Increased expression of KPNA2 predicts unfavorable prognosis in ovarian cancer patients, possibly by targeting KIF4A signaling.

BACKGROUND: Karyopherin α-2 (KPNA2) is a member of karyopherin family, which is proved to be responsible for the import or export of cargo proteins. Studies have determined that KPNA2 is associated with the development and prognosis of various cancers, yet the role of KPNA2 in ovarian carcinoma and its potential molecular mechanisms remains unclear. MATERIALS AND METHODS: The expression and prognosis of KPNA2 in ovarian cancer was investigated using GEPIA and Oncomine analyses. Mutations of KPNA2 in ovarian cancer were analyzed by cBioPortal database. The prognostic value of KPNA2 expression was evaluated by our own ovarian carcinoma samples using RT-qPCR. Subsequently, the cell growth, migration and invasion of ovarian cancer cells were investigated by CCK-8 and transwell assay, respectively. The protein levels of KPNA2 and KIF4A were determined by western blot. RESULTS: We obtained the following important results. (1) KPNA2 and KIF4A wereoverexpressed in ovairan cancer tissues and cells. (2) Among patients with ovarian cancer, overexpressed KPNA2 was associated with lower survival rate. (3) Mutations (R197* and S140F) in KPNA2 will have some influences on protein structure, and then may cause protein function abnormal. (4) KPNA2 konckdown inhibited proliferation, migration, invasion, as well as the expression of KIF4A. CONCLUSION: KPNA2, as a tumorigenic gene in ovarian cancer, accelerated tumor progression by up-regulating KIF4A, suggesting that KPNA2 might be a hopeful indicator of treatment and poor prognosis.

Cold-induction of afadin in brown fat supports its thermogenic capacity.

The profound energy-expending nature of brown adipose tissue (BAT) thermogenesis makes it an attractive target tissue to combat obesity-associated metabolic disorders. While cold exposure is the strongest inducer of BAT activity, the temporal mechanisms tuning BAT adaptation during this activation process are incompletely understood. Here we show that the scaffold protein Afadin is dynamically regulated by cold in BAT, and participates in cold acclimation. Cold exposure acutely increases Afadin protein levels and its phosphorylation in BAT. Knockdown of Afadin in brown pre-adipocytes does not alter adipogenesis but restricts ß3-adrenegic induction of thermogenic genes expression and HSL phosphorylation in mature brown adipocytes. Consistent with a defect in thermogenesis, an impaired cold tolerance was observed in fat-specific Afadin knockout mice. However, while Afadin depletion led to reduced Ucp1 mRNA induction by cold, stimulation of Ucp1 protein was conserved. Transcriptomic analysis revealed that fat-specific ablation of Afadin led to decreased functional enrichment of gene sets controlling essential metabolic functions at thermoneutrality in BAT, whereas it led to an altered reprogramming in response to cold, with enhanced enrichment of different pathways related to metabolism and remodeling. Collectively, we demonstrate a role for Afadin in supporting the adrenergic response in brown adipocytes and BAT function.

High KIFC1 expression is associated with poor prognosis in prostate cancer.

Kinesins play important roles in the progression and development of cancer. Kinesin family member C1 (KIFC1), a minus end-directed motor protein, is a novel Kinesin involved in the clustering of excess centrosomes found in cancer cells. Recently KIFC1 has shown to play a role in the progression of many different cancers, however, the involvement of KIFC1 in the progression of prostate cancer (PCa) is still not well understood. This study investigated the expression and clinical significance of KIFC1 in PCa by utilizing multiple publicly available datasets to analyze KIFC1 expression in patient samples. High KIFC1 expression was found to be associated with high Gleason score, high tumor stage, metastatic lesions, high ploidy levels, and lower recurrence-free survival. These results reveal that high KIFC1 levels are associated with a poor prognosis for PCa patients and could act as a prognostic indicator for PCa patients as well.

miR-340 Exerts Suppressive Effect on Retinoblastoma Progression by Targeting KIF14.

