Overexpression of chromokinesin KIF4 inhibits proliferation of human gastric carcinoma cells both in vitro and in vivo

ERCC6L facilitates the onset of mammary neoplasia and promotes the high malignance of breast cancer by accelerating the cell cycle

BACKGROUND

Breast cancer (BC) is the leading cause of morbidity and the second leading cause of death among female malignant tumors. Although available drugs have been approved for the corresponding breast cancer subtypes (ER-positive, HER2+) currently, there are still no effective targeted drugs or treatment strategies for metastatic breast cancer or triple-negative breast cancer that lack targets. Therefore, it is urgent to discover new potential targets. ERCC6L is an essential protein involved in chromosome separation during cell mitosis. However, the effect of ERCC6L on the tumorigenesis and progression of breast cancer is unclear.

METHODS AND RESULTS

Here, we found that ERCC6L was highly expressed in breast cancer, especially in TNBC, which was closely related to poor outcomes of patients. An ERCC6L conditional knockout mouse model was first established in this study, and the results confirmed that ERCC6L was required for the development of the mammary gland and the tumorigenesis and progression of mammary gland cancers. In in vitro cell culture, ERCC6L acted as a tumor promoter in the malignant progression of breast cancer cells. Overexpression of ERCC6L promoted cell proliferation, migration and invasion, while knockdown of ERCC6L caused the opposite results. Mechanistically, ERCC6L accelerated the cell cycle by regulating the G2/M checkpoint signalling pathway. Additionally, we demonstrated that there is an interaction between ERCC6L and KIF4A, both of which are closely related factors in mitosis and are involved in the malignant progression of breast cancer.

CONCLUSIONS

We first demonstrated that ERCC6L deficiency can significantly inhibit the occurrence and development of mammary gland tumors. ERCC6L was found to accelerate the cell cycle by regulating the p53/p21/CDK1/Cyclin B and PLK/CDC25C/CDK1/Cyclin B signalling pathways, thereby promoting the malignant progression of breast cancer cell lines. There was a direct interaction between KIF4A and ERCC6L, and both are closely associated with mitosis and contribute to growth and metastasis of breast tumor. To sum up, our results suggest that ERCC6L may be used as a promising target for the treatment of BC.

Bioinformatic and Experimental Analyses Reveal That KIF4A Is a Biomarker of Therapeutic Sensitivity and Predicts Prognosis in Cervical Cancer Patients

OBJECTIVE

This study aims to investigate the expression, prognostic value, and function of kinesin superfamily 4A (KIF4A) in cervical cancer.

METHODS

Cervical cancer cell lines (Hela and SiHa) and TCGA data were used for experimental and bioinformatic analyses. Overall survival (OS) and progression free survival (PFS) were compared between patients with high or low KIF4A expression. Copy number variation (CNV) and somatic mutations of patients were visualized and GISTIC 2.0 was used to identify significantly altered sites. The function of KIF4A was also explored based on transcriptome analysis and validated by experimental methods. Chemotherapeutic and immunotherapeutic benefits were inferred using multiple reference databases and algorithms.

RESULTS

Patients with high KIF4A expression had better OS and PFS. KIF4A could inhibit proliferation and migration and induce G₁ arrest of cervical cancer cells. Higher CNV load was observed in patients with low KIF4A expression, while the group with low KIF4A expression displayed more significantly altered sites. A total of 13 genes were found to mutate more in the low KIF4A expression group, including NOTCH1 and PUM1. The analysis revealed that low KIF4A expression may indicate an immune escape phenotype, and patients in this group may benefit more from immunotherapy. With respect to chemotherapy, cisplatin and gemcitabine may respond better in patients with high KIF4A expression, while 5-fluorouracil etc. may be responded better in patients with low KIF4A expression CONCLUSION: KIF4A is a tumor suppressor gene in cervical cancer, and it can be used as a prognostic and therapeutic biomarker in cervical cancer.

Role of motor proteins in human cancers

Motor proteins include several protein families (Kinesin, Dynein and Myosin) responsible for intracellular transport, intercellular communication, among other functions. In cancer cells, motor proteins along with microtubules (MT) and other tubulin and actin structures, are crucial for cell proliferation and invasion. The cBioPortal platform for Cancer Genomics database was queried for solid cancers in a combined cohort of 9204 patients with complete cancer genomics data. To assess the importance of motor proteins in cancer, copy number alterations (CNAs) and survival rates were analyzed in the combined dataset. Kinesin, Dynein, and Myosin families showed CNAs in 47%, 49%, and 57 % of patients, respectively, in at least one of their members. Survival analysis showed that CNAs in Kinesin and Dynein, families' genes in the same patients were significantly correlated to decreased overall survival. These results added more evidence to previous literature highlighting the importance of motor proteins as a target in cancer therapy. Kinesin inhibitors could act by several mechanisms such as inhibiting spindle assembly or centrosome separation during mitosis, leading to cell cycle arrest and eventually apoptosis. Dynein inhibitors modulate Dynein's activity and MT binding, inhibiting cell proliferation and invasion. Myosin inhibitors act by stabilizing MT, inducing cell cycle arrest and inhibiting invasiveness. Increasing the specificity of motor proteins targeting drugs could improve cancer therapy and patient survival.

Evaluating the Expression and Prognostic Value of Genes Encoding Microtubule-Associated Proteins in Lung Cancer

Microtubule-associated proteins (MAPs) play essential roles in cancer development. This study aimed to identify transcriptomic biomarkers among MAP genes for the diagnosis and prognosis of lung cancer by analyzing differential gene expressions and correlations with tumor progression. Gene expression data of patients with lung adenocarcinoma (LUAD) and lung squamous cell carcinoma (LUSC) from the Cancer Genome Atlas (TCGA) database were used to identify differentially expressed MAP genes (DEMGs). Their prognostic value was evaluated by Kaplan-Meier and Cox regression analysis. Moreover, the relationships between alterations in lung cancer hallmark genes and the expression levels of DEMGs were investigated. The candidate biomarker genes were validated using three independent datasets from the Gene Expression Omnibus (GEO) database and by quantitative reverse transcription polymerase chain reaction (qRT-PCR) on clinical samples. A total of 88 DEMGs were identified from TCGA data. The 20 that showed the highest differential expression were subjected to association analysis with hallmark genes. Genetic alterations in TP53, EGFR, PTEN, NTRK1, and PIK3CA correlated with the expression of most of these DEMGs. Of these, six candidates-NUF2, KIF4A, KIF18B, DLGAP5, NEK2, and LRRK2-were significantly differentially expressed and correlated with the overall survival (OS) of the patients. The mRNA expression profiles of these candidates were consistently verified using three GEO datasets and qRT-PCR on patient lung tissues. The expression levels of NUF2, KIF4A, KIF18B, DLGAP5, NEK2, and LRRK2 can serve as diagnostic biomarkers for LUAD and LUSC. Moreover, the first five can serve as prognostic biomarkers for LUAD, while LRRK2 can be a prognostic biomarker for LUSC. Our research describes the novel role and potential application of MAP-encoding genes in clinical practice.

