CDCA8, a mitosis-related gene, as a prospective pan-cancer biomarker: implications for survival prognosis and oncogenic immunology.

BACKGROUND: Human cell division cycle-associated protein 8 (CDCA8), a critical regulator of mitosis, has been identified as a prospective prognostic biomarker in several cancer types, including breast, colon, and lung cancers. This study analyzed the diagnostic/prognostic potential and clinical implications of CDCA8 across diverse cancers. METHODS: Bioinformatics and molecular experiments. RESULTS: Analyzing TCGA data via TIMER2 and GEPIA2 databases revealed significant up-regulation of CDCA8 in 23 cancer types compared to normal tissues. Prognostically, elevated CDCA8 expression correlated with poorer overall survival in KIRC, LUAD, and SKCM, emphasizing its potential as a prognostic marker. UALCAN analysis demonstrated CDCA8 up-regulation based on clinical variables, such as cancer stage, race, and gender, in these cancers. Epigenetic exploration indicated reduced CDCA8 promoter methylation levels in Kidney Renal Clear Cell Carcinoma (KIRC), Lung Adenocarcinoma (LUAD), and Skin Cutaneous Melanoma (SKCM) tissues compared to normal controls. Promoter methylation and mutational analyses showcased a hypomethylation and low mutation rate for CDCA8 in these cancers. Correlation analysis revealed positive associations between CDCA8 expression and infiltrating immune cells, particularly CD8+ and CD4+ T cells. Protein-protein interaction (PPI) network analysis unveiled key interacting proteins, while gene enrichment analysis highlighted their involvement in crucial cellular processes and pathways. Additionally, exploration of CDCA8-associated drugs through DrugBank presented potential therapeutic options for KIRC, LUAD, and SKCM. In vitro validation using reverse transcription-quantitative polymerase chain reaction (RT-qPCR) confirmed elevated CDCA8 expression in LUAD cell lines (A549 and H1299) compared to control cell lines (Beas-2B and NL-20). CONCLUSION: This study provides concise insights into CDCA8's multifaceted role in KIRC, LUAD, and SKCM, covering expression patterns, diagnostic and prognostic relevance, epigenetic regulation, mutational landscape, immune infiltration, and therapeutic implications.

CDCA8 Facilitates Tumor Proliferation and Predicts a Poor Prognosis in Hepatocellular Carcinoma.

CDCA8 expression is abnormally high in a variety of cancers and involved in the biological process of tumor malignancy. In this study, we discovered that the expression of CDCA8 was up-regulated in hepatocellular carcinoma cancer (HCC) tissues and high levels of CDCA8 are associated with larger tumor size, higher AFP (α-fetoprotein) levels, and unfavorable prognosis. Cell functional experiments revealed that CDCA8 silencing remarkably inhibited proliferation and promoted apoptosis in SNU-387 and Hep-3B cells. The results of flow cytometry showed that CDCA8 regulated CDK1 and cyclin B1 expression to arrest at the S phase, inhibited proliferation, and promoted apoptosis. In addition, in vivo studies have confirmed that silencing CDCA8 could regulate CDK1/cyclin B1 signaling axis to inhibit the growth of HCC xenograft tumor. Our study demonstrated CDCA8 acts an oncogene to facilitate cell proliferation of HCC via regulating cell cycle, indicating the promising application value of CDCA8 for HCC diagnosis and clinical treatment.

Cell division cycle-associated 8 is a prognostic biomarker related to immune invasion in hepatocellular carcinoma.