Purpose: This work aimed to investigate the influences of microRNA-340 (miR-340) on proliferation and apoptosis of retinoblastoma (RB) cells and explore its regulatory mechanism. MATERIALS AND METHODS: miR-340 mimic and inhibitor were applied for up-regulating or inhibiting the expression of miR-340 in RB cell lines. Then, CCK-8 and AnnexinV-FITC/PI staining were used to measure cell proliferation and apoptosis, respectively. After that, luciferase assay was performed to affirm the direct targets of miR-340. Furthermore, qRT-PCR and western blotting assay were carried out to detect the levels of miR-340 and KIF14. RESULTS: Our results indicated that the miR-340 was lowly expressed in RB cell lines, and up-regulation of miR-340 can decrease the proliferation and induce the apoptosis of RB cells. Moreover, we verified that miR-340 controls KIF14 expression, either directly or through a subsequent molecular cascade, and inversely related to its expression. The results obtained from the rescue assays presented that over-expression of KIF14 reversed the miR-340-mediated inhibition on malignant phenotype of RB cells. CONCLUSIONS: Overall, we proved that miR-340 can decrease the proliferation and increase the apoptosis of RB cells, and its function in RB cells was at least partially achieved via down-regulation of KIF14, prompting that miR-340 was expected to supply a new direction for clinical therapy of RB in the future.

Long Non-Coding RNA Paternally Expressed Imprinted Gene 10 (PEG10) Elevates Diffuse Large B-Cell Lymphoma Progression by Regulating Kinesin Family Member 2A (KIF2A) via Targeting MiR-101-3p.

BACKGROUND Diffuse large B-cell lymphoma (DLBCL) is a common malignant tumor in the immune system with high mortality. We investigated the functional effects of long non-coding RNA paternally expressed imprinted gene 10 (PEG10) on DLBCL progression. MATERIAL AND METHODS Real-time quantitative polymerase chain reaction was used to measure the level of PEG10, kinesin family member 2A (KIF2A) and microRNA-101-3p (miR-101-3p) in DLBCL tissues and cell lines. The relative protein level was detected by western blot analysis. The biological behaviors including cell proliferation, apoptosis, migration, and invasion were determined by MTT assay, flow cytometry analysis, and Transwell assays, respectively. Bioinformatics analysis and dual-luciferase reporter assay were performed to evaluate the interaction among PEG10, miR-101-3p, and KIF2A. RESULTS PEG10 and KIF2A level were significantly upregulated, while miR-101-3p was downregulated in DLBCL tissues and cells. PEG10 positively regulated KIF2A level in DLBCL. PEG10, or KIF2A deletion significantly inhibited the proliferative, migratory, and invasive abilities of DLBCL cells and elevated cell apoptosis in DLBCL cells. KIF2A upregulation partially reversed the effects of PEG10 downregulation on cell growth, metastasis, and apoptosis in DLBCL. Moreover, PEG10 negatively regulated miR-101-3p level and miR-101-3p upregulation exerted inhibition effects on the progression of DLBCL. Besides, miR-101-3p was a target of PEG10 and miR-101-3p could directly target KIF2A. PEG10 promoted KIF2A level by sponging miR-101-3p. CONCLUSIONS Our findings revealed that PEG10 played an oncogenic role in DLBCL progression, which might be a potential target for the treatment of DLBCL.

Human papillomavirus 16 (HPV 16) E6 but not E7 inhibits the antitumor activity of LKB1 in lung cancer cells by downregulating the expression of KIF7.

BACKGROUND: The E6 and E7 proteins in human papillomavirus 16 (HPV 16) are the main oncogenes in the occurrence of lung cancer. In recent studies, we found that E6 and E7 downregulated the expression of LKB1 in lung cancer cells. However, it is still unclear how E6 and E7 regulate LKB1 in lung cancer cells. METHODS: Double directional genetic manipulation and nuclear plasma separation technology were performed to explore the molecular mechanism of E6 and E7 inhibiting the antitumor activity of LKB1 in well-established lung cancer cell lines. RESULTS: E6 but not E7 significantly downregulated the expression of tumor suppressor KIF7 at protein level, and the inhibition of KIF7 further reduced the expression of LKB1 both in the nuclei and in the cytoplasm, whereas reduced the expression of p-LKB1 in the cytoplasm only. This suggested that HPV 16 E6 but not E7 downregulates the antitumor activity of LKB1 by downregulating the expression of p-LKB1 in the cytoplasm only. CONCLUSIONS: Here, we demonstrated for the first time that E6 but not E7 inhibits the antitumor activity of LKB1 in lung cancer cells by downregulating the expression of KIF7. Our findings provide new evidence to support the important role of KIF7 in the pathogenesis of lung cancer and suggests new therapeutic targets.