KIF11 Is a Promising Therapeutic Target for Thyroid Cancer Treatment

Objective. To assess KIF11 expression in human thyroid tumor tissues and further evaluate its involvement in thyroid cancer. Methods. The expression of KIF11 in 71 cases of thyroid carcinoma as well as corresponding tissues was detected by the immunohistochemical (IHC) method. Patients were divided into the high KIF11 expression as well as low expression groups based on the staining levels. In addition, to study the relationship between the expression of KIF11 as well as clinicopathological features, the effects of KIF11 were detected on the proliferation, apoptosis, and cell cycle of two types of thyroid cancer cells, TPC-1 and KTC-1, through colony formation assays, MTT assays, and FCM assays, respectively. We further assessed the potential effects of KIF11 on tumor growth using an animal model. Results. The significantly high expression of KIF11 in thyroid tumor tissues was revealed, and the correlations between KIF11 expression levels as well as clinical pathological features (T stage and intraglandular dissemination) of patients were revealed. We further noticed that KIF11 knockdown remarkably suppressed thyroid cancer cell proliferation as well as induced cell apoptosis of thyroid cancer cells. Additionally, KIF11 contributed to tumor growth of thyroid cancer cells in mice. Conclusions. We noticed the involvement of KIF11 in the progression of thyroid cancer.

Kif4A mediates resistance to neoadjuvant chemoradiotherapy in patients with advanced colorectal cancer via regulating DNA damage response

More and more patients with advanced colorectal cancer (CRC) have benefited from surgical resection or ablation following neoadjuvant chemoradiotherapy (nCRT), but nCRT may be ineffective and have potential risks to some patients. Therefore, it is necessary to discover effective biomarkers for predicting the nCRT efficacy in CRC patients. Chromokinesin Kif4A plays a critical role in mitosis, DNA damage repair and tumorigenesis, but its relationship with nCRT efficacy in advanced CRC remains unclear. Here, we find that Kif4A expression in pretreated tumor tissue is positively correlated with poorer tumor regression after receiving nCRT ( P=0.005). Knockdown of endogenous Kif4A causes an increased sensitivity of CRC cells to chemotherapeutic drugs 5-fluorouracil (5-FU) and Cisplatin (DDP), while overexpression of Kif4A enhances resistance of CRC cells to the chemotherapeutic drugs. Furthermore, depending on its motor domain and tail domain, Kif4A regulates DNA damage response (DDR) induced by 5-FU or DDP treatment in CRC cells. In conclusion, we demonstrate that Kif4A may be a potential independent biomarker for predicting the nCRT efficacy in advanced CRC patients, and Kif4A regulates chemosensitivity of CRC cells through controlling DDR.

KIF4A Regulates the Progression of Pancreatic Ductal Adenocarcinoma through Proliferation and Invasion

Background

Pancreatic cancer is a malignant tumor of the digestive tract, which is difficult to diagnose and treat due to bad early diagnosis. We aimed to explore the role of kinesin superfamily 4A (KIF4A) in pancreatic ductal adenocarcinoma (PDAC).

Methods

We first used the bioinformatic website to screen the data of pancreatic cancer in TCGA, and KIF4A protein was detected among the 86 specimens of patients in our hospital combined with clinic-pathological characteristics and survival analysis. KIF4A loss-expression cell lines were established by RNA interference (RNAi). In addition, we performed in vitro cell assays to detect the changes in cell proliferation, migration, and invasion. The proteins involved in the proliferation and metastasis of cancer cells were also detected by western blot. The above results could be proved in vivo. Further, the correlation between KIF4A and CDC5L was analyzed by TCGA and IHC data.

Results

We first found a high expression of KIF4A in pancreatic cancer, suggesting a role of KIF4A in the development of pancreatic cancer. KIF4A was found to be differentially expressed (P < 0.05) among the 86 specimens of patients in our hospital and was significantly associated with PDAC TNM stages and tumor size. High KIF4A expression also significantly worsened overall survival (OS) and disease-free survival rate (DFS) (P < 0.05, respectively). In addition, cell proliferation, migration, and invasion were inhibited by the KIF4A-shRNA group compared with the control (P < 0.05, respectively). In the end, knockdown of KIF4A could inhibit tumor development and metastasis in vivo. Further, the positive correlation between KIF4A and CDC5L existed, and KIF4A might promote pancreatic cancer proliferation by affecting CDC5L expression.

Conclusion

In conclusion, the high expression level of KIF4A in PDAC was closely related to poor clinical and pathological status, lymphatic metastasis, and vascular invasion. KIF4A might be involved in promoting the development of PDAC in vitro and in vivo, which might be a new therapeutic target of PDAC.

Identification of KIF4A as a prognostic biomarker for esophageal squamous cell carcinoma

Esophageal squamous cell carcinoma (ESCC) is the most common and aggressive tumor worldwide, and the long-term survival of these patients remains poor. Three databases (GSE17351, GSE20347, and GSE100942) were obtained from Gene Expression Omnibus, and 193 differentially expressed genes including 56 upregulated and 137 downregulated genes were identified by paired test using limma R package. Then, functional enrichments by gene ontology and Kyoto Encyclopedia of Genes and Genomes analyses showed these genes were mainly related protein digestion and absorption, and IL-17 signaling pathway. We then constructed a protein-protein interaction network and cytoHubba module to determine the six hub genes and overall survival analysis of the six hub genes were evaluated by UALCAN and GEPIA2 analysis. Ultimately, the experimental results confirmed the KIF4A was overexpressed in the ESCC tissues and cell lines compared with the normal esophageal mucosal tissues and was linked to poor prognosis. Moreover, we also revealed that KIF4A facilitates proliferation, cell cycle, migration, and invasion of ESCC in vivo and in vitro. Overall, these findings demonstrated that KIF4A could serve as diagnostic and prognostic biomarkers and may help facilitate therapeutic targets in ESCC patients.

Enhanced expression of KIF4A in osteosarcoma predicts a poor prognosis and facilitates tumor growth by activation of the MAPK pathway

The present study aimed to explore the prognostic value and role of kinesin family member 4A (KIF4A) expression in human osteosarcoma. KIF4A expression was evaluated in human osteosarcoma tissues from The Cancer Genome Atlas and Gene Expression Omnibus datasets. Reverse transcription-quantitative PCR was then applied to assess KIF4A level in both osteosarcoma cell lines and tissues. The association between KIF4A expression and clinical results in patients with osteosarcoma was detected by survival analysis. MTT assays and colony formation assays were used to evaluate the effects of KIF4A on osteosarcoma cell proliferation. The results indicated that the level of KIF4A was increased and associated with a poor prognosis in osteosarcoma tissues. Knockdown of KIF4A was shown to inhibit osteosarcoma cellular proliferation by affecting the MAPK pathway. The level of KIF4A was high in the human osteosarcoma tissues and this could be considered as a tumor induction gene, which may be used as an indicator of prognosis.