BACKGROUND: Cell division cycle-associated 8 (CDCA8) is involved in numerous signaling networks, and it serves a crucial modulatory function in multiple malignant tumors. However, its significance in prognosis and immune infiltration in hepatocellular carcinoma (HCC) remains unclear. MATERIALS AND METHODS: Herein, we examined the CDCA8 levels in tumor tissues, as well as its associated signaling pathways and correlation with immune infiltration. Additionally, we further clarified the prognostic significance of CDCA8 among HCC patients. HCC patient information was recruited from The Cancer Genome Atlas (TCGA). Using bioinformatics, the following parameters were analyzed among HCC patients: CDCA8 expression, enrichment analysis, immune infiltration, and prognosis analysis. Moreover, we employed in vitro investigations, such as, qRT-PCR, immunohistochemistry (IHC), and cell functional experiments to validate our results. RESULTS: Elevated CDCA8 expression in HCC patients was markedly associated with T stage, pathological status (PS), tumor status (TS), histologic grade (HG), and AFP. Elevated CDCA8 expression HCC patients exhibited reduced overall survival (OS) (p < 0.001), disease-specific survival (DSS) (p < 0.001), and progress free interval (PFI) H(p < 0.001). According to the ROC analysis, the area under the curve (AUC) was 0.997. Multivariate analysis revealed that CDCA8 was a stand-alone prognostic indicator of patient OS (p = 0.009) and DSS (p = 0.006). A nomogram was then generated based on the multivariate analysis, and the C-indexes and calibration chart revealed excellent predictive performance in determining HCC patient outcome. Based on the GSEA analysis, CDCA8 modulated the P53, Notch, PPAR, E2F networks. We observed a direct link between CDCA8 levels and Th2 and T helper cells, and a negative link between CDCA8 levels and dendritic cells (DC), neutrophils, cytotoxic cells, and CD8 T cells. Furthermore, CDCA8 deficiency inhibited liver cancer cell proliferation and invasion. CONCLUSION: In conclusion, these findings indicate that CDCA8 is a new molecular bioindicator of HCC patient prognosis, and it is an excellent candidate for therapeutic target against HCC.

TMED3 promotes the development of malignant melanoma by targeting CDCA8 and regulating PI3K/Akt pathway.

BACKGROUND: Transmembrane emp24 domain containing (TMED) proteins are known to play pivotal roles in normal development, but have been reported to be implicated in pancreatic disease, immune system disorders, and cancers. As far as TMED3 is concerned, its roles in cancers are controversial. However, evidence describing TMED3 in the context of malignant melanoma (MM) is scarce. RESULTS: In this study, we characterized the functional significance of TMED3 in MM and identified TMED3 as a tumor-promoting factor in MM development. Depletion of TMED3 arrested the development of MM in vitro and in vivo. Mechanistically, we found that TMED3 could interact with Cell division cycle associated 8 (CDCA8). Knocking down CDCA8 suppressed cell events associated with MM development. On the contrary, elevating CDCA8 augmented cell viability and motility and even reversed the inhibitory effects of TMED3 knockdown on MM development. On the other hand, we found that the levels of P-Akt and P-PI3K were decreased in response to TMED3 downregulation, which was partially abolished following SC79 treatment. Thus, our suspicion was that TMED3 exacerbates MM progression via PI3K/Akt pathway. More notably, previously decreased P-Akt and P-PI3K in TMED3-depleted cells were rescued after overexpressing CDCA8. Also, previously impaired cell events due to CDCA8 depletion were ameliorated after SC79 addition, implying that TMED3 regulates PI3K-AKT pathway via CDCA8, thereby promoting MM development. CONCLUSIONS: Collectively, this study established the link between TMED3 and MM, and provides a potential therapeutic intervention for patients with MM harboring abundant TMED3.

A 1-kb human CDCA8 promoter directs the spermatogonia-specific luciferase expression in adult testis.

