The postsynaptic density protein Abelson interactor protein 1 interacts with the motor protein Kinesin family member 26B in hippocampal neurons

Orchestration of synaptic functions by WAVE regulatory complex-mediated actin reorganization

The WAVE regulatory complex (WRC), composed of five components-Cyfip1/Sra1, WAVE/Scar, Abi, Nap1/Nckap1, and Brk1/HSPC300-is essential for proper actin cytoskeletal dynamics and remodeling in eukaryotic cells, likely by matching various patterned signals to Arp2/3-mediated actin nucleation. Accumulating evidence from recent studies has revealed diverse functions of the WRC in neurons, demonstrating its crucial role in dictating the assembly of molecular complexes for the patterning of various trans-synaptic signals. In this review, we discuss recent exciting findings on the physiological role of the WRC in regulating synaptic properties and highlight the involvement of WRC dysfunction in various brain disorders.

ELK1-induced up-regulation of KIF26B promotes cell cycle progression in breast cancer

KIF26B is a member of the kinesin superfamily that is up-regulated in various tumors, including breast cancer (BC), which can promote tumor progression. This study aimed to investigate the potential function of KIF26B in BC, and the underlying mechanisms, focusing mainly on cell proliferation. KIF26B expression was examined in BC tissue samples obtained from 99 patients. Then, we performed MTS, EdU and flow cytometry assays to detect cell proliferation, and western blotting to measure the expression of cell cycle-related proteins in MDA-MB-231 and MDA-MB-468 cells following KIF26B knockdown. Promoter analysis was used to study the upstream regulatory mechanism of KIF26B. KIF26B was upregulated in BC tissues. High expression of KIF26B was associated with clinicopathological parameters, such as positive lymph node metastasis, higher tumor grade, and higher proliferative index in BC. Furthermore, knockdown of KIF26B expression inhibited MDA-MB-231 and MDA-MB-468 cell proliferation, arresting cells in the G₁ phase of the cell cycle in vitro. Similarly, KIF26B silencing decreased the expression levels of Wnt, β-catenin, and cell cycle-related proteins such as c-Myc, cyclin D1, and cyclin-dependent kinase 4, while increasing the expression of p27. Moreover, ELK1 could bind to the core promoter region of KIF26B and activate its transcription. KIF26B acts as an oncogene in BC by regulating multiple proteins involved in the cell cycle. ELK1 activates KIF26B transcription.

Association of a Novel KIF26B Gene Polymorphism with Susceptibility to Schizophrenia and Breast Cancer: A Case-Control Study

BACKGROUND

KIF26B gene is found to play essential roles in regulating different aspects of cell proliferation and development of the nervous system. We aimed to determine if rs12407427 T/C polymorphism could affect susceptibility to schizophrenia (SZN) and breast cancer (BC), the two genetically correlated diseases.

METHODS

The current case-control study was performed from Aug 2018 to Dec 2018. Briefly, 159 female pathologically confirmed BC cases referring to Alzahra Hospital, Isfahan, Iran, and 102 psychologically confirmed SZN patients (60 males and 42 females) admitted to Baharan Hospital, Zahedan, Iran, were enrolled. Using the salting-out method, genomic DNA was extracted, and variants were genotyped using allele-specific amplification refractory mutation system polymerase chain reaction (ARMS-PCR) method.

RESULTS

The results revealed a significant association between the KIF26B rs12407427 codominant CT (P=0.001), CC (P=0.0001), dominant CT+CC, and recessive CC (P=0.001) genotypes with the risk of developing SZN. Significant correlations were also found regarding rs12407427 and BC susceptibility in different inheritance models, including over-dominant CT (P=0.026), dominant CT+CC (P=0.001), recessive CC (P=0.009), and codominant CT and CC (P=0.001) genotypes. The over-presence of the C allele was also correlated with an increased risk for SZN (P=0.0001) and BC (P=0.0001). Finally, computational analysis predicted that T/C variation in this polymorphism could change the binding sites in proteins involved in splicing.

