIF13A-RET fusion. The patient elected to receive adjuvant treatment with pralsetinib monotherapy and underwent serial circulating tumor DNA (ctDNA) monitoring after surgery. During follow-up, despite experiencing dose reduction and irregular medication adherence, the patient still achieved a satisfactory disease-free survival (DFS) of 27 months. Furthermore, ctDNA predicted tumor recurrence 4 months earlier than imaging techniques. The addition of bevacizumab to the original regimen upon recurrence continued to be beneficial. Pralsetinib demonstrated promising efficacy as adjuvant therapy, while ctDNA analysis offered a valuable tool for early detection of tumor recurrence. By leveraging targeted therapies and innovative monitoring techniques, we aim to improve outcomes and quality of life for NSCLC patients in the future.

Immune therapy has significantly improved the prognosis of hepatocellular carcinoma (HCC) patients, yet its efficacy remains limited, underscoring the urgency to identify new therapeutic targets and biomarkers. Here, we investigated the pathological and physiological roles of KIF20A and assess its potential in enhancing HCC treatment efficacy when combined with PD-1 inhibitors. We initially assess KIF20A\'s oncogenic function using liver-specific KIF20A knockout (Kif20a CKO) mouse models and orthotopic xenografts. Subsequently, we establish a regulatory axis involving KIF20A, FBXW7, and c-Myc, validated through construction of c-Myc splicing mutants. Large-scale clinical immunohistochemistry (IHC) analyses confirm the pathological relevance of the KIF20A-FBXW7-c-Myc axis in HCC. We demonstrate that KIF20A overexpression correlates with poor prognosis in HCC by competitively inhibiting FBXW7-mediated degradation of c-Myc, thereby promoting glycolysis and enhancing tumor proliferation. Conversely, KIF20A downregulation suppresses these effects, impairing tumor growth through c-Myc downregulation. Notably, KIF20A inhibition attenuates c-Myc-induced MMR expression, associated with improved prognosis in HCC patients receiving PD-1 inhibitor therapy. Furthermore, in Kif20a CKO HCC mouse models, we observe synergistic effects between Kif20a knockout and anti-PD-1 antibodies, significantly enhancing immunotherapeutic efficacy against HCC. Our findings suggest that targeting the KIF20A-c-Myc axis could identify HCC patients likely to benefit from anti-PD-1 therapy. In conclusion, we propose that combining KIF20A inhibitors with anti-PD-1 treatment represents a promising therapeutic strategy for HCC, offering new avenues for clinical development and patient stratification.

The dimeric kinesin-8 motors have the biological function of depolymerizing microtubules (MTs) from the plus end. However, the molecular mechanism of the depolymerization promoted by the kinesin-8 motors is still undetermined. Here, a model is proposed for the MT depolymerization by the kinesin-8 motors. Based on the model, the dynamics of depolymerization in the presence of the single motor at the MT plus end under no load and under load on the motor is studied theoretically. The dynamics of depolymerization in the presence of multiple motors at the MT plus end is also analyzed. The theoretical results explain well the available experimental data. The studies can also be applicable to other families of kinesin motors such as kinesin-13 mitotic centromere-associated kinesin motors that have the ability to depolymerize MTs.

Tubulin posttranslational modifications (PTMs) modulate the dynamic properties of microtubules and their interactions with other proteins. However, the effects of tubulin PTMs were often revealed indirectly through the deletion of modifying enzymes or the overexpression of tubulin mutants. In this study, we directly edited the endogenous tubulin loci to install PTM-mimicking or -disabling mutations and studied their effects on microtubule stability, neurite outgrowth, axonal regeneration, cargo transport, and sensory functions in the touch receptor neurons of Caenorhabditis elegans. We found that the status of β-tubulin S172 phosphorylation and K252 acetylation strongly affected microtubule dynamics, neurite growth, and regeneration, whereas α-tubulin K40 acetylation had little influence. Polyglutamylation and detyrosination in the tubulin C-terminal tail had more subtle effects on microtubule stability likely by modulating the interaction with kinesin-13. Overall, our study systematically assessed and compared several tubulin PTMs for their impacts on neuronal differentiation and regeneration and established an in vivo platform to test the function of tubulin PTMs in neurons.

At present, the role of many long non-coding RNAs (lncRNAs) as tumor suppressors in the formation and development of cervical cancer (CC) has been studied. However, lncRNA prostate cancer gene expression marker 1 (PCGEM1), whose high expression not only aggravates ovarian cancer but also can induce tumorigenesis and endometrial cancer progression, has not been studied in CC. The objective of this study was to investigate the expression and the underlying role of PCGEM1 in CC. The relative expression of PCGEM1 in CC cells was detected by real-time PCR. After the suppression of PCGEM1 expression by shRNA, the changes in the proliferation, migration, and invasion capacities were detected via CCK-8 assay, EdU assay, and colony formation assay wound healing assay. Transwell assay and the changes in expressions of epithelial-to-mesenchymal transition (EMT) markers were determined by western blot and immunofluorescence. The interplay among PCGEM1, miR-642a-5p, and kinesin family member 5B (KIF5B) was confirmed by bioinformatics analyses and luciferase reporter assay. Results showed that PCGEM1 expressions were up-regulated within CC cells. Cell viabilities, migration, and invasion were remarkably reduced after the suppression of PCGEM1 expression by shRNA in Hela and SiHa cells. N-cadherin was silenced, but E-cadherin expression was elevated by sh-PCGEM1. Moreover, by sponging miR-642a-5p in CC, PCGEM1 was verified as a competitive endogenous RNA (ceRNA) that modulates KIF5B levels. MiR-642a-5p down-regulation partially rescued sh-PCGEM1\'s inhibitory effects on cell proliferation, migration, invasion, and EMT process. In conclusion, the PCGEM1/miR-642a-5p/KIF5B signaling axis might be a novel therapeutic target in CC. This study provides a research basis and new direction for targeted therapy of CC.