Cell division cycle associated 8 (CDCA8) is a component of the chromosomal passenger complex and plays an essential role in mitosis, meiosis, cancer growth, and undifferentiated state of embryonic stem cells. However, its expression and role in adult tissues remain largely uncharacterized. Here, we studied the CDCA8 transcription in adult tissues by generating a transgenic mouse model, in which the luciferase was driven by a 1-kb human CDCA8 promoter. Our previous study showed that this 1-kb promoter was active enough to dictate reporter expression faithfully reflecting endogenous CDCA8 expression. Two founder mice carrying the transgene were identified. In vivo imaging and luciferase assays in tissue lysates revealed that CDCA8 promoter was highly activated and drove robust luciferase expression in testes. Subsequently, immunohistochemical and immunofluorescent staining showed that in adult transgenic testes, the expression of luciferase was restricted to a subset of spermatogonia that were located along the basement membrane and positive for the expression of GFRA1, a consensus marker for early undifferentiated spermatogonia. These findings for the first time indicate that the CDCA8 was transcriptionally activated in testis and thus may play a role in adult spermatogenesis. Moreover, the 1-kb CDCA8 promoter could be used for spermatogonia-specific gene expression in vivo and the transgenic lines constructed here could also be used for recovery of spermatogonia from adult testes.

Let-7c-5p down-regulates immune-related CDCA8 to inhibit hepatocellular carcinoma.

OBJECTIVE: The aim of this study is to investigate the effect of let-7c-5p on the malignant behaviors of hepatocellular carcinoma (HCC) and its specific molecular pathway. METHODS: Differential expression and survival analysis of let-7c-5p were obtained from The Cancer Genome Atlas database, and then its expression level was preliminarily verified through qPCR. The effect of let-7c-5p on the malignant phenotype of HCC cells was subsequently evaluated using CCK-8, transwell, wound healing, and flow cytometry assays. Downstream mRNA regulated by let-7c-5p was identified and confirmed by ENCORI database, dual-luciferase reporter, and western blot assays. The immunocorrelation of genes was evaluated by Xiantao tool, and TIMER and TISIDB databases. RESULTS: The expression level of let-7c-5p in HCC was obviously reduced, which was found to be closely associated with the short survival time of HCC patients. Cell phenotypic experiments showed that let-7c-5p inhibited proliferation, invasion, and migration and promoted apoptosis of HCC cells. Dual-luciferase reporter and western blot analysis demonstrated that CDCA8 is a downstream mRNA of let-7c-5p and is negatively regulated by it. Rescue experiment revealed that CDCA8 reversed the effect of let-7c-5p on the malignant phenotype of HCC cells. Furthermore, analysis of the public database revealed that CDCA8 is related to some immune cells and immunomodulators, and that it may participate in the regulation of some immune pathways and immune functions. CONCLUSION: Let-7c-5p has been proved to suppress HCC by down-regulating immune-related CDCA8, which will help understand the pathogenesis of HCC and develop drugs for its treatment.

CDCA8/SNAI2 Complex Activates CD44 to Promote Proliferation and Invasion of Pancreatic Ductal Adenocarcinoma.

(1) Background: Recently, cell division cycle associated 8 (CDCA8) was found to be overexpressed in pancreatic ductal adenocarcinoma (PDAC). Here, we aimed to explore the specific mechanism of action of CDCA8 in PDAC progression. (2) Methods: All human PDAC samples and clinical data were collected from Huashan Hospital, Fudan University. All experimental studies were carried out using many in vitro and in vivo assays, including lentiviral transfection, real-time quantitative polymerase chain reaction (qPCR), western blotting, co-immunoprecipitation (Co-IP), chromatin IP (ChIP)-qPCR, dual-luciferase reporter, and in vivo imaging assays. (3) Results: Clinical data analysis of human PDAC samples revealed that CDCA8 overexpression were positively and negatively associated with tumor grade (p = 0.007) and overall survival (p = 0.045), respectively. CDCA8 knockdown inhibited PDAC proliferation and invasion in in vitro and in vivo assays. CD44 was also up-regulated by CDCA8 during PDAC progression. CDCA8 could be combined with SNAI2 to form a CDCA8/SNAI2 complex to integrate with the CD44 promoter as indicated through ChIP-qPCR and dual-luciferase reporter assays. (4) Conclusion: We showed that CDCA8-CD44 axis plays a key role in the proliferation and invasion of PDAC, which provides a potential target for treatment.