An interphase pool of KIF11 localizes at the basal bodies of primary cilia and a reduction in KIF11 expression alters cilia dynamics.

KIF11 is a homotetrameric kinesin that peaks in protein expression during mitosis. It is a known mitotic regulator, and it is well-described that KIF11 is necessary for the formation and maintenance of the bipolar spindle. However, there has been a growing appreciation for non-mitotic roles for KIF11. KIF11 has been shown to function in such processes as axon growth and microtubule polymerization. We previously demonstrated that there is an interphase pool of KIF11 present in glioblastoma cancer stem cells that drives tumor cell invasion. Here, we identified a previously unknown association between KIF11 and primary cilia. We confirmed that KIF11 localized to the basal bodies of primary cilia in multiple cell types, including neoplastic and non-neoplastic cells. Further, we determined that KIF11 has a role in regulating cilia dynamics. Upon the reduction of KIF11 expression, the number of ciliated cells in asynchronously growing populations was significantly increased. We rescued this effect by the addition of exogenous KIF11. Lastly, we found that depleting KIF11 resulted in an increase in cilium length and an attenuation in the kinetics of cilia disassembly. These findings establish a previously unknown link between KIF11 and the dynamics of primary cilia and further support non-mitotic functions for this kinesin.

Kolavenic acid analog restores growth in HSET-overproducing fission yeast cells and multipolar mitosis in MDA-MB-231 human cells.

Although cancer cells often harbor supernumerary centrosomes, they form pseudo-bipolar spindles via centrosome clustering, instead of lethal multipolar spindles, and thus avoid cell death. Kinesin-14 HSET/KIFC1 is a crucial protein involved in centrosome clustering. Accordingly, a compound that targets HSET could potentially inhibit cancer cell proliferation in a targeted manner. Here, we report three natural compounds derived from Solidago altissima that restored the growth of fission yeast cells exhibiting lethal HSET overproduction (positive screening), namely solidagonic acid (SA) (1), kolavenic acid analog (KAA: a stereo isomer at C-9 and C-10 of 6ß-tigloyloxykolavenic acid) (2), and kolavenic acid (KA) (3). All three compounds suppressed fission yeast cell death and enabled reversion of the mitotic spindles from a monopolar to bipolar morphology. Compound 2, which exerted the strongest activity against HSET-overproducing yeast cells, also inhibited centrosome clustering in MDA-MB-231 human breast adenocarcinoma cells, which contained large numbers of supernumerary centrosomes. These natural compounds may be useful as bioprobes in studies of HSET function. Moreover, compound 2 is a prime contender in the development of novel agents for cancer treatment.

KIF2 mediates the neuroprotection in cerebral ischaemia injury by affecting NF-κB pathway.

Stroke is the most common cerebrovascular disease with high morbidity and mortality around the world. However, the underlying mechanisms involved in nerve injury and cerebral ischaemia/reperfusion (I/R) during cerebrovascular disease are still not completely clear. In the present study, we investigate the role of kinesin family member 2 (KIF2) in the neuroprotection after cerebral I/R injury. KIF2 was aberrantly expressed in the cerebral tissues from middle cerebral artery occlusion (MCAO) rat model in a time dependent manner. A similar changing pattern was found in the cultured hypoxic neurons as well as SK-N-SH cells in vitro. Compared to the control, KIF2 inhibition significantly increased the level of malonic dialdehyde (MDA), and reduced the level of superoxide dismutase (SOD) as well as glutathione peroxidase (GSH-px) activity in cerebral tissues of MCAO rat model. The reactive oxygen species (ROS) level was also up-regulated after KIF2 siRNA knockdown in cultured hypoxic SK-N-SH cells. The apoptosis rates of hypoxic neurons and SK-N-SH cells as well as activated-caspase-3 level were obviously increased after KIF2 silencing. Furthermore, we found that the nuclear factor-kappa B (NF-κB) pathway was involved in KIF2-mediated neuroprotection after cerebral I/R injury, and induced apoptosis of hypoxic SK-N-SH cells by KIF2 silencing could be attenuated by the specific inhibitor BAY11-7082 of NF-κB. In conclusion, we demonstrate that KIF2 could mediate the neuroprotection in cerebral I/R injury by inhibiting activation of NF-κB pathway. This might provide a novel therapeutic target for cerebral I/R injury.