Identification and analysis of genes associated with epithelial ovarian cancer by integrated bioinformatics methods

Background

Though considerable efforts have been made to improve the treatment of epithelial ovarian cancer (EOC), the prognosis of patients has remained poor. Identifying differentially expressed genes (DEGs) involved in EOC progression and exploiting them as novel biomarkers or therapeutic targets is of great value.

Methods

Overlapping DEGs were screened out from three independent gene expression omnibus (GEO) datasets and were subjected to Gene ontology (GO) and Kyoto encyclopedia of genes and genomes (KEGG) pathway enrichment analyses. The protein-protein interactions (PPI) network of DEGs was constructed based on the STRING database. The expression of hub genes was validated in GEPIA and GEO. The relationship of hub genes expression with tumor stage and overall survival and progression-free survival of EOC patients was investigated using the cancer genome atlas data.

Results

A total of 306 DEGs were identified, including 265 up-regulated and 41 down-regulated. Through PPI network analysis, the top 20 genes were screened out, among which 4 hub genes, which were not researched in depth so far, were selected after literature retrieval, including CDC45, CDCA5, KIF4A, ESPL1. The four genes were up-regulated in EOC tissues compared with normal tissues, but their expression decreased gradually with the continuous progression of EOC. Survival curves illustrated that patients with a lower level of CDCA5 and ESPL1 had better overall survival and progression-free survival statistically.

Conclusion

Two hub genes, CDCA5 and ESPL1, identified as probably playing tumor-promotive roles, have great potential to be utilized as novel therapeutic targets for EOC treatment.

KIF4A promotes the development of bladder cancer by transcriptionally activating the expression of CDCA3

Bladder cancer (BC) is among the most common urinary system tumors with a high morbidity and mortality worldwide. Despite advancements being made in the diagnosis and treatment of bladder cancer, targeted therapy remains the most promising treatment, and novel therapeutic targets are urgently required in to improve the outcomes of patients with BC. Kinesin family member 4A (KIF4A) is a plus-end directed motor protein involved in the regulation of multiple cellular processes, such as mitosis and axon growth. Notably, KIF4A plays important roles in tumor growth and progression, and its expression is associated with the prognosis of several types of cancer. However, the potential role and molecular mechanisms of KIF4A in bladder cancer development remain unclear. The present study demonstrated that KIF4A was highly expressed in human BC tissues, and its expression was associated with patient clinicopathological characteristics, such as tumor stage (P=0.012) and with the prognosis of patients with BC. It was further found that KIF4A promoted the cell proliferation of bladder cancer both in vitro and in vivo. On the whole, the data presented herein provide evidence that KIF4A promotes the development of BC through the transcriptional activation of the expression of CDCA3. The present study indicates the involvement of KIF4A in the progression of BC and suggests that KIF4A may be a promising therapeutic target for the treatment of BC.

Effect of KIF22 on promoting proliferation and migration of gastric cancer cells via MAPK-ERK pathways

Background

Gastric cancer (GC) is one of the most globally prevalent cancers in the world. The pathogenesis of GC has not been fully elucidated, and there still lacks effective targeted therapeutics. The influence of altered kinesin superfamily protein 22 (KIF22) expression in GC progression is still unclearly. The aim of this study was to investigate the KIF22 effects on GC and related mechanisms.

Methods

Gastric carcinoma tissues and matching non-cancerous tissues were collected from patients with GC who have accepted a radical gastrectomy in Lanzhou University Second Hospital from May 2013 to December 2014. The expression of KIF22 was examined in GC of 67 patients and 20 para-carcinoma tissues by immunochemical staining. The relationship between the expression of KIF22 and clinicopathologic characteristics was next investigated in the remaining 52 patients except for 15 patients who did not complete follow-up for 5 years. Cell viability was performed via 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) test and colony formation assay in the MGC-803 and BGC-823 GC cells. Cell scratch and trans-well invasion assay was performed to assess migration ability in the MGC-803 and BGC-823 GC cells. Gene set enrichment analysis (GSEA) pathway enrichment analysis was performed to explore the potential functions. Cell cycle was detected by flow cytometry. In addition, the two GC cell lines were used to elucidate the underlying mechanism of KIF22 in GC in vitro via assessing the effects on mitogen-activated protein kinase and extracellular regulated protein kinases (MAPK/ERK) signal transduction pathway-related expressions by Western blotting assays. The differences were compared by t tests, one-way analysis of variance, and Chi-squared tests.

Results

The study showed that KIF22 was up-regulated in GC, and KIF22 high expression was significantly related to differentiation degree (χ² = 12.842, P = 0.002) and poorly overall survivals. GSEA pathway enrichment analysis showed that KIF22 was correlated with the cell cycle. Silence of KIF22 decreased the ability of the proliferation and migration in gastric cells, induced G1/S phase cell cycle arrest via regulating the MAPK-ERK pathways.

Conclusions

KIF22 protein level was negatively correlated with prognosis. KIF22 knockdown might inhibit proliferation and metastasis of GC cells via the MAPK-ERK signaling pathway.

Identification of potential prognostic biomarkers for breast cancer using WGCNA and PPI integrated techniques

In this study, we aimed to detect promising prognostic factors of breast cancer and interpreted the relevant mechanisms using an integrated bioinformatics analysis. RNA sequencing profile of breast cancer was downloaded from The Cancer Genome Atlas (TCGA) and the Genotype-Tissue Expression (GTEx) databases, which were combined as a group (TCGA_GTEx). GSE70947 dataset was from Gene Expression Omnibus. Blue and turquoise modules, respectively identified in TCGA_GTEx database and GSE70947 dataset using weighted co-expression network analysis (WGCNA), were both notably associated with breast cancer. By comparing genes in the two significant modules with differentially expressed genes (DEGs), we obtained a set of 40 shared genes, which were mainly enriched in chromosome segregation and mismatch repair pathway. After protein-protein interaction (PPI) network and overall survival analysis, two hub genes EXO1 and KIF4A were extracted from the set of 40 shared genes, which were up-regulated and associated with the dismal outcome of breast cancer patients. There was a notable negative correlation between EXO1 and KIF4A expression and age of breast cancer patients, whereas a positive relationship with two another clinical traits stage and tumor category was detected. Univariate and multivariate Cox regression analysis revealed that the two hub genes could be independent prognostic factors of breast cancer. Mechanistically, gene correlation analysis suggested that EXO1 and KIF4A exerted their oncogenic role via promoting breast cancer cell proliferation. Overall, our findings identify two promising individual prognostic predictors of breast cancer and pave the new way for diagnosis and therapy strategy of breast cancer.

miR-29c-3p regulates proliferation and migration in ovarian cancer by targeting KIF4A

Background

Increasing evidence suggested that microRNA and kinesin superfamily proteins play an essential role in ovarian cancer. The association between KIF4A and ovarian cancer (OC) was investigated in this study.