Long noncoding RNA-LINC00478 promotes the progression of clear cell renal cell carcinoma through PBX3.

Long noncoding RNAs play an important regulatory role in the development and progression of tumors. Our study found that LINC00478 was upregulated in clear cell renal cell carcinoma (ccRCC), so we made an in-depth exploration into its mechanism. In Caki-2 cells, we established the oe-LINC00478 cell line overexpressing LINC00478, and established underexpressing sh-LINC00478 cell line by short hairpin RNA silencing. The abilities of oe-LINC00478 cell invasion and metastasis were significantly enhanced, and the cell proliferative potential was also improved. The cellular expressions of PBX3, CDCA8, and CDK2 were upregulated, while in the sh-LINC00478 cells, the proliferative potential and metastatic and invasive abilities were weakened. Similarly, we established the PBX3-overexpressing oe-PBX3 cell line and the PBX3-underexpressing sh-PBX3 cell line, finding that the PBX3 overexpression enhanced the metastatic and invasive abilities of Caki-2 cells. When we overexpressed LINC00478 in PBX3-knockout Caki-2-PBX3- / - cells, no significant changes were noted in the metastatic or invasive ability. Through RNA pull-down and RNA-binding protein immunoprecipitation assays, we found that LINC00478 could facilitate the transcription-translation processes of PBX3 by binding to it, thus further promoting the expression of downstream cyclins to exert its action. In animal experimentation, the oe-LINC00478 and sh-LINC00478 Caki-2 cells were separately seeded, revealing that the tumor volume was significantly larger in the oe-LINC00478 group than in the sh-LINC00478 group. This study finds that by promoting the PBX3 transcription, LINC00478 can further regulate the expressions of downstream cyclins, thereby facilitating the metastasis and invasion of ccRCC.

CDCA8 Contributes to the Development and Progression of Thyroid Cancer through Regulating CDK1.

Background: This study aims to reveal regulatory role of cell division cycle associated 8 (CDCA8) in thyroid cancer progression and metastasis. Methods: A series of experiments in vivo and in vitro were performed to explore the function of CDCA8 in thyroid cancer. Results: Immunohistochemical analysis showed that CDCA8 expression levels were upregulated in thyroid cancer tissues compared with normal tissues, and were statistically correlated with tumor stage. Results of in vitro loss-of-function assay showed that downregulation of endogenous expression of CDCA8 could significantly inhibit cell proliferation, colony formation, cell migration, and promote apoptosis. Thyroid cancer cells lacking CDCA8 expression also had reduced tumorigenicity in vivo. Further, results of preliminary mechanistic exploration showed that CDK1 may be a potential downstream molecule of CDCA8 in regulating thyroid cancer progression. We subsequently confirmed that CDK1 itself exerted a significant regulatory function in thyroid cancer by loss- and gain-of-function experiments. Moreover, overexpression of CDK1 could weaken the tumor suppressive effect caused by CDCA8 knockdown. Conclusions: CDCA8 functions as an oncogene in thyroid cancer, and CDCA8 knockdown suppresses cancer development in vitro and in vivo. Additionally, CDK1 was further identified as a potential target of CDCA8 in thyroid cancer.

Overexpression of CDCA8 Predicts Poor Prognosis and Promotes Tumor Cell Growth in Prostate Cancer.