Bioinformatics Analysis Suggests the Combined Expression of AURKB and KIF18B Being an Important Event in the Development of Clear Cell Renal Cell Carcinoma.

Clear cell renal cell carcinoma (ccRCC) is the most common type of renal cell carcinoma with high metastatic rate and high mortality rate, needing to find potential therapeutic targets and develop new therapy methods. The bioinformatics analysis was used in this study to find the targets. Firstly, the expression profile of ccRCC obtained from The Cancer Genome Atlas (TCGA) database and GSE53757 dataset were used to identify the significant up-regulated genes. IL20RB, AURKB and KIF18B with the top efficiency of capable of diagnosis ccRCC from para cancer tissue, were over-expressed in ccRCC samples, and expressed increasedly with the development of ccRCC. There was the closest correlation between AURKB and KIF18B in these three over-expressed genes. AURKB (high) or KIF18B (high) were all significantly correlated with higher T, N, M stage, G grade and shorter overall survival (OS) of ccRCC patients. Furthermore, the ccRCC patients with AURKB (high) + KIF18B (high) showed worse clinical characteristics and prognosis. Multivariate COX regression analysis indicated AURKB (high) and KIF18B (high) were all the independent prognostic risk factor without considering the interaction of AURKB and KIF18B. Moreover, considering the combination of each other, only AURKB (high) + KIF18B (high) expression was an independent prognostic risk factor for ccRCC patients, but not other situations. Collectively, AURKB was closely associated with KIF18B, and the combined expression of AURKB and KIF18B may be of great significance in ccRCC.

Suppression of KIF22 Inhibits Cell Proliferation and Xenograft Tumor Growth in Colon Cancer.

Background: Kinesin family member 22 (KIF22) is known as a regulator of cell mitosis and cellular vesicle transport. The alterations of KIF22 are associated with a series of tumors; however, its possible role in the progression of colon cancer is still unclear. Materials and Methods: This retrospective research collected 82 paired tissues with colon cancer. KIF22 protein and mRNA expression levels were detected by immunohistochemistry assays and Immunoblot assays, respectively. Short hairpin RNA (shRNA) plasmids were used to suppress the expression of KIF22 in HCT116 and HT29 cells, and the silencing efficiencies of shRNA plasmids targeted KIF22 were detected by quantitative PCR assays and immunoblot assays. In addition, 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) assays and xenograft tumor growth assays were performed to observe cell proliferation in vitro and in vivo. Results: In human colon cancer tissues, the expression level of KIF22 was increased and correlated with clinical pathological features, including tumor stage and clinical stage (p = 0.034, and p = 0.015, respectively). Suppression of KIF22 inhibited cell proliferation and xenograft tumor growth. Conclusion: KIF22 might play an important role in the regulation of cell proliferation in colon cancer and might therefore serve as a promising therapeutic target.

Prognostic significance of KIF2A and KIF20A expression in human cancer: A systematic review and meta-analysis.

BACKGROUND: The kinesin family (KIF) is reported to be aberrantly expressed and significantly correlated with survival outcomes in patients with various cancers. This meta-analysis was carried out to quantitatively evaluate the prognostic values of partial KIF members in cancer patients. METHODS: Two well-known KIF members, KIF2A and KIF20A, were investigated to evaluate their potential values as novel prognostic biomarkers in human cancer. A comprehensive literature search was carried out of the PubMed, EMBASE, Cochrane Library, and Web of Science databases up to April 2019. Pooled hazard ratios (HRs) and odds ratios (ORs) with 95% confidence intervals (CIs) were calculated to assess the association of KIF2A and KIF20A expression with overall survival (OS) and clinicopathological parameters. RESULTS: Twenty-five studies involving 7262 patients were finally incorporated, including nine about KIF2A and sixteen about KIF20A. Our results indicated that patients with high expression of KIF2 and KIF20A tended to have shorter OS than those with low expression (HR = 2.23, 95% CI = 1.87-2.65, P < .001; HR = 1.77, 95% CI = 1.57-1.99, P < .001, respectively). Moreover, high expression of these 2 KIF members was significantly associated with advanced clinical stage (OR = 1.98, 95% CI: 1.57-2.50, P < .001; OR = 2.63, 95% CI: 2.03-3.41, P < .001, respectively), positive lymph node metastasis (OR = 2.32, 95% CI: 1.65-3.27, P < .001; OR = 2.13, 95% CI: 1.59-2.83, P < .001, respectively), and distant metastasis (OR = 2.20, 95% CI: 1.21-3.99, P = .010; OR = 5.25, 95% CI: 2.82-9.77, P < .001, respectively); only high KIF20A expression was related to poor differentiation grade (OR = 1.82, 95% CI: 1.09-3.07, P = .023). CONCLUSIONS: High expression of KIF2 and KIF20A in human cancer was significantly correlated with worse prognosis and unfavorable clinicopathological features, suggesting that these 2 KIF members can be used as prognostic biomarkers for different types of tumors. PROSPERO REGISTRATION NUMBER: CRD42019134928.