Methods

We performed bioinformatics analysis in the GEO database to screen out the differentially expressed miRNAs (DEmiRNAs) associated with ovarian cancer prognosis. Upstream targeting prediction for KIF4A was acquired by using the mirDIP database. The potential regulatory factor miR-29c-3p for KIF4A was obtained from the intersection of the above all miRNAs. The prognosis of KIF4A and target-miRNA in OC was obtained in the subsequent analysis. qRT-PCR and Western blot detected KIF4A expression level in IOSE80 (human normal ovarian epithelial cell line). In the meantime, the gene expression level was detected in A2780, HO-8910PM, COC1, and SKOV3 cell lines (human ovarian carcinoma cell line). MTT and colony formation assays were used to detect cell proliferation of SKOV3 cell line. The following assays detected cell migration through the use of transwell and wound heal assays. Targeted binding relationship between KIF4A and miRNA was detected by using the dual-luciferase reporter assay.

Results

Both high expression of KIF4A and lower expression of miR-29c-3p could be used as biomarkers indicating poor prognosis in OC patients. Cellular function tests confirmed that when KIF4A was silenced, it inhibited the proliferation and migration of OC cells. In addition, 3′-UTR of KIF4A had a direct binding site with miR-29c-3p, which indicated that the expression of KIF4A could be regulated by miR-29c-3p. In subsequent assays, the proliferation and migration of OC cells were inhibited by the overexpression of miR-29c-3p. At the same time, rescue experiments also confirmed that the promotion of KIF4A could be reversed by miR-29c-3p.

Conclusion

In a word, our data revealed a new mechanism for the role of KIF4A in the occurrence and development of OC.

The kinesin motor protein KIF4A as a potential therapeutic target in renal cell carcinoma

Kinesin family member 4A (KIF4A) is located in the human chromosome band Xq13.1. It has a highly conserved kinesin motor region at its N-terminus, which is followed by a central coiled-coil region and a C-terminus cargo-binding domain that contains a cysteine-rich motif. It is aberrantly expressed in a variety of cancers. Our study aimed to determine the expression of KIF4A in renal cell carcinoma (RCC) and to gain new insights into the underlying molecular mechanisms of this disease. Here, we found that KIF4A expression in RCC specimens increased relative to that in normal renal tissues. A significant correlation existed between the expression of KIF4A and the clinicopathologic features of RCC. Elevated KIF4A expression was associated with poor overall survival and disease-free survival. Univariate and multivariate Cox regression analysis revealed that KIF4A was an independent prognostic factor for poor survival in human patients with RCC. CCK-8 proliferation assay, cell cycle analysis, and subcutaneous tumor formation analysis in nude mice consistently showed that KIF4A promoted RCC proliferation. Our findings also indicated that KIF4A functions as an accelerator of RCC metastasis as certified through transwell chamber analysis, wound healing assay, and angiogenesis assay. The expression levels of cyclin D1, cyclin E2, matrix metalloproteinase-2, matrix metalloproteinase-9, hypoxia-inducible factor 1α, and vascular endothelial growth factor in the KIF4A knockdown group were lower than those in the control group and were consistent with those in classic oncogenic pathways. These findings implied that the expression of KIF4A was significantly related to the tumor incidence, metastasis, and prognosis of patients with RCC. Our work provides new breakthroughs for the diagnosis and treatment of RCC.

KIF4A Promotes Clear Cell Renal Cell Carcinoma (ccRCC) Proliferation in vitro and in vivo

PURPOSE

To evaluate the expression in human clear cell renal cell carcinoma (ccRCC) tissues and explore the effects of kinesin family member 4A (KIF4A) on ccRCC progression.

METHODS

GEPIA was used to evaluate the mRNA levels of KIF4A in human ccRCC tissues from TCGA database, and Immunohistochemistry (IHC) assays were performed to assess its expression in human ccRCC tissues collected in our hospital. The clinical-pathological analysis was performed to explore the correlation with KIF4A expression. The effects of KIF4A on ccRCC cell proliferation were detected through colony formation and MTT assays. Finally, the effects of KIF4A on tumor growth were measured using a mice model.

RESULTS

Bioinformation results showed the expression of KIF4A mRNA was upregulated in ccRCC tissues and high expression of KIF4A was related with poor prognosis in ccRCC patients. We also found a high expression of KIF4A in human ccRCC tissues collected in our hospital. We also found its expression level was correlated with clinical characteristics, including T stage (P=0.035*) and lymphatic metastasis (P=0.028*). We further confirmed that knockdown of KIF4A suppressed cell proliferation in HTB-47 and CRL-1932 cells. Furthermore, KIF4A contributes to tumor growth of ccRCC cells in mice.

CONCLUSION

We found the abnormal high expression of KIF4A in human ccRCC tissues and demonstrated that KIF4A could serve as a tumor induction gene.

High kinesin family member 18A expression correlates with poor prognosis in primary lung adenocarcinoma

Background

Lung adenocarcinoma (LUAD) is the most prevalent pathological subtype of lung cancer. Kinesin family member 18A (KIF18A) plays an important role in tumorigenesis. Its roles in breast cancer, colorectal cancer, and other tumors have been demonstrated; however, studies of KIF18A in LUAD are limited. This study aimed to determine the role of KIF18A in LUAD progression and prognostic prediction.

Methods

KIF18A expression was examined in LUAD cells and tissues by immunohistochemistry and Western blotting. Cell proliferation assay was performed to study the role of KIF18A in LUAD cells. Correlations between KIF18A expression and clinicopathological features were analyzed. The role of KIF18A in LUAD prognosis was evaluated using data from The Cancer Genome Atlas (TCGA).

Results

KIF18A expression was increased in tumor cells and tissues. Downregulation of KIF18A expression resulted in the suppression of cancer cell proliferation in in vitro assays, and was particularly related to poor tumor differentiation, big tumor size, lymph node metastasis, and more advanced tumor stage. In the TCGA dataset, high KIF18A messenger RNA expression was associated with poor disease‐free and overall survival in patients with LUAD. In addition, multivariate analysis indicated that KIF18A is an independent prognostic factor of disease‐free and overall survival in LUAD.

Conclusions

Collectively, our results demonstrate that KIFl8A is highly expressed in LUAD. KIFl8A plays an important role in LUAD cell proliferation, but is a poor prognostic factor.