Human cell division cycle-related protein 8 (CDCA8) is an essential component of the vertebrate chromosomal passenger complex (CPC). CDCA8 was confirmed to play a role in promoting malignant tumor progression. However, the exact function of CDCA8 in the development and progression of prostate cancer (PCa) remains unclear. In this study, the database GSE69223 was downloaded by the gene expression omnibus (GEO) database, as well as CDCA8 expression differences in multiple tumor tissues and normal tissues were detected by The Cancer Genome Atlas (TCGA), TIMER, Oncomine, and Ualcan databases. Kaplan-Meier and Cox regression methods were used to analyze the correlation between CDCA8 expression and prognosis in PCa. We confirmed the expression of CDCA8 in PCa tissues by HPA. We also analyzed the association of CDCA8 expression with PCa clinical characteristics in the TCGA database. To further understand the role of CDCA8 in PCa, we assessed the effects of CDCA8 on PCa cell growth, proliferation, and migration in vitro studies. As a result, CDCA8 was significantly overexpressed in PCa cells compared with normal prostate cells. High CDCA8 expression predicts poor prognosis in PCa patients, and CDCA8 expression was higher in high-grade PCa. In addition, silencing of CDCA8 significantly inhibited PCa cell proliferation and migration. In summary, CDCA8 promoted the proliferation and migration of PCa cells.

Identification of UAP1L1 as a critical factor for prostate cancer and underlying molecular mechanism in tumorigenicity.

BACKGROUND: Prostate cancer is the second most common cancer in men, and some new target genes are needed to predict the risk of prostate cancer progression and the treatment. METHODS: In this study, the effects of UAP1L1 (UAP1-like-1) on prostate cancer were investigated by detecting the proliferation, migration, invasion and apoptosis of prostate cancer cells in vitro using MTT, wound healing, Transwell and flow cytometry assay, and the tumor growth in vivo. The downstream genes and pathways of UAP1L1 were explored using Ingenuity Pathway Analysis (IPA), and screened by qRT-PCR and western blot. The effects of CDCA8 on prostate cancer cells were also verified in vitro, which was through detecting the change of proliferation, migration, invasion and apoptosis of prostate cancer cells after CDCA8 knockdown. RESULTS: The results indicated that UAP1L1 promoted the proliferation, migration and invasion of prostate cancer cells, which was inhibited by downregulating CDCA8. Furthermore, the promotion of CDCA8 knockdown on cell apoptosis was reduced when UAP1L1 was simultaneously overexpressed. CONCLUSIONS: In conclusion, the results in this study revealed that UAP1L1 promoted the progression of prostate cancer through the downstream gene CDCA8.

MiR-133a-3p inhibits the malignant progression of oesophageal cancer by targeting CDCA8.

The study aims to explore the interaction between miR-133a-3p and cell division cycle associated 8 (CDCA8) in oesophageal cancer (EC) and their effect on malignant behaviour of EC cells. Differential miRNAs and mRNAs were obtained from The Cancer Genome Atlas (TCGA) database. Quantitative real-time PCR (qRT-PCR) was used to detect the expression levels of miR-133a-3p and CDCA8 mRNA in EC cells. Western blot was used to detect the expression of CDCA8 protein. CCK-8, flow cytometry and Transwell assays were conducted to detect cell proliferation, cell cycle and apoptosis, as well as migration and invasion, respectively. The targeting relationship between miR-133a-3p and CDCA8 was verified by dual-luciferase reporter gene assay. In EC, miR-133a-3p expression was evidently low and CDCA8 expression was prominently high. MiR-133a-3p downregulated CDCA8 expression. A range of cell function experiments revealed that CDCA8 promoted the proliferation, migration and invasion of EC cells, reduced cell cycle arrest in G0/G1 phase and inhibited cell apoptosis, while miR-133a-3p could reverse the above effects by regulating CDCA8. MiR-133a-3p is a crucial tumour suppressor miRNA in EC, playing a tumour suppressor role by targeting CDCA8.

Cell division cycle associated 8: A novel diagnostic and prognostic biomarker for hepatocellular carcinoma.