Low expression of KIF7 indicates poor prognosis in epithelial ovarian cancer.

The aim of the present study was to investigate kinesin family member 7 (KIF7) expression in epithelial ovarian cancer tissues (paraffin-embedded tissues and fresh) and to explore its expression, association with clinicopathological parameters and prognostic value in patients with epithelial ovarian cancer. A total of 113 paraffin-embedded tumor tissues of epithelial ovarian cancer patients diagnosed and operated at the memorial hospital of Sun Yat-sen University Between December 2009 and March 2017 and 41 paratumor tissues were collected for the present study and were assessed for KIF7 expression using immunohistochemistry. Furthermore, 22 fresh epithelial ovarian cancer tissues and their matched paratumor tissues were collected from the Integrated Hospital of Traditional Chinese Medicine, Southern Medical University, between August 2013 and March 2019 and subjected to reverse-transcription quantitative PCR analysis to detect the mRNA expression of KIF7. The expression of KIF7 was lower in cancer tissues than in paratumor tissues, and KIF7 expression was associated with recurrence-free survival and overall survival in epithelial ovarian cancer patients. Furthermore, multivariate logistic regression analysis indicated that low KIF7 expression was an independent predictor of poor survival in patients with epithelial ovarian cancer. In conclusion, KIF7 has a tumor suppressor role in epithelial ovarian cancer and is a useful independent prognostic predictor. It may hold important value for the clinical diagnosis and treatment of epithelial ovarian cancer.

Prognostic and clinicopathological significance of kinesin family member C1 in various cancers: A meta-analysis.

BACKGROUND: Kinesin family member C1 (KIFC1), a C-type kinesin motor protein, plays important roles in centrosome assembly and intracellular transport. Numerous studies have focused on the prognostic value of KIFC1 in malignant tumors and the relationship between KIFC1 expression and clinicopathological traits of cancer patients, but the studies remain controversial. And no meta-analysis has yet shown the association between KIFC1 and various cancers. METHODS: Systematic retrieval was carried out within several databases, including PubMed, Embase, Web of Science, Wanfang and China National Knowledge Infrastructure (CNKI). In addition, hazard ratios (HR) and relative risks (RR) with 95% confidence intervals (CIs) were calculated to examine the risk or hazard correlation by Stata SE15.1. RESULTS: Eleven studies with the overall 2424 participants were included in this research. High KIFC1 expression was remarkably correlated with worse OS (HR = 1.33, 95% CI = 1.07-1.60) and poorer relapse-free survival (HR = 2.28, 95% CI = 1.75-2.80). In subgroup analysis, high KIFC1 expression was a negative predictor for OS in patients with ovarian cancer (P < .001), breast cancer (P < .001), hepatocellular carcinoma (P < .001), and non-small cell lung cancer (P < .001), but not for esophageal squamous cell carcinoma (P = .246). Moreover, high levels of KIFC1 were related with positive lymph node metastasis (RR = 1.23, 95% CI = 1.01-1.50, P = .041) and advanced tumor node metastasis (TNM) stage (RR = 1.55, 95% CI = 1.27-1.89, P < .001). CONCLUSIONS: KIFC1 overexpression indicates poor prognosis and more serious clinicopathological characteristics in kinds of malignancies. Thus, we conclude that KIFC1 could be a target for clinical diagnosis and treatment of various cancers.

Systemic delivery of Eg5 shRNA-expressing plasmids using PEGylated DC-Chol/DOPE cationic liposome: Long-term silencing and anticancer effects in vivo.