Integrative analysis of KIF4A, 9, 18A, and 23 and their clinical significance in low-grade glioma and glioblastoma

To determine the prognostic significance of kinesin superfamily gene (KIF) expression in patients with brain cancer, including low-grade glioma (LGG) and glioblastoma (GBM), we comprehensively analyzed KIFs in 515 LGG and 595 GBM patients. Among KIFs, KIF4A, 9, 18A, and 23 showed significant clinical implications in both LGG and GBM. The mRNA and protein expression levels of KIF4A, 9, 18A, and 23 were significantly increased in LGG and GBM compared with those in the normal control groups. The mRNA expression levels of KIF4A, 9, 18A, and 23 in LGG were significantly increased in the high-histologic-grade group compared with those with a low histologic grade. Genomic analysis showed that the percent of mRNA upregulation of KIF4A, 9, 18A, and 23 was higher than that of other gene alterations, including gene amplification, deep deletion, and missense mutation. In addition, LGG patients with KIF4A, 18A, and 23 gene alterations were significantly associated with a poor prognosis. In survival analysis, the group with high expression of KIF4A, 9, 18A, and 23 mRNA was significantly associated with a poor prognosis in both LGG and GBM patients. Gene Set Enrichment Analysis (GSEA) revealed that high mRNA expression of KIF4A, 18A, and 23 in LGG and GBM patients showed significant positive correlations with the cell cycle, E2F targets, G₂M checkpoint, Myc target, and mitotic spindle. By contrast, high mRNA expression of KIF9 in both LGG and GBM patients was significantly negatively correlated with the cell cycle, G₂M checkpoint, and mitotic spindle pathway. However, it was significantly positively correlated with EMT and angiogenesis. This study has extended our knowledge of KIF4A, 9, 18A, and 23 in LGG and GBM and shed light on their clinical relevance, which should help to improve the treatment and prognosis of LGG and GBM.

Role of kinesin superfamily in gastrointestinal cancer

Kinesins constitute a protein superfamily that belongs to motor proteins. Kinesins move along microtubules to exert their functions. They play a crucial role in intracellular transportation, mitosis, cell formation, and cell function. Kinesin are not only responsible for the transport of various membrane organelles, protein complexes, mRNA and so on to ensure the basic activity of cells, but also can regulate intracellular molecular signal pathways. Numerous studies have shown that kinesins are closely associated with the development of a variety of human diseases, especially the formation and development of gastrointestinal tumors. This article reviews the role of kinesins in gastrointestinal cancer.

An integrated bioinformatical analysis to evaluate the role of KIF4A as a prognostic biomarker for breast cancer

Purpose

The aim of this study was to investigate the diagnostic and prognostic value of human kinesin family member 4A (KIF4A) as an effective biomarker for breast cancer.

Materials and methods

Cancer Genome Atlas data and 12 independent public breast cancer microarray data sets were downloaded and analyzed using individual and pooled approaches.

Results

The results of our study revealed a strong and positive correlation between KIF4A expression and malignant features of breast cancer. KIF4A had a strong prognostic value in both ER-positive and ER-negative breast cancers comparable to or even better than tumor size, lymph node invasion, and Elston grade. We also found that KIF4A might be the target gene of microRNA-335, which can suppress KIF4A expression by targeting the 3′-untranslated region of its mRNA.

Conclusion

KIF4A might serve as a robust prognostic predictor for breast cancer. Targeting KIF4A activity could be a promising therapeutic option in breast cancer treatment.

KIF4A facilitates cell proliferation via induction of p21-mediated cell cycle progression and promotes metastasis in colorectal cancer

Kinesin family member 4A (KIF4A) was found to be implicated in the regulation of chromosome condensation and segregation during mitotic cell division, which is essential for eukaryotic cell proliferation. However, little is known about the role of KIF4A in colorectal carcinoma (CRC). This study explored the biological function of KIF4A in CRC progression and investigated the potential molecular mechanisms involved. Here, we found that KIF4A was remarkably upregulated in primary CRC tissues and cell lines compared with paired non-cancerous tissues and normal colorectal epithelium. Elevated expression of KIF4A in CRC tissues was significantly correlated with clinicopathological characteristics in patients as well as with shorter overall and disease-free cumulative survival. Multivariate Cox regression analysis revealed that KIF4A was an independent prognostic factor for poor survival in human CRC patients. Functional assays, including a CCK-8 cell proliferation assay, colony formation analysis, cancer xenografts in nude mice, cell cycle and apoptosis analysis, indicated that KIF4A obviously enhanced cell proliferation by promoting cell cycle progression in vitro and in vivo. Furthermore, gene set enrichment analysis, Luciferase reporter assays, and ChIP assays revealed that KIF4A facilitates cell proliferation via regulating the p21 promoter, whereas KIF4A had no effect on cell apoptosis. In addition, Transwell analysis indicated that KIF4A promotes migration and invasion in CRC. Taken together, these findings not only demonstrate that KIF4A contributes to CRC proliferation via modulation of p21-mediated cell cycle progression but also suggest the potential value of KIF4A as a clinical prognostic marker and target for molecular treatments.

Increased KIF4A expression is a potential prognostic factor in prostate cancer

The kinesin super-family protein (KIF) 4A gene is reported to be overexpressed and associated with poor clinical prognosis in human cancers; however, its clinical significance in prostate cancer (PCa) has not been well studied. The present study performed dataset analyses and revealed that KIF4A expression was significantly increased in castration-resistant PCa patients. Additionally, KIF4A expression was significantly highly expressed in PCa tissues compared with non-cancerous tissues, particularly in advanced PCa pathological stages. Upregulated KIF4A mRNA expression in PCa tissues was significantly correlated with shorter overall survival and prostate-specific antigen failure. Furthermore, both univariate and multivariate analyses revealed that upregulated KIF4A may predict poor biochemical recurrence (BCR)-free survival. The data suggested that KIF4A may play a key role in PCa progression. Notably, increased KIF4A expression may potentially predict poor BCR-free survival in PCa patients.

FKBP14 overexpression contributes to osteosarcoma carcinogenesis and indicates poor survival outcome

The FK506-binding protein 14 (FKBP14) is a subfamily of immunophilins, has been implicated in various biochemical processes. However, its effects on the primary malignant bone tumor, osteosarcoma, are unclear. Here, we reported that FKBP14 may be an oncogene as it overexpressed in osteosarcoma tissues and cell lines, and FKBP14 expression was correlated with metastases, recurrence, tumor maximum diameter and poor survival time. FKBP14 was associated with the biological pathways including cell cycle, apoptosis and metastasis. Furthermore, we detected FKBP14 knockdown induced cell cycle arrest, apoptosis, invasion and adhesion in vitro. FKBP14 knockdown decreased the protein levels of PCNA, CDK1 and CCNB1 that promotes cell cycle, increased Bax, caspase-3 and caspase-7 protein involved in promoting cell apoptosis, and increased KIF4A expression as well as decreased SMC4 and TMEM33 proteins that contribute to cell invasion and adhesion. In addition, FKBP14 knockdown also caused a significant inhibition in tumor growth in vivo. Then, we found that the protein RhoA was identified as a binding partner of FKBP14. Taken together, FKBP14 may act as an oncogene in osteosarcoma via suppressing apoptosis and promoting invasion and adhesion in osteosarcoma carcinogenesis. FKBP14 may be a prognostic factor and potential target for osteosarcoma treatment.