The cell division cycle associated 8 (CDCA8) is a crucial component of the chromosome passenger complex (CPC). It has been implicated in the regulation of cell dynamic localization during mitosis. However, its role in hepatocellular carcinoma (HCC) is not clearly known. In this study, data of 374 patients with HCC were retrieved from the Cancer Genome Atlas (TCGA) database. Pan analysis of Gene Expression Profiling Interactive Analysis (GEPIA) database was performed to profile the mRNA expression of CDCA8 in HCC. Then, the Kaplan-Meier plotter database was analysed to determine the prognostic value of CDCA8 in HCC. In addition, samples of tumour and adjacent normal tissues were collected from 88 HCC patients to perform immunohistochemistry (IHC), reverse transcription-quantitative polymerase chain reaction (qRT-PCR) and Western blotting. The results obtained from bioinformatic analyses were validated through CCK-8 assay, EdU assay, colony formation assay, cell cycle assays and Western blotting experiments. Analysis of the Kaplan-Meier plotter database showed that high expression of CDCA8 may lead to poor overall survival (OS, p = 4.06e-05) in patients with HCC. For the 88 patients with HCC, we found that stages and grades appeared to be strongly linked with CDCA8 expression. Furthermore, the high expression of CDCA8 was found to be correlated with poor OS (p = 0.0054) and progression-free survival (PFS, p = 0.0009). In vitro experiments revealed that inhibition of CDCA8 slowed cell proliferation and blocked the cell cycle at the G0/G1 phase. In vivo experiments demonstrated that inhibition of CDCA8 inhibited tumour growth. Finally, blockade of CDCA8 reduced the expression levels of cyclin A2, cyclin D1, CDK4, CDK6, Ki67 and PCNA. And, there is an interaction between CDCA8 and E2F1. In conclusion, this research demonstrates that CDCA8 may serve as a biomarker for early diagnosis and prognosis prediction of HCC patients. In addition, CDCA8 could be an effective therapeutic target in HCC.

miR-133b inhibits cell proliferation, migration, and invasion of lung adenocarcinoma by targeting CDCA8.

OBJECTIVE: Lung adenocarcinoma (LUAD) is the most common type of lung cancer. This study aims to explore the mechanism by which CDCA8 regulates cell proliferation, invasion, and migration of LUAD, and to generate novel insights into targeted therapy of LUAD. METHODS: Expression profiles of mature microRNAs (miRNAs) and mRNAs, along with clinical data of LUAD were downloaded from TCGA database for differential analysis and survival analysis to mine differentially expressed mRNAs. qRT-PCR was used to detect the expression of CDCA8 and miR-133b in LUAD cell lines, and western blot was used to detect protein expression. The effects of CDCA8 on the proliferation, migration, and invasion of LUAD cells were detected by CCK-8 assay, scratch healing assay, and Transwell assay. Bioinformatics predicted the target miRNA of CDCA8, and dual-luciferase reporter gene assay was used to verify the binding relationship between miR-133b and CDCA8. RESULTS: Data from TCGA-LUAD showed that CDCA8 was significantly overexpressed in LUAD tissue, while its upstream miRNA (miR-133b) was significantly lowly expressed. The result of dual-luciferase test showed that miR-133b targeted CDCA8. The results of in vitro functional experiments showed that overexpression of CDCA8 could promote the proliferation, invasion, and migration of LUAD cells, and miR-133b could reverse this promotion by targeting CDCA8. CONCLUSION: This study found that CDCA8 was a carcinogenic factor in LUAD cells and it was regulated by upstream miR-133b. miR-133b could inhibit proliferation, invasion, and migration of LUAD cells by targeting CDCA8.

Silencing CDCA8 Suppresses Hepatocellular Carcinoma Growth and Stemness via Restoration of ATF3 Tumor Suppressor and Inactivation of AKT/ß-Catenin Signaling.

