Cep55/c10orf3, a tumor antigen derived from a centrosome residing protein in breast carcinoma. J Immunother. 2009;32:474-485. [PMID: 19609239 DOI: 10.1097/CJI.0b013e3181a1d109]

N6-methyladenosine-mediated LINC01087 promotes lung adenocarcinoma progression by regulating miR-514a-3p to upregulate centrosome protein 55

Long noncoding RNAs are key players in the development of lung adenocarcinoma (LUAD). The present study elucidated the role of LINC01087 in LUAD development. Cell vitality and apoptosis were assessed by the CCK-8 assay and flow cytometry, respectively. The transwell assay was adopted to evaluate cell migration and invasion. Levels of m6A modification of LINC01087 were determined using the methylated RNA binding protein immunoprecipitation assay. The interactions among LINC01087, miR-514a-3p, and centrosome protein 55 (CEP55) were evaluated using dual-luciferase reporter, RNA immunoprecipitation, and RNA-RNA pull-down assays. LINC01087 was highly expressed in LUAD, and its downregulation restrained cancer cell proliferation, migration, invasion, and epithelial-mesenchymal transition in vitro as well as tumor growth in a xenograft tumor model. Overexpression of miR-514a-3p inhibited malignant phenotypes in LUAD cells by inactivating RhoA/ROCK1 signaling via the suppression of CEP55 expression. Mechanistically, RBM15 increased the expression and mRNA stability of LINC01087 by mediating its m6A modification and LINC01087 induced CEP55 expression by sponging miR-514a-3p. RBM15-induced LINC01087 upregulation accelerated LUAD progression by regulating the miR-514a-3p/CEP55/RhoA/ROCK1 axis, illustrating the potential of LINC01087 as a novel target for LUAD therapy.

DNAJB8 oligomerization is mediated by an aromatic-rich motif that is dispensable for substrate activity

J-domain protein (JDP) molecular chaperones have emerged as central players that maintain a healthy proteome. The diverse members of the JDP family function as monomers/dimers and a small subset assemble into micron-sized oligomers. The oligomeric JDP members have eluded structural characterization due to their low-complexity, intrinsically disordered middle domains. This in turn, obscures the biological significance of these larger oligomers in protein folding processes. Here, we identified a short, aromatic motif within DNAJB8 that drives self-assembly through π-π stacking and determined its X-ray structure. We show that mutations in the motif disrupt DNAJB8 oligomerization in vitro and in cells. DNAJB8 variants that are unable to assemble bind to misfolded tau seeds more specifically and retain capacity to reduce protein aggregation in vitro and in cells. We propose a new model for DNAJB8 function in which the sequences in the low-complexity domains play distinct roles in assembly and substrate activity.

DNAJB8 oligomerization is mediated by an aromatic-rich motif that is dispensable for substrate activity

J-domain protein (JDP) molecular chaperones have emerged as central players that maintain a healthy proteome. The diverse members of the JDP family function as monomers/dimers and a small subset assemble into micron-sized oligomers. The oligomeric JDP members have eluded structural characterization due to their low-complexity, intrinsically disordered middle domains. This in turn, obscures the biological significance of these larger oligomers in protein folding processes. Here, we identified a short, aromatic motif within DNAJB8, that drives self-assembly through pi-pi stacking and determined its X-ray structure. We show that mutations in the motif disrupt DNAJB8 oligomerization in vitro and in cells. DNAJB8 variants that are unable to assemble bind to misfolded tau seeds more specifically and retain capacity to reduce protein aggregation in vitro and in cells. We propose a new model for DNAJB8 function in which the sequences in the low-complexity domains play distinct roles in assembly and substrate activity.

Centrosomal Protein 55 (CEP55) Drives Immune Exclusion and Resistance to Immune Checkpoint Inhibitors in Colorectal Cancer

Colorectal cancer (CRC) currently ranks as the third most common cancer in the United States, and its incidence is on the rise, especially among younger individuals. Despite the remarkable success of immune checkpoint inhibitors (ICIs) in various cancers, most CRC patients fail to respond due to intrinsic resistance mechanisms. While microsatellite instability-high phenotypes serve as a reliable positive predictive biomarker for ICI treatment, the majority of CRC patients with microsatellite-stable (MSS) tumors remain ineligible for this therapeutic approach. In this study, we investigated the role of centrosomal protein 55 (CEP55) in shaping the tumor immune microenvironment in CRC. CEP55 is overexpressed in multiple cancer types and was shown to promote tumorigenesis by upregulating the PI3K/AKT pathway. Our data revealed that elevated CEP55 expression in CRC was associated with reduced T cell infiltration, contributing to immune exclusion. As CRC tumors progressed, CEP55 expression increased alongside sequential mutations in crucial driver genes (APC, KRAS, TP53, and SMAD4), indicating its involvement in tumor progression. CEP55 knockout significantly impaired tumor growth in vitro and in vivo, suggesting that CEP55 plays a crucial role in tumorigenesis. Furthermore, the CEP55 knockout increased CD8+ T cell infiltration and granzyme B production, indicating improved anti-tumor immunity. Additionally, we observed reduced regulatory T cell infiltration in CEP55 knockout tumors, suggesting diminished immune suppression. Most significantly, CEP55 knockout tumors demonstrated enhanced responsiveness to immune checkpoint inhibition in a clinically relevant orthotopic CRC model. Treatment with anti-PD1 significantly reduced