Targeted Knockdown of the Kinetochore Protein D40/Knl-1 Inhibits Human Cancer in a p53 Status-Independent Manner

Comprehensive molecular characterization of long-term glioblastoma survivors

Fewer than 5 % glioblastoma (GBM) patients survive over five years and are termed long-term survivors (LTS), yet their molecular background is unclear. The present cohort included 72 isocitrate dehydrogenase (IDH)-wildtype GBM patients, consisting of 35 LTS and 37 short-term survivors (STS), and we employed whole exome sequencing, RNA-seq and DNA methylation array to delineate this largest LTS cohort to date. Although LTS and STS demonstrated analogous clinical characters and classical GBM biomarkers, CASC5 (P = 0.002) and SPEN (P = 0.013) mutations were enriched in LTS, whereas gene-to-gene fusions were concentrated in STS (P = 0.007). Importantly, LTS exhibited higher tumor mutation burden (P < 0.001) and copy number (CN) increase (P = 0.013), but lower mutant-allele tumor heterogeneity score (P < 0.001) and CN decrease (P = 0.026). Additionally, LTS demonstrated hypermethylated genome (P < 0.001) relative to STS. Differentially expressed and methylated genes both enriched in olfactory transduction. Further, analysis of the tumor microenvironment revealed higher infiltration of M1 macrophages (P = 0.043), B cells (P = 0.016), class-switched memory B cells (P = 0.002), central memory CD4+ T cells (P = 0.031) and CD4+ Th1 cells (P = 0.005) in LTS. We also separately analyzed a subset of patients who were methylation class-defined GBM, contributing 70.8 % of the entire cohort, and obtained similar results relative to prior analyses. Finally, we demonstrated that LTS and STS could be distinguished using a subset of molecular features. Taken together, the present study delineated unique molecular attributes of LTS GBM.

Role of Kinetochore Scaffold 1 (KNL1) in Tumorigenesis and Tumor Immune Microenvironment in Pan-Cancer: Bioinformatics Analyses and Validation of Expression

Purpose

Kinetochore scaffold 1 (KNL1), a crucial protein during cell mitosis participating in cell division, was widely expressed in multiple kinds of cancers. However, the expression profile, the effect on cell biological function, tumor immune microenvironment, and predictive value of clinical prognosis in pan-cancer of KNL1 still require a comprehensive inquiry.

Methods

The mRNA and protein expression profile of KNL1 was validated in pan-cancer using different databases. Six algorithms were used to explore the correlation between KNL1 and immune infiltration and the relationship between KNL1 and tumor mutation burden (TMB), microsatellite instability (MSI), and TIDE score were calculated. The diagnostic and clinical prognostic predictive ability of KNL1 was assessed. Differentially expressed genes (DEGs) of KNL1 were screened out and function enrichment analyses were performed in pancreatic adenocarcinoma (PAAD), stomach adenocarcinoma (STAD), and bladder urothelial carcinoma (BLCA). Finally, 8 cases of pancreatic adenocarcinoma tissues and paired adjacent tissues were collected for immunohistochemical (IHC) staining and the histological score (H-score) was calculated. Real-time PCR was performed in gastric cancer and bladder cancer cell lines.

Results

KNL1 was abnormally upregulated in more than half of cancers across different databases. IHC and real-time PCR verified the up-regulated expression in cancer tissues in PAAD, gastric cancer, and BLCA. The satisfactory diagnostic value of KNL1 was indicated in 30 cancers and high KNL1 expression was associated with poorer overall survival (OS) in 12 cancers. The prognostic role of KNL1 as a predictive biomarker of PAAD was clarified. KNL1 played an active part in the cell cycle and cell proliferation. Moreover, KNL1 was likely to mold the Th2-dominant suppressive tumor immune microenvironment and was associated with TMB, MSI, and immune checkpoint-related genes in pan-cancer.

Conclusion

Our study elucidated the anomalous expression of KNL1 and revealed that KNL1 was a promising prognostic biomarker in pan-cancer.

KNL1 is a prognostic and diagnostic biomarker related to immune infiltration in patients with uterine corpus endometrial carcinoma

Background

The incidence and mortality of uterine corpus endometrial carcinoma (UCEC) are increasing yearly. There is currently no screening test for UCEC, and progress in its treatment is limited. It is important to identify new biomarkers for screening, diagnosing and predicting the outcomes of UCEC. A large number of previous studies have proven that KNL1 is crucial in the development of lung cancer, colorectal cancer and cervical cancer, but there is a lack of studies about the role of KNL1 in the development of UCEC.