Big data analysis has revealed the upregulation of cell division cycle associated 8 (CDCA8) in human hepatocellular carcinoma (HCC) and its poorer survival outcome. However, the functions of CDCA8 during HCC development remain unknown. Here, we demonstrate in vitro that CDCA8 silencing inhibits HCC cell growth and long-term colony formation and migration through the accumulation of the G2/M phase cell population. Conversely, CDCA8 overexpression increases the ability to undergo long-term colony formation and migration. RNA sequencing and bioinformatic analysis revealed that CDCA8 knockdown led to the same directional regulation in 50 genes (25 down- and 25 upregulated). It was affirmed based on protein levels that CDCA8 silencing downregulates the levels of cyclin B1 and p-cdc2 and explains how it could induce G2/M arrest. The same condition increased the protein levels of tumor-suppressive ATF3 and GADD34 and inactivated AKT/ß-catenin signaling, which plays an important role in cell growth and stemness, reflecting a reduction in sphere-forming capacity. Importantly, it was demonstrated that the extent of CDCA8 expression is much greater in CD133+ cancer stem cells than in CD133- cancer cells, and that CDCA8 knockdown decreases levels of CD133, p-Akt and ß-catenin and increases levels of ATF3 and GADD34 in the CD133+ cancer stem cell (CSC) population. These molecular changes led to the inhibition of cell growth and sphere formation in the CD133+ cell population. Targeting CDCA8 also effectively suppressed tumor growth in a murine xenograft model, showing consistent molecular alterations in tumors injected with CDCA8siRNA. Taken together, these findings indicate that silencing CDCA8 suppresses HCC growth and stemness via restoring the ATF3 tumor suppressor and inactivating oncogenic AKT/ß-catenin signaling, and that targeting CDCA8 may be the next molecular strategy for both primary HCC treatment and the prevention of metastasis or recurrence.

CDCA8 as an independent predictor for a poor prognosis in liver cancer.

BACKGROUND: Human cell division cycle associated 8 (CDCA8) a key regulator of mitosis, has been described as a potential prognostic biomarker for a variety of cancers, such as breast, colon and lung cancers. We aimed to evaluate the potential role of CDCA8 expression in the prognosis of liver cancer by analysing data from The Cancer Genome Atlas (TCGA). METHODS: The Wilcoxon rank-sum test was used to compare the difference in CDCA8 expression between liver cancer tissues and matched normal tissues. Then, we applied logistic regression and the Wilcoxon rank-sum test to identify the association between CDCA8 expression and clinicopathologic characteristics. Cox regression and the Kaplan-Meier method were used to examine the clinicopathologic features correlated with overall survival (OS) in patients from the TCGA. Gene set enrichment analysis (GSEA) was performed to explore possible mechanisms of CDCA8 according to the TCGA dataset. RESULTS: CDCA8 expression was higher in liver cancer tissues than in matched normal tissues. Logistic regression and the Wilcoxon rank-sum test revealed that the increased level of CDCA8 expression in liver cancer tissues was notably related to T stage (OR = 1.64 for T1/2 vs. T3/4), clinical stage (OR = 1.66 for I/II vs. III/IV), histologic grade (OR = 6.71 for G1 vs. G4) and histological type (OR = 0.24 for cholangiocarcinoma [CHOL] vs. hepatocellular carcinoma [LIHC]) (all P-values < 0.05). Kaplan-Meier survival analysis indicated that high CDCA8 expression was related to a poor prognosis in liver cancer (P = 2.456 × 10-6). Univariate analysis showed that high CDCA8 expression was associated with poor OS in liver cancer patients, with a hazard ratio (HR) of 1.85 (95% confidence interval [CI]: 1.47-2.32; P = 1.16 × 10-7). Multivariate analysis showed that CDCA8 expression was independently correlated with OS (HR = 1.74; CI: 1.25-12.64; P = 1.27 × 10-5). GSEA revealed that the apoptosis, cell cycle, ErbB, MAPK, mTOR, Notch, p53 and TGF-ß signaling pathways were differentially enriched in the CDCA8 high expression phenotype. CONCLUSIONS: High CDCA8 expression is a potential molecular predictor of a poor prognosis in liver cancer.