Enhanced expression of KIF4A in colorectal cancer is associated with lymph node metastasis

Kinesin family member 4A (KIF4A) is a member of the kinesin 4 subfamily of kinesin-related proteins and serves an important role in cell division. The expression levels of KIF4A have been investigated in numerous types of cancer, including cervical, lung, oral, and breast cancer, and are established to be associated with poor patient prognosis. However, the role of KIF4A, as well as its expression in colorectal cancer (CRC), remains to be elucidated. Therefore, the current study investigated KIF4A expression levels in patients with CRC and demonstrated that its levels were increased in tumor tissues compared with non-tumor tissues. To investigate the functional role of KIF4A, KIF4A was knocked down in CRC cells and cell viability was evaluated. CRC cells with KIF4A knockdown exhibited lower cell proliferation compared with control cells. In addition, KIF4A expression levels, as determined by immunohistochemistry, were compared with the expression of Ki-67, but no significant associations were observed in the patients with CRC. Therefore, KIF4A was found to be upregulated in patients with CRC and downregulation of KIF4A reduced cell proliferation in CRC cells. These results suggest that KIF4A may be a potential therapeutic target, which may improve the outcomes of patients with CRC.

A novel PHD-finger protein 14/KIF4A complex overexpressed in lung cancer is involved in cell mitosis regulation and tumorigenesis

The plant homeodomain (PHD) finger-containing proteins have been implicated in many human diseases including cancer. In this study, we found that PHF14, a newly identified PHD finger protein, is highly expressed in lung cancer. The high expression level of PHF14 was associated with adenocarcinoma and poor survival in lung cancer patients. Knocking down PHF14 suppressed cancer cell growth and carcinogenesis, while over-expressing PHF14 promoted cell proliferation. During cell division, PHF14 directly bound to and co-localized with KIF4A (a nuclear motor protein involved in lung carcinogenesis) to form a functional complex. Similarly to the effect of KIF4A depletion, silencing PHF14 in several cell lines caused cell mitotic defects, prolonged M phase, and inhibited cell proliferation. What's more, these two proteins had a synergistic effect on cell proliferation and were significantly co-overexpressed in lung cancer tissues. Our data provide new insights into the biological significance of PHD finger proteins and imply that PHF14 may be a potential biomarker for lung cancer.

Upregulate KIF4A Enhances Proliferation, Invasion of Hepatocellular Carcinoma and Indicates poor prognosis Across Human Cancer Types

Hepatocellular carcinoma (HCC) is one of the most aggressive and heterogeneous cancers worldwide. Herein, we demonstrate KIF4A (Chromosome-associated kinesin KIF4A) as a potential biomarker, is up-regulated in most samples of HCC. The expression level of KIF4A in tumor tissue is significantly associated with the survival time, and a significant correlation between KIF4A expression and clinical information stage, metastasis and tumor dimension was observed. We further measured the proliferation and migration ability of two HCC cell lines, HCC-LM3 and PLC/PRF/5, following KIF4A-siRNA transfection. Knocking down of KIF4A significantly reduced migration and proliferation ability. Moreover, we also measured the proliferation and migration ability of two HCC cell lines through KIF4A overexpression, and found that KIF4A overexpression could enhance migration and proliferation ability, indicating that KIF4A exhibits oncogenic effects. Besides, study based on TCGA cohorts also reveals high KIF4A mRNA expression are significantly associated with shorter overall survival in multiple cancer types. Gene sets enrichment analysis exhibited that cell cycle related pathways and p53 signaling pathways to be top altered pathways of in KIF4A-high expression group in HCC, suggesting the potential role of KIF4A in mediating tumor initiation and progression. In summary, our work identified KIF4A as a potential predictive and prognostic marker for hepatocellular carcinoma.

Kif4A mediate the accumulation and reeducation of THP-1 derived macrophages via regulation of CCL2-CCR2 expression in crosstalking with OSCC

Crosstalk between tumor infiltrating macrophages and tumor cells is thought to play an indispensable role in oral squamous cell carcinomas (OSCC) by induction and maintenance of tolerance microenvironment. High infiltration of M2 macrophages and increasing expression of Kinesin family member 4A (Kif4A) in primary OSCC have been proved to correlate with greater tumoral size and poor clinical outcome. However, linkage between Kif4A and infiltrating macrophages in tumorigenesis and progression remains unclear. In the present study, we show that, the interaction between THP-1derived macrophage and OSCC cell line Cal-27 may up-regulate the Kif4A expression in both of them. Additionally, elevated soluble CCL2 in medium and more expression of CCR2 on macrophage were observed during the crosstalk. SiRNA of Kif4A and neutralizing antibody of CCL2 were utilized to identify that; increasing Kif4A can promote the recruitment of macrophages towards Cal-27 and educate them to M2 polarized macrophages via regulating CCL2/CCR2. In combination, the results of the present study may provide interesting clues to understanding the Kif4A-CCL2/CCR2-macrophage axis as a novel therapeutic target to improve the clinical outcome of OSCC.

Molecular dysexpression in gastric cancer revealed by integrated analysis of transcriptome data

Gastric cancer (GC) is often diagnosed in the advanced stages and is associated with a poor prognosis. Obtaining an in depth understanding of the molecular mechanisms of GC has lagged behind compared with other cancers. This study aimed to identify candidate biomarkers for GC. An integrated analysis of microarray datasets was performed to identify differentially expressed genes (DEGs) between GC and normal tissues. Gene ontology and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses were then performed to identify the functions of the DEGs. Furthermore, a protein-protein interaction (PPI) network of the DEGs was constructed. The expression levels of the DEGs were validated in human GC tissues using reverse transcription-quantitative polymerase chain reaction (RT-qPCR). A set of 689 DEGs were identified in GC tissues, as compared with normal tissues, including 202 upregulated DEGs and 487 downregulated DEGs. The KEGG pathway analysis suggested that various pathways may play important roles in the pathology of GC, including pathways related to protein digestion and absorption, extracellular matrix-receptor interaction, and the metabolism of xenobiotics by cytochrome P450. The PPI network analysis indicated that the significant hub proteins consisted of SPP1, TOP2A and ARPC1B. RT-qPCR validation indicated that the expression levels of the top 10 most significantly dysexpressed genes were consistent with the illustration of the integrated analysis. The present study yielded a reference list of reliable DEGs, which represents a robust pool of candidates for further evaluation of GC pathogenesis and treatment.