Methods

The mRNA and protein expression data of KNL1 in The Cancer Genome Atlas (TCGA), Gene Expression Omnibus (GEO) and UALCAN databases and related clinical data were used to analyze the expression differences and clinical correlations of KNL1 in UCEC. A total of 108 clinical samples were collected, and the results of bioinformatics analysis were verified by immunohistochemistry. KNL1 and its related differentially expressed genes were used to draw a volcano map, construct a PPI protein interaction network, and perform gene ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), gene set enrichment analysis (GSEA) and immune infiltration analysis to predict the function of KNL1 during UCEC progression. The prognostic data of TCGA and 108 clinical patients were used to analyze the correlation of KNL1 expression with the survival of patients, and KM survival curves were drawn. The UCEC cell lines Ishikawa and Hec-1-A were used to verify the function of KNL1.

Results

KNL1 is significantly overexpressed in UCEC and is associated with a poor prognosis. KNL1 overexpression is closely related to cell mitosis, the cell cycle and other functions and is correlated with the International Federation of Gynecology and Obstetrics (FIGO) stage, histological grade and other characteristics of UCEC patients. Knockdown of KNL1 expression in UCEC cell lines can inhibit their proliferation, invasion, metastasis and other phenotypes.

Conclusion

KNL1 is a prognostic and diagnostic biomarker associated with immune evasion in patients with UCEC.

High expression of KNL1 in prostate adenocarcinoma is associated with poor prognosis and immune infiltration

Prostate adenocarcinoma (PRAD) is a common malignancy with increasing morbidity and mortality. Kinetochore scaffold 1 (KNL1) has been reported to be involved in tumor progression and prognosis in other tumors, but its role in PRAD has not been reported in detail. KNL1 expression analysis, clinicopathological parameters analysis, prognostic correlation analysis, molecular interaction network and functional abdominal muscle analysis and immune infiltration analysis by using multiple online databases and downloaded expression profile. The results suggest that KNL1 is highly expressed in PRAD, which is associated with worse prognosis in PRAD patients. KnL1-related genes are highly enriched in mitotic function, which is considered to be highly related to the development of cancer. Finally, KNL1 expression is associated with a variety of tumor infiltrating immune cells, especially Treg and Th2 cells. In conclusion, our findings provide preliminary evidence that KNL1 may be an independent prognostic predictor of PRAD and is associated with immune infiltration.

Silencing of KNTC1 inhibits hepatocellular carcinoma cells progression via suppressing PI3K/Akt pathway

Kinetochore associated 1 (KNTC1) encodes a kinetochore component in Rod-Zwilch-ZW10 (RZZ) complex which is essential for the segregation of sister chromatids during mitosis and participates in the spindle checkpoint. Recent research demonstrated that kinetochore proteins may be potential biomarkers and may contribute to the development of human malignancies. Our immunohistochemistry experiment showed that KNTC1 was highly expressed in hepatocellular carcinoma (HCC) tissues and correlated with terrible prognosis, indicating that KNTC1 acts a pivotal role in HCC development. Furthermore, lentivirus delivered short hairpin RNA (shRNA) KNTC1 (Lv-shKNTC1) was applied to infect BEL-7404 and SK-HEP-1 to identify roles of KNTC1 on HCC. Lv-shKNTC1 cells showed reduced proliferation ability, increased apoptosis and decreased migration ability. In vivo experiments suggested that xenografts grow significantly slower upon the silencing of KNTC1. Mechanistically, the protein levels of PIK3CA, p-Akt, CCND1, CDK6 are all down-regulated in Lv-KNTC1 cells and the Lv-shKNTC1 tumor tissues of nude mice. Therefore, KNTC1 may affect the biological activity of HCC cells through PI3K/Akt signaling pathway. Further studies revealed that ZW10 is a pivotal protein that participates in KNTC1-induced regulation of PI3K/Akt signaling pathway. In summary, the key finding of this report highlighted the significance of KNTC1 in tumor regression of HCC, demonstrating KNTC1 as an innovative target for adjuvant treatment of HCC.