Duration of gene silencing due to the short-term silencing effects induced by exogenous siRNA have limited the therapeutic applications of RNAi and the development of RNAi-based therapeutics. We here generated Eg5 shRNA-expressing plasmids using the inverted terminal repeats (ITRs) sequences to produce Eg5 hairpin RNA under the control of U6 promoter. Using PEGylated DC-Chol/DOPE cationic liposomes, we demonstrated that a single systemic administration of Eg5 shRNA-expressing plasmid/liposome lipoplexes induced the long-term Eg5 silencing in the tumor sites of tumor-bearing mice, and ultimately lead to more sustained anticancer effects than standard synthetic siEg5/liposome lipoplexes. This non-viral Eg5 shRNA expression system had no risk of immunogenicity anticipated in the use of viral vectors, and could reduce the potential of off-target effects by scaling down the administration dose of RNAi therapeutics in patient. Therefore, the sustainable shRNA expression properties in the tumor sites suggest an efficient strategy to overcome the limitations caused by chemically synthesized siRNA methods such as short-term silencing effects and off-target effects. Herein, this study provides a non-viral silencing strategy for inducing long-term Eg5 silencing in vivo and suggests the great potential of Eg5 shRNA-expressing lipoplexes as a DNA-based RNAi therapeutics for cancer treatment.

Fission yeast cells overproducing HSET/KIFC1 provides a useful tool for identification and evaluation of human kinesin-14 inhibitors.

Many human cancer cells contain more than two centrosomes, yet these cancer cells can form pseudo-bipolar spindles through the mechanism, called centrosome clustering, and survive, instead of committing lethal multipolar mitoses. Kinesin-14/HSET, a minus end-directed motor, plays a crucial role in centrosome clustering. Accordingly, HSET is deemed to be a promising chemotherapeutic target to selectively kill cancer cells. Recently, three HSET inhibitors (AZ82, CW069 and SR31527) have been reported, but their specificity and efficacy have not been evaluated rigorously. This downside partly stems from the lack of robust systems for the assessment of these drugs. Yeasts and filamentous fungi provide not only powerful models for basic and applied biology but also versatile tools for drug discovery and evaluation. Here we show that these three inhibitors on their own are cytotoxic to fission yeast, suggesting that they have off-targets in vivo except for kinesin-14. Nonetheless, intriguingly, AZ82 can neutralize otherwise toxic overproduced HSET; this includes a substantial reduction in the percentage of HSET-driven abnormal mitotic cells and partial suppression of its lethality. SR31527 also displays modest neutralizing activity, while we do not detect such activity in CW069. As an experimental proof-of-principle study, we have treated HSET-overproducing fission yeast cells with extracts prepared from various plant species and found activities that rescue HSET-driven lethality in those from Chamaecyparis pisifera and Toxicodendron trichocarpum. This methodology of protein overproduction in fission yeast, therefore, provides a convenient, functional assay system by which to screen for not only selective human kinesin-14 inhibitors but also those against other molecules of interest.

Axonal transport proteins and depressive like behavior, following Chronic Unpredictable Mild Stress in male rat.

BACKGROUND: A common mood disorder, depression has long been considered a leading cause of disability worldwide. Chronic stress is involved in the development of various psychiatric diseases including major depressive disorder. Stress can induce depressive-like symptoms and initiate neurodegenerative processes in the brain. The neurodegenerative theory of depression holds impaired axonal transport as a negative factor in neural survival. Axonal transport is a critical mechanism for normal neuronal function, playing crucial roles in axon growth, neurotransmitter secretion, normal mitochondrial function and neural survival. METHODS AND MATERIALS: To investigate the effects of stress-induced depression, in the present study, we evaluated behavior by forced swimming test (FST), corticosterone plasma level by ELISA assay, hippocampal mRNA expression of three genes (NGF, kinesin and dynein) via real-time PCR and hippocamp count by Nissl staining in male Wistar rats. RESULTS: Our data demonstrated a significant decrease in the expression of NGF, kinesin and dynein genes in CUMS groups compared to the control group (non-stressed) (p < 0.05). CUMS also caused an elevation in immobility time and corticosterone plasma level in the stressed group compared to the controls (p < 0.01 and p < 0.05, respectively). CONCLUSION: The results suggested that the possibility of stress-induced depressive behavior associated with hippocampal neurodegeneration process is correlated with a low expression of kinesin and dynein, the two most important proteins in axonal transport.

Role of hypoxia in Diffuse Large B-cell Lymphoma: Metabolic repression and selective translation of HK2 facilitates development of DLBCL.