Mechanisms of Chromosome Congression during Mitosis

Chromosome congression during prometaphase culminates with the establishment of a metaphase plate, a hallmark of mitosis in metazoans. Classical views resulting from more than 100 years of research on this topic have attempted to explain chromosome congression based on the balance between opposing pulling and/or pushing forces that reach an equilibrium near the spindle equator. However, in mammalian cells, chromosome bi-orientation and force balance at kinetochores are not required for chromosome congression, whereas the mechanisms of chromosome congression are not necessarily involved in the maintenance of chromosome alignment after congression. Thus, chromosome congression and maintenance of alignment are determined by different principles. Moreover, it is now clear that not all chromosomes use the same mechanism for congressing to the spindle equator. Those chromosomes that are favorably positioned between both poles when the nuclear envelope breaks down use the so-called "direct congression" pathway in which chromosomes align after bi-orientation and the establishment of end-on kinetochore-microtubule attachments. This favors the balanced action of kinetochore pulling forces and polar ejection forces along chromosome arms that drive chromosome oscillatory movements during and after congression. The other pathway, which we call "peripheral congression", is independent of end-on kinetochore microtubule-attachments and relies on the dominant and coordinated action of the kinetochore motors Dynein and Centromere Protein E (CENP-E) that mediate the lateral transport of peripheral chromosomes along microtubules, first towards the poles and subsequently towards the equator. How the opposite polarities of kinetochore motors are regulated in space and time to drive congression of peripheral chromosomes only now starts to be understood. This appears to be regulated by position-dependent phosphorylation of both Dynein and CENP-E and by spindle microtubule diversity by means of tubulin post-translational modifications. This so-called "tubulin code" might work as a navigation system that selectively guides kinetochore motors with opposite polarities along specific spindle microtubule populations, ultimately leading to the congression of peripheral chromosomes. We propose an integrated model of chromosome congression in mammalian cells that depends essentially on the following parameters: (1) chromosome position relative to the spindle poles after nuclear envelope breakdown; (2) establishment of stable end-on kinetochore-microtubule attachments and bi-orientation; (3) coordination between kinetochore- and arm-associated motors; and (4) spatial signatures associated with post-translational modifications of specific spindle microtubule populations. The physiological consequences of abnormal chromosome congression, as well as the therapeutic potential of inhibiting chromosome congression are also discussed.

Kif4 Is Essential for Mouse Oocyte Meiosis

Progression through the meiotic cell cycle must be strictly regulated in oocytes to generate viable embryos and offspring. During mitosis, the kinesin motor protein Kif4 is indispensable for chromosome condensation and separation, midzone formation and cytokinesis. Additionally, the bioactivity of Kif4 is dependent on phosphorylation via Aurora Kinase B and Cdk1, which regulate Kif4 function throughout mitosis. Here, we examine the role of Kif4 in mammalian oocyte meiosis. Kif4 localized in the cytoplasm throughout meiosis I and II, but was also observed to have a dynamic subcellular distribution, associating with both microtubules and kinetochores at different stages of development. Co-localization and proximity ligation assays revealed that the kinetochore proteins, CENP-C and Ndc80, are potential Kif4 interacting proteins. Functional analysis of Kif4 in oocytes via antisense knock-down demonstrated that this protein was not essential for meiosis I completion. However, Kif4 depleted oocytes displayed enlarged polar bodies and abnormal metaphase II spindles, indicating an essential role for this protein for correct asymmetric cell division in meiosis I. Further investigation of the phosphoregulation of meiotic Kif4 revealed that Aurora Kinase and Cdk activity is critical for Kif4 kinetochore localization and interaction with Ndc80 and CENP-C. Finally, Kif4 protein but not gene expression was found to be upregulated with age, suggesting a role for this protein in the decline of oocyte quality with age.

Increased expression of surface CD44 in hypoxia-DCs skews helper T cells toward a Th2 polarization

A low partial oxygen pressure (hypoxia) occurs in many pathological environments, such as solid tumors and inflammatory lesions. Understanding the cellular response to hypoxic stress has broad implications for human diseases. As we previously reported, hypoxia significantly altered dendritic cells (DCs) to a DC2 phenotype and promoted a Th2 polarization of naïve T cells with increased IL-4 production. However, the underlying mechanisms still remain largely unknown. In this study, we found the over-expression of surface CD44 in DCs was involved in this process via ligand binding. Further investigation showed hypoxia could reduce the surface expression of membrane type 1 metalloprotease (MT1-MMP) via down-regulating the kinesin-like protein KIF2A, which subsequently alleviated the shedding of CD44 from DCs. Moreover, KIF2A expression was found negatively regulated by HIF-1α in hypoxic microenvironment. These results suggest a previously uncharacterized mechanism by which hypoxia regulates the function of DCs via KIF2A/MT1-MMP/CD44 axis, providing critical information to understand the immune response under hypoxia.

Hepatitis B virus upregulates the expression of kinesin family member 4A

Hepatitis B virus (HBV) infection is one of the major causes of hepatocellular carcinoma (HCC). Kinesin family member 4A (KIF4A) is a microtubule‑based motor protein, which is upregulated in cervical and lung cancer. However, the expression of KIF4A in HBV‑associated HCC, and the effect of HBV on the expression of KIF4A remain to be elucidated. In the present study, the expression profiles of KIF4A were examined in cancerous tissues and paracancerous tissues from patients with HCC, who presented with histories of chronic HBV infection, and the role of HBV in the induction of the expression of KIF4A was investigated. HepG2 cells were transfected with the pHBV1.3, HBV infectious clone and a construct, which contained the luciferase gene under the control of the KIF4A gene promoter. The results demonstrated that the expression of KIF4A was significantly higher in the HCC tissues than in the paracancerous tissues. HBV activated the KIF4A gene promoter and upregulated the mRNA and protein expression of KIF4A. Furthermore, activation of the gene expression of KIF4A increased in a pHBV1.3 concentration‑dependent manner. These results provide novel insights into the understanding of HCC oncogenesis caused by HBV.

Kinesin family member 4A: a potential predictor for progression of human oral cancer

BACKGROUND

Kinesin family member 4A (KIF4A), a microtubule-based motor protein, was implicated in regulation of chromosomal structure and kinetochore microtubule dynamics. Considering the functions of KIF4A, we assumed that KIF4A is involved in progression of oral squamous cell carcinomas (OSCCs) via activation of the spindle assembly checkpoint (SAC). However, little is known about the relevance of KIF4A in the behavior of OSCC. We investigated the KIF4A expression status and its functional mechanisms in OSCC.

METHODS

The KIF4A expression levels in seven OSCC-derived cells were analyzed by quantitative reverse transcriptase-polymerase chain reaction and immunoblotting analyses. Using a KIF4A knockdown model, we assessed the expression of (SAC)-related molecules (BUB1, MAD2, CDC20, and cyclin B1), cell-cycle, and cellular proliferation. In addition to in vitro data, the clinical correlation between the KIF4A expression levels in primary OSCCs (n = 106 patients) and the clinicopathologic status by immunohistochemistry (IHC) also were evaluated.

RESULTS

KIF4A mRNA and protein were up-regulated significantly (P < 0.05) in seven OSCC-derived cells compared with human normal oral keratinocytes. In the KIF4A knockdown cells, SAC activation was observed via increased BUB1 expression on the kinetochores, appropriate kinetochore localization of MAD2, down-regulation of CDC20, up-regulation of cyclin B1, and cell-cycle arrested at G2/M phase. The results showed that cellular proliferation of KIF4A knockdown cells decreased significantly (P < 0.05) compared with control cells. IHC showed that KIF4A expression in primary OSCCs was significantly (P < 0.05) greater than in the normal oral counterparts and that KIF4A-positive OSCCs were correlated closely (P < 0.05) with tumoral size.

CONCLUSIONS

Our results proposed for the first time that KIF4A controls cellular proliferation via SAC activation. Therefore, KIF4A might be a key regulator for tumoral progression in OSCCs.

The motor protein KIF14 inhibits tumor growth and cancer metastasis in lung adenocarcinoma

The motor protein kinesin superfamily proteins (KIFs) are involved in cancer progression. The depletion of one of the KIFs, KIF14, might delay the metaphase-to-anaphase transition, resulting in a binucleated status, which enhances tumor progression; however, the exact correlation between KIF14 and cancer progression remains ambiguous. In this study, using loss of heterozygosity and array comparative genomic hybridization analyses, we observed a 30% loss in the regions surrounding KIF14 on chromosome 1q in lung adenocarcinomas. In addition, the protein expression levels of KIF14 in 122 lung adenocarcinomas also indicated that approximately 30% of adenocarcinomas showed KIF14 down-regulation compared with the expression in the bronchial epithelial cells of adjacent normal counterparts. In addition, the reduced expression of KIF14 mRNA or proteins was correlated with poor overall survival (P = 0.0158 and <0.0001, respectively), and the protein levels were also inversely correlated with metastasis (P<0.0001). The overexpression of KIF14 in lung adenocarcinoma cells inhibited anchorage-independent growth in vitro and xenograft tumor growth in vivo. The overexpression and silencing of KIF14 also inhibited or enhanced cancer cell migration, invasion and adhesion to the extracellular matrix proteins laminin and collagen IV. Furthermore, we detected the adhesion molecules cadherin 11 (CDH11) and melanoma cell adhesion molecule (MCAM) as cargo on KIF14. The overexpression and silencing of KIF14 enhanced or reduced the recruitment of CDH11 in the membrane fraction, suggesting that KIF14 might act through recruiting adhesion molecules to the cell membrane and modulating cell adhesive, migratory and invasive properties. Thus, KIF14 might inhibit tumor growth and cancer metastasis in lung adenocarcinomas.

Oncogenic role of kinesin proteins and targeting kinesin therapy

The kinesin superfamily (KIF) is a group of proteins that share a highly conserved motor domain. Except for some members, many KIF proteins have adenosine triphosphatase activity and microtubule-dependent plus-end motion ability. Kinesins participate in several essential cellular functions, including mitosis, meiosis and the transport of macromolecules. Increasing evidence indicates kinesin proteins play critical roles in the genesis and development of human cancers. Some kinesin proteins are associated with maligancy as well as drug resistance of solid tumor. Thus, targeting KIF therapy seems to be a promising anticancer strategy. Inhibitors of KIF such as kinesin spindle protein (KSP/Eg5) have entered clinical trials for monotherapy or in combination with other drugs, and kinesins other than Eg5 with various potential anticancer target characteristics are also constantly being discovered and studied. Here, we summarize the oncogenic roles of kinesin proteins and potential cancer therapy strategies that target KIF.

Human chromokinesins promote chromosome congression and spindle microtubule dynamics during mitosis

Human chromokinesins hKID and KIF4A contribute to proper attachment of chromosomes by controlling the positioning of the chromosome arms and microtubule dynamics, respectively.

Chromokinesins are microtubule plus end–directed motor proteins that bind to chromosome arms. In Xenopus egg cell-free extracts, Xkid and Xklp1 are essential for bipolar spindle formation but the functions of the human homologues, hKID (KIF22) and KIF4A, are poorly understood. By using RNAi-mediated protein knockdown in human cells, we find that only co-depletion delayed progression through mitosis in a Mad2-dependent manner. Depletion of hKID caused abnormal chromosome arm orientation, delayed chromosome congression, and sensitized cells to nocodazole. Knockdown of KIF4A increased the number and length of microtubules, altered kinetochore oscillations, and decreased kinetochore microtubule flux. These changes were associated with failures in establishing a tight metaphase plate and an increase in anaphase lagging chromosomes. Co-depletion of both chromokinesins aggravated chromosome attachment failures, which led to mitotic arrest. Thus, hKID and KIF4A contribute independently to the rapid and correct attachment of chromosomes by controlling the positioning of chromosome arms and the dynamics of microtubules, respectively.

Leptin-mediated regulation of MT1-MMP localization is KIF1B dependent and enhances gastric cancer cell invasion

Leptin overexpression is closely correlated with gastric cancer (GC) invasion, but its exact effect and the underlying mechanism in tumorigenesis remain poorly understood. Membrane type 1-matrix metalloproteinase (MT1-MMP), a surface-anchored 'master switch' proteinase, is overexpressed and plays crucial roles in tumor invasion. Here, we characterized the influence of leptin on the generation and surface localization of MT1-MMP in GC and elucidated its molecular mechanisms. Our results revealed that leptin promoted GC cell invasion in vitro by upregulating MT1-MMP expression. Furthermore, cell surface biotinylation assay and flow cytometry demonstrated that the surface expression of MT1-MMP was also enhanced by leptin, and knockdown of kinesin family member 1B (KIF1B, a microtubule plus end-directed monomeric motor protein) by small interference RNA inhibited this process. Notably, coimmunoprecipitation analysis indicated that leptin enhanced the interaction of MT1-MMP with KIF1B in a time-dependent manner, which consequently contributed to GC cell invasion. Moreover, leptin increased MT1-MMP or KIF1B expression by the protein kinase B (AKT) pathway and extracellular signal-regulated kinase 1/2 partially participated in this process. However, only AKT was implicated in the leptin-mediated membrane localization of MT1-MMP. Immunohistochemistry analysis revealed that leptin, MT1-MMP and KIF1B are overexpressed in GC tissues, and they positively correlated with clinical stage and lymph node metastasis. These observations indicate that this regulatory network exists in vivo. Taken together, our findings suggest that leptin is an effective intracellular stimulator of MT1-MMP and that leptin-enhanced cell surface localization of MT1-MMP is dependent on KIF1B, which consequently plays a critical role in GC invasion.

Kinesins and cancer

Kinesins are a family of molecular motors that travel unidirectionally along microtubule tracks to fulfil their many roles in intracellular transport or cell division. Over the past few years kinesins that are involved in mitosis have emerged as potential targets for cancer drug development. Several compounds that inhibit two mitotic kinesins (EG5 (also known as KIF11) and centromere-associated protein E (CENPE)) have entered Phase I and II clinical trials either as monotherapies or in combination with other drugs. Additional mitotic kinesins are currently being validated as drug targets, raising the possibility that the range of kinesin-based drug targets may expand in the future.