CASC5 is a potential cancer-testis gene in human urinary bladder transitional cell carcinoma

Urinary Bladder cancer (UBC) is a diversified disease with an array of clinicopathological attributes. Several studies have shown that cancer susceptibility candidate 5 (CASC5) plays important roles in various types of malignancies; however its expression and clinical significance in human UBC remain largely unknown. This research study was intended to explore mRNA/protein expression pattern of CASC5 as a member of the cancer-testis (CT) gene family and assess its clinical utility in diagnostic management of patients with UBC. Quantitative real-time PCR (qRT-PCR) and immunohistochemistry (IHC) was employed to appraise the detailed expression profile of CASC5 in patients with UBC. The mRNA over expression of CASC5 was detected in testis tissue and relatively high frequency 59.2% (45 of 76) of CASC5 mRNA was detected in UBC tissues. CASC5 mRNA relative mean fold expression was also significantly (p < 0.01) higher in the muscle-invasive tumor tissues compared to non-muscle-invasive tumor tissues (12.26 ± 9.53 vs. 4.64 ± 2.50, p = 0.005). Heterogeneous staining pattern of CASC5 protein was exclusively detected using IHC. The frequency of CASC5 protein over expression was detected in 67.7% (44 of 65) UBC patients and negative in benign prostatic hyperplasia (BPH). Further, CASC5 protein expression was significantly (p < 0.001) associated with cigarette smoking habit in UBC patients. Our study findings testified that CASC5 over expression among patients with UBC as compared to controls and concludes that CASC5 is a potential CT gene in UBC.

Inhibiting microcephaly genes as alternative to microtubule targeting agents to treat brain tumors

Medulloblastoma (MB) and gliomas are the most frequent high-grade brain tumors (HGBT) in children and adulthood, respectively. The general treatment for these tumors consists in surgery, followed by radiotherapy and chemotherapy. Despite the improvement in patient survival, these therapies are only partially effective, and many patients still die. In the last decades, microtubules have emerged as interesting molecular targets for HGBT, as various microtubule targeting agents (MTAs) have been developed and tested pre-clinically and clinically with encouraging results. Nevertheless, these treatments produce relevant side effects since they target microtubules in normal as well as in cancerous cells. A possible strategy to overcome this toxicity could be to target proteins that control microtubule dynamics but are required by HGBT cells much more than in normal cell types. The genes mutated in primary hereditary microcephaly (MCPH) are ubiquitously expressed in proliferating cells, but under normal conditions are selectively required during brain development, in neural progenitors. There is evidence that MB and glioma cells share molecular profiles with progenitors of cerebellar granules and of cortical radial glia cells, in which MCPH gene functions are fundamental. Moreover, several studies indicate that MCPH genes are required for HGBT expansion. Among the 25 known MCPH genes, we focus this review on KNL1, ASPM, CENPE, CITK and KIF14, which have been found to control microtubule stability during cell division. We summarize the current knowledge about the molecular basis of their interaction with microtubules. Moreover, we will discuss data that suggest these genes are promising candidates as HGBT-specific targets.

CASC5 is a potential tumour driving gene in lung adenocarcinoma

Previous studies have shown that cancer susceptibility candidate 5 (CASC5) plays important roles in several types of cancer. But its expression and clinical significance in human pan-cancer remain largely unclear. In the present study, we comprehensively analysed the expression profile and prognostic values of CASC5 in pan-cancer across 33 cancer types based on the online TCGA analysis databases. CASC5 was found to be abnormally expressed in 16 types of cancer. In addition, dysregulated expression of CASC5 was closely associated with patient overall survival (OS) in kidney renal papillary cell carcinoma (KIRP), lung adenocarcinoma (LUAD), pancreatic adenocarcinoma (PAAD) and thymoma (THYM). By comparative analysis, we found that CASC5 was significantly up-regulated in LUAD and predicted poor patient OS. High CASC5 expression was closely correlated with tumour advanced stages of patients with LUAD. Through GSEA based on the KEGG database, CASC5 was found to be closely related to DNA replication and microRNA regulation in LUAD. Functionally, knockdown of CASC5 could inhibit cell proliferation of LUAD cells in vitro, rather than affecting cell migration and invasion. Mechanistically, CASC5 promoted proliferation of LUAD cells by targeting miR-139-5p. Collectively, our findings reveal that CASC5 is a novel oncogenic gene in LUAD and may be a potential clinical target and (or) biomarker for this human malignancy. SIGNIFICANCE OF THE STUDY: In this study, we for the first time comprehensively analysed the transcriptional level and prognostic significance of CASC5 in human pan-cancer across 33 cancer types using online TCGA databases. Our study indicates that CASC5 is aberrantly expressed in many tumours and is closely related to the patient overall survival of several tumour types. Our findings reveal that CASC5 is a novel oncogene in LUAD based on bioinformatic analysis and functional experiments. Mechanistically, CASC5 promoted LUAD proliferation by targeting miR-139-5p. Results of this study suggest that CASC5 is a potential clinical target and (or) biomarker for LUAD.