Published molecular profiling studies in patients with lymphoma suggested the influence of hypoxia inducible factor-1 alpha (HIF1α) targets in prognosis of DLBCL. Yet, the role of hypoxia in hematological malignancies remains unclear. We observed that activation of HIF1α resulted in global translation repression during hypoxic stress in DLBCL. Protein translation efficiency as measured using 35S-labeled methionine incorporation revealed a ≥50% reduction in translation upon activation of HIF1α. Importantly, translation was not completely inhibited and expression of clinically correlated hypoxia targets such as GLUT1, HK2, and CYT-C was found to be refractory to translational repression under hypoxia in DLBCL cells. Notably, hypoxic induction of these genes was not observed in normal primary B-cells. Translational repression was coupled with a decrease in mitochondrial function. Screening of primary DLBCL patient samples revealed that expression of HK2, which encodes for the enzyme hexokinase 2, was significantly correlated with DLBCL phenotype. Genetic knockdown studies demonstrated that HK2 is required for promoting growth of DLBCL under hypoxic stress. Altogether, our findings provide strong support for the direct contribution of HK2 in B-cell lymphoma development and suggest that HK2 is a key metabolic driver of the DLBCL phenotype.

Characterization of KIF11 as a novel prognostic biomarker and therapeutic target for oral cancer.

Oral cancer has a high mortality rate, and its incidence is increasing gradually worldwide. As the effectiveness of standard treatments is still limited, the development of new therapeutic strategies is eagerly awaited. Kinesin family member 11 (KIF11) is a motor protein required for establishing a bipolar spindle in cell division. The role of KIF11 in oral cancer is unclear. Therefore, the present study aimed to assess the role of KIF11 in oral cancer and evaluate its role as a prognostic biomarker and therapeutic target for treating oral cancer. Immunohistochemical analysis demonstrated that KIF11 was expressed in 64 of 99 (64.6%) oral cancer tissues but not in healthy oral epithelia. Strong KIF11 expression was significantly associated with poor prognosis among oral cancer patients (P=0.034), and multivariate analysis confirmed its independent prognostic value. In addition, inhibition of KIF11 expression by transfection of siRNAs into oral cancer cells or treatment of cells with a KIF11 inhibitor significantly suppressed cell proliferation, probably through G2/M arrest and subsequent induction of apoptosis. These results suggest that KIF11 could be a potential prognostic biomarker and therapeutic target for oral cancer.

Tumor suppressor protein p53-mediated repression of human mitotic centromere-associated kinesin gene expression is exerted via down-regulation of Sp1 level.

The repressive role of p53 on the human mitotic centromere-associated kinesin (MCAK) core promoter from ‒266 to +54, relative to the transcription start site, has been determined. The MCAK mRNA and protein levels were 2.1- and 3.0-fold higher, respectively, in HCT116 (p53‒/‒) than in HCT116 (p53+/+) cells. Enforced down-regulation of p53 levels either in HCT116 (p53+/+) cells by p53 RNAi treatment or in MCF-7 cells using shRNA for p53 (shp53) resulted in a remarkable increase in the MCAK protein level. Site-directed mutagenesis and ChIP analyses showed that p53-mediated repression of the MCAK core promoter activity was not directly exerted by p53-binding to putative p53-response elements (p53-RE1 at -173/-166 and p53-RE2 at -245/-238), but indirectly by attenuating Sp1 binding to GC-motifs (GC1 at -93/-84 and GC2 at -119/-110). Treatment of HEK-293 cells bearing the MCAK core promoter-reporter (pGL2-320-Luc) with mithramycin A, which down-regulates Sp1 gene expression, reduced the promoter activity as well as endogenous MCAK levels. Exposure of HCT116 (p53+/+) cells to nutlin-3a, a validated activator of p53, caused a simultaneous reduction in Sp1 and MCAK protein levels, but not in HCT116 (p53-/-) cells. In contrast to wild-type (wt)-p53, tumor-derived p53 mutants (p53V143A, p53R248W, and p53R273H) failed to repress the Sp1-dependent activation of the MCAK promoter and to down-regulate endogenous levels of Sp1 and MCAK proteins. Collectively, these findings demonstrate that p53 can repress MCAK promoter activity indirectly via down-regulation of Sp1 expression level, and suggest that MCAK elevation in human tumor cells might be due to p53 mutation.