CONCLUSION

rs12407427 T/C as a de novo KIF26B variant might be a novel genetic biomarker for SZN and/or BC susceptibility in a sample of the Iranian population.

mRNA and miRNA expression profiles in an ectoderm-biased substate of human pluripotent stem cells

The potential applications of human pluripotent stem cells, embryonic stem (ES) cells, and induced pluripotent stem (iPS) cells in cell therapy and regenerative medicine have been widely studied. The precise definition of pluripotent stem cell status during culture using biomarkers is essential for basic research and regenerative medicine. Culture conditions, including extracellular matrices, influence the balance between self-renewal and differentiation. Accordingly, to explore biomarkers for defining and monitoring the pluripotent substates during culture, we established different substates in H9 human ES cells by changing the extracellular matrix from vitronectin to Matrigel. The substate was characterised by low and high expression of the pluripotency marker R-10G epitope and the mesenchymal marker vimentin, respectively. Immunohistochemistry, induction of the three germ layers, and exhaustive expression analysis showed that the substate was ectoderm-biased, tended to differentiate into nerves, but retained the potential to differentiate into the three germ layers. Further integrated analyses of mRNA and miRNA microarrays and qPCR analysis showed that nine genes (COL9A2, DGKI, GBX2, KIF26B, MARCH1, PLXNA4, SLC24A4, TLR4, and ZHX3) were upregulated in the ectoderm-biased cells as ectoderm-biased biomarker candidates in pluripotent stem cells. Our findings provide important insights into ectoderm-biased substates of human pluripotent stem cells in the fields of basic research and regenerative medicine.

miR-450b-5p loss mediated KIF26B activation promoted hepatocellular carcinoma progression by activating PI3K/AKT pathway

BACKGROUND

Kinesin family member 26B (KIF26B) is unveiled acted as important role in many solid tumors, however, the function of KIF26B in hepatocellular carcinoma (HCC) is unclear.

METHODS

The expression of KIF26B in HCC tissues and cell lines were measured with immunochemistry, real-time PCR and western blotting. The correlation between KIF26B expression and clinicopathological characteristics were analyzed by SPSS19.0. Functional experiments of KIF26B was conducted by CCK-8, transwell, EDU, colony formation in vitro and tumorigenesis in vivo. The gene set enrichment analysis was used to search the downstream pathway, luciferase reporter experiment was used to find the upstream regulatory factor of KIF26B.

RESULTS

In this study, we found that KIF26B was overexpressed both in HCC tissues and cell lines. High expression of KIF26B was associated with poor overall survival (OS), late TNM stage and poor differentiation. Loss of function experiments showed that suppression of KIF26B could inhibit cell viability, proliferation rate and invasion ability of HCC cells. KEGG and GO analysis showed that expression of KIF26B was highly relevant with PI3K/AKT signal pathway, and suppression of KIF26B could decrease the expression of m-TOR, p-PI3K and p-AKT. Further study demonstrated that expression of KIF26B was negative correlated with miR-450b-5p level in HCC tissues, and miR-450b-5p could inhibit cell viability, proliferation rate and invasion ability of HCC cells via targeted inhibiting KIF26B.

CONCLUSION

Our study demonstrated that miR-450-5p/KIF26B/AKT axis is critical for progression of HCC, and might provide novel prognostic biomarker and therapeutic target for HCC.

De novo variant in KIF26B is associated with pontocerebellar hypoplasia with infantile spinal muscular atrophy

KIF26B is a member of the kinesin superfamily with evolutionarily conserved functions in controlling aspects of embryogenesis, including the development of the nervous system, though its function is incompletely understood. We describe an infant with progressive microcephaly, pontocerebellar hypoplasia, and arthrogryposis secondary to the involvement of anterior horn cells and ventral (motor) nerves. We performed whole exome sequencing on the trio and identified a de novo KIF26B missense variant, p.Gly546Ser, in the proband. This variant alters a highly conserved amino acid residue that is part of the phosphate-binding loop motif and motor-like domain and is deemed pathogenic by several in silico methods. Functional analysis of the variant protein in cultured cells revealed a reduction in the KIF26B protein's ability to promote cell adhesion, a defect that potentially contributes to its pathogenicity. Overall, KIF26B may play a critical role in the brain development and, when mutated, cause pontocerebellar hypoplasia with arthrogryposis.

Knockdown of KIF26B inhibits breast cancer cell proliferation, migration, and invasion

Background

Kinesin family member 26B (KIF26B) plays a key role in the development and progression of many human cancers. However, the role and underlying mechanisms of KIF26B in breast cancer cells remain unknown.

Materials and methods

In this study, we inhibited the expression of KIF26B in MDA-MB-231 and MCF-7 cells using lentivirus-delivered shRNA.

Results

Lentivirus-mediated KIF26B knockdown significantly suppressed cell proliferation, colony formation, migration, and invasion. Furthermore, cell cycle analyses revealed that the percentage of cells in the G0/G1 phase was significantly increased in KIF26B knockdown cells. Moreover, the knockdown of KIF26B significantly promoted cell apoptosis via the upregulation of cleaved caspase-3 and Bax.