The Yin and Yang of Autosomal Recessive Primary Microcephaly Genes: Insights from Neurogenesis and Carcinogenesis

The stem cells of neurogenesis and carcinogenesis share many properties, including proliferative rate, an extensive replicative potential, the potential to generate different cell types of a given tissue, and an ability to independently migrate to a damaged area. This is also evidenced by the common molecular principles regulating key processes associated with cell division and apoptosis. Autosomal recessive primary microcephaly (MCPH) is a neurogenic mitotic disorder that is characterized by decreased brain size and mental retardation. Until now, a total of 25 genes have been identified that are known to be associated with MCPH. The inactivation (yin) of most MCPH genes leads to neurogenesis defects, while the upregulation (yang) of some MCPH genes is associated with different kinds of carcinogenesis. Here, we try to summarize the roles of MCPH genes in these two diseases and explore the underlying mechanisms, which will help us to explore new, attractive approaches to targeting tumor cells that are resistant to the current therapies.

Effect of KNL1 on the proliferation and apoptosis of colorectal cancer cells

Objective:

To identify the expression of kinetochore scaffold 1 (KNL1) in colorectal tumor tissues and to clarify the role of this gene in the proliferation capability of colorectal cancer cells.

Methods:

A total of 108 paired colorectal tumor and normal tissue samples were collected from patients with colorectal cancer and subjected to quantitative polymerase chain reaction and immunohistochemistry analyses. Expression levels of KNL1 mRNA and protein were compared between tumor and normal tissues, and KNL1 levels were evaluated in relation to the patients’ tumor differentiation, sex, lymph node metastasis, TNM stage, infiltration depth, age, and tumor location. Survival curves were also constructed and compared between patients with tumor samples with and without KLN1 protein expression. KNL1 was under-expressed in colorectal cancer cells in vitro using lentiviral transfection with short hairpin RNA, and its function was evaluated by proliferation, colony-formation, and apoptosis assays. Expression levels of BUB1 protein were also compared between tumor and normal tissues, and the correlation between KNL1 expression and BUB1 expression in colorectal cancer tissues was examined.

Results:

KNL1 mRNA and protein were both highly expressed in colorectal tumor tissues compared with paired normal tissues. KNL1 downregulation significantly inhibited colorectal cancer cell proliferation and colony formation, and promoted apoptosis. KNL1 protein expression was significantly associated with tumor differentiation, but not with sex, lymph node metastasis, TNM stage, infiltration depth, age, or tumor location. KNL1 protein expression was also significantly associated with poorer survival. Moreover, there was a significant correlation between KNL1 and BUB1 in colorectal cancer tissues.

Conclusions:

KNL1 plays an effective role in decreasing apoptosis and promoting the proliferation of colorectal cancer cells, suggesting that its inhibition may represent a promising therapeutic approach in patients with colorectal cancer.

LncRNAs-directed PTEN enzymatic switch governs epithelial-mesenchymal transition

Despite the structural conservation of PTEN with dual-specificity phosphatases, there have been no reports regarding the regulatory mechanisms that underlie this potential dual-phosphatase activity. Here, we report that K27-linked polyubiquitination of PTEN at lysines 66 and 80 switches its phosphoinositide/protein tyrosine phosphatase activity to protein serine/threonine phosphatase activity. Mechanistically, high glucose, TGF-β, CTGF, SHH, and IL-6 induce the expression of a long non-coding RNA, GAEA (Glucose Aroused for EMT Activation), which associates with an RNA-binding E3 ligase, MEX3C, and enhances its enzymatic activity, leading to the K27-linked polyubiquitination of PTEN. The MEX3C-catalyzed PTENK27-polyUb activates its protein serine/threonine phosphatase activity and inhibits its phosphatidylinositol/protein tyrosine phosphatase activity. With this altered enzymatic activity, PTENK27-polyUb dephosphorylates the phosphoserine/threonine residues of TWIST1, SNAI1, and YAP1, leading to accumulation of these master regulators of EMT. Animals with genetic inhibition of PTENK27-polyUb, by a single nucleotide mutation generated using CRISPR/Cas9 (PtenK80R/K80R), exhibit inhibition of EMT markers during mammary gland morphogenesis in pregnancy/lactation and during cutaneous wound healing processes. Our findings illustrate an unexpected paradigm in which the lncRNA-dependent switch in PTEN protein serine/threonine phosphatase activity is important for physiological homeostasis and disease development.

shRNA‑mediated knockdown of KNTC1 suppresses cell viability and induces apoptosis in esophageal squamous cell carcinoma

Kinetochore‑associated proteins are critical components of mitotic checkpoints, which are essential for faithful chromosomal segregation and spindle assembly during cell division. Recent advances have demonstrated that kinetochore‑associated proteins are upregulated and serve significant roles in the carcinogenesis of numerous types of cancer. However, the effects of kinetochore‑associated protein 1 (KNTC1) on human cancer, particularly on esophageal squamous cell carcinoma (ESCC), remain unclear. The present study revealed that KNTC1 was highly expressed in ESCC cell lines. Subsequently, lentivirus‑mediated short hairpin RNAs were used to knockdown KNTC1 expression in human ESCC cell lines. Cell growth and viability were measured using multiparametric high‑content screening and the MTT assay, respectively. Cell apoptosis was assessed by staining cells with Annexin V‑allophycocyanin and was detected using FACScan flow cytometry. The results demonstrated that knockdown of KNTC1 effectively inhibited cell viability and increased apoptosis. In addition, a gene set enrichment analysis of online ESCC datasets indicated that KNTC1 overexpression was associated with increases in the mitotic spindle and hypoxia pathways, and decreases in the DNA repair and mismatch repair pathways. The findings of the present study suggested that KNTC1 may have an essential role in mediating cell viability and apoptosis in human ESCC cells and may serve as a novel therapeutic target for ESCC.

Expression-based analyses indicate a central role for hypoxia in driving tumor plasticity through microenvironment remodeling and chromosomal instability

Can transcriptomic alterations drive the evolution of tumors? We asked if changes in gene expression found in all patients arise earlier in tumor development and can be relevant to tumor progression. Our analyses of non-mutated genes from the non-amplified regions of the genome of 158 triple-negative breast cancer (TNBC) cases identified 219 exclusively expression-altered (EEA) genes that may play important role in TNBC. Phylogenetic analyses of these genes predict a "punctuated burst" of multiple gene upregulation events occurring at early stages of tumor development, followed by minimal subsequent changes later in tumor progression. Remarkably, this punctuated burst of expressional changes is instigated by hypoxia-related molecular events, predominantly in two groups of genes that control chromosomal instability (CIN) and those that remodel tumor microenvironment (TME). We conclude that alterations in the transcriptome are not stochastic and that early-stage hypoxia induces CIN and TME remodeling to permit further tumor evolution.

D40/KNL1/CASC5 and autosomal recessive primary microcephaly

Autosomal recessive primary microcephaly (MCPH) is a very rare neuro-developmental disease with brain size reduction. More than a dozen loci encoding proteins of diverse function have been shown to be responsible for MCPH1-13. Mutations in the D40/KNL1/CASC5 gene, which was initially characterized as a gene involved in chromosomal translocation in leukemia and as a member of the cancer/testis gene family, was later found to encode a kinetochore protein essential for mitotic cell division and to cause MCPH4. Although our previous studies showed that this gene is required for cell growth and division in vitro and in animal experiments, the revelation that mutations in this gene caused microcephaly provides in vivo evidence of a critical role in brain growth. In this review, we describe mutated gene targets responsible for MCPH1-13 and summarize clinical studies of, and molecular and biological aspects of the gene and encoded protein responsible for MCPH4.

Targeting mitotic pathways for endocrine-related cancer therapeutics

A colossal amount of basic research over the past few decades has provided unprecedented insights into the highly complex process of cell division. There is an ever-expanding catalog of proteins that orchestrate, participate and coordinate in the exquisite processes of spindle formation, chromosome dynamics and the formation and regulation of kinetochore microtubule attachments. Use of classical microtubule poisons has still been widely and often successfully used to combat a variety of cancers, but their non-selective interference in other crucial physiologic processes necessitate the identification of novel druggable components specific to the cell cycle/division pathway. Considering cell cycle deregulation, unscheduled proliferation, genomic instability and chromosomal instability as a hallmark of tumor cells, there lies an enormous untapped terrain that needs to be unearthed before a drug can pave its way from bench to bedside. This review attempts to systematically summarize the advances made in this context so far with an emphasis on endocrine-related cancers and the avenues for future progress to target mitotic mechanisms in an effort to combat these dreadful cancers.