CDCA8, targeted by MYBL2, promotes malignant progression and olaparib insensitivity in ovarian cancer.

Ovarian cancer is the most lethal gynecologic malignancy. Poly (ADP-ribose) polymerase inhibitors (PARPi) are effective in treating ovarian cancer. However, cancer cell insensitivity and resistance remain challenges. Determination of the exact chemoresistance mechanisms and potential targeted therapies is urgent. CDCA8 (cell division cycle associated 8) participates in the tumorigenesis of various cancers; however, the exact biological function of CDCA8 in ovarian cancer remains obscure. Here, we found that CDCA8 was overexpressed in ovarian cancer and that high expression of CDCA8 promoted the proliferation of ovarian cancer cells in vitro and in vivo. Moreover, silencing of CDCA8 sensitized ovarian cancer cells to olaparib and cisplatin by inducing G2/M arrest, accelerating apoptosis, increasing DNA damage and interfering with RAD51 accumulation in vitro. In addition, MYBL2 (MYB proto-oncogene-like 2), identified as an upstream transcription factor of CDCA8, was positively correlated with the expression level of CDCA8 in ovarian cancer. Finally, MYBL2 enhanced the aggressive characteristics of ovarian cancer cells by regulating CDCA8. In conclusion, high CDCA8 expression was involved in the tumorigenesis, aggressiveness and chemoresistance of ovarian cancer. CDCA8 silencing combined with olaparib treatment might lead to substantial progress in ovarian cancer targeted therapy.

CDCA8 regulates meiotic spindle assembly and chromosome segregation during human oocyte meiosis.

As a member of the chromosomal passenger complex, CDCA8 (cell division cycle associated 8) plays an important role in human mitosis, but its roles in human meiosis are unknown. Here, we show that CDCA8 expression is increased and its encoded protein has dynamic localization in human oocytes from germinal vesicle breakdown (GVBD) to metaphase Ⅱ (MⅡ), and that there are multipolar spindles, disordered chromosomes, and that microtubule assembly is affected after CDCA8 RNA interference (RNAi) in GV-stage oocytes. The GVBD and polar body extrusion (PBE) rates were not affected following CDCA8 depletion, but the PBE time was extended. There was no statistical difference between CDCA8 expression of oocytes from older and younger women, but the first polar body from older women was prone to chromosome abnormalities, and oocytes with such abnormalities had lower CDCA8 expression than oocytes with normal polar bodies. These results indicate that CDCA8 is associated with bipolar spindle formation, chromosome segregation, PBE during human oocyte meiosis, and that it may affect the incidence of aneuploidy embryos in older women.

KIF18B promotes the proliferation of pancreatic ductal adenocarcinoma via activating the expression of CDCA8.

Pancreatic cancer is one of the malignant tumors with the worst prognosis, and the 5-year survival rate of this disease is less than 1%. About 90% of pancreatic cancer is pancreatic ductal adenocarcinoma (PDAC), and targeting therapy has become a promising treatment for PDAC in recent years. To improve the survival rate, novel therapeutic targets for PDAC are still urgently needed. KIF18B was initially identified as a member of the kinesin family and involved in multiple cellular processes, such as separation of chromosomes in mitosis. Recently, it was found that KIF18B was involved in the growth and development of multiple cancers. However, the potential link between KIF18B and PDAC is still unclear. In this study, we demonstrated that KIF18B was highly expressed in human PDAC tissues, and related with the poor prognosis and clinical features, such as tumor size (*p = .013) and pTNM stage (*p = .025), of patients with PDAC. We further found that KIF18B knockdown blocked the cell proliferation of PDAC in vitro and in vivo, and the cell cycle was arrested caused by KIF18B depletion. Additionally, we also found that KIF18B bound to the promoter region of the cell division cycle associated 8 and thus activated its transcription. Taken together, this study explored the molecular mechanism underlying KIF18B promoting PDAC and provided a novel therapeutic target of this disease.