Conclusion

Our data indicate that KIF26B plays a pivotal role in tumor growth and metastasis in breast cancer cells and may be a potential therapeutic target for treating breast cancer.

Kif26b controls endothelial cell polarity through the Dishevelled/Daam1-dependent planar cell polarity-signaling pathway

Angiogenesis involves the coordinated growth and migration of endothelial cells (ECs) toward a proangiogenic signal. The Wnt planar cell polarity (PCP) pathway, through the recruitment of Dishevelled (Dvl) and Dvl-associated activator of morphogenesis (Daam1), has been proposed to regulate cell actin cytoskeleton and microtubule (MT) reorganization for oriented cell migration. Here we report that Kif26b--a kinesin--and Daam1 cooperatively regulate initiation of EC sprouting and directional migration via MT reorganization. First, we find that Kif26b is recruited within the Dvl3/Daam1 complex. Using a three-dimensional in vitro angiogenesis assay, we show that Kif26b and Daam1 depletion impairs tip cell polarization and destabilizes extended vascular processes. Kif26b depletion specifically alters EC directional migration and mislocalized MT organizing center (MTOC)/Golgi and myosin IIB cell rear enrichment. Therefore the cell fails to establish a proper front-rear polarity. Of interest, Kif26b ectopic expression rescues the siDaam1 polarization defect phenotype. Finally, we show that Kif26b functions in MT stabilization, which is indispensable for asymmetrical cell structure reorganization. These data demonstrate that Kif26b, together with Dvl3/Daam1, initiates cell polarity through the control of PCP signaling pathway-dependent activation.

Placental DNA Methylation Related to Both Infant Toenail Mercury and Adverse Neurobehavioral Outcomes

BACKGROUND

Prenatal mercury (Hg) exposure is associated with adverse child neurobehavioral outcomes. Because Hg can interfere with placental functioning and cross the placenta to target the fetal brain, prenatal Hg exposure can inhibit fetal growth and development directly and indirectly.

OBJECTIVES

We examined potential associations between prenatal Hg exposure assessed through infant toenail Hg, placental DNA methylation changes, and newborn neurobehavioral outcomes.

METHODS

The methylation status of > 485,000 CpG loci was interrogated in 192 placental samples using Illumina's Infinium HumanMethylation450 BeadArray. Hg concentrations were analyzed in toenail clippings from a subset of 41 infants; neurobehavior was assessed using the NICU Network Neurobehavioral Scales (NNNS) in an independent subset of 151 infants.

RESULTS

We identified 339 loci with an average methylation difference > 0.125 between any two toenail Hg tertiles. Variation among these loci was subsequently found to be associated with a high-risk neurodevelopmental profile (omnibus p-value = 0.007) characterized by the NNNS. Ten loci had p < 0.01 for the association between methylation and the high-risk NNNS profile. Six of 10 loci reside in the EMID2 gene and were hypomethylated in the 16 high-risk profile infants' placentas. Methylation at these loci was moderately correlated (correlation coefficients range, -0.33 to -0.45) with EMID2 expression.

CONCLUSIONS

EMID2 hypomethylation may represent a novel mechanism linking in utero Hg exposure and adverse infant neurobehavioral outcomes.

Elevated kinesin family member 26B is a prognostic biomarker and a potential therapeutic target for colorectal cancer

Background

Kinesins play a key role in the development and progression of many human cancers. The present study investigated the expression and clinical significance of kinesin family member 26B (KIF26B) in colorectal cancer (CRC).

Methods

Using quantitative real-time PCR and Western blot analyses as well as immunohistochemical staining of a tissue microarray we examined KIF26B mRNA and protein levels in CRC tumor tissues and paired adjacent normal mucosa. Moreover, the effect of KIF26B knockdown on CRC cell proliferation was investigated using Cell Counting Kit-8 assays.

Results

Expression of KIF26B was found to be elevated in CRC. Suppression of KIF26B inhibited CRC cell proliferation. Furthermore, upregulated expression of KIF26B was significantly correlated with tumor size (P = 0.020), American Joint Committee on Cancer (AJCC) stage (P = 0.018), T stage (P = 0.026), N stage (P = 0.013), and differentiation histology (P = 0.047). KIF26B was also shown to be an independent prognostic indicator of overall survival for CRC patients (HR 5.621; 95% CI 2.302–13.730; P < 0.001).

Conclusion

Our data indicate that KIF26B plays an important role in colorectal carcinogenesis and functions as a novel prognostic indicator and a potential therapeutic target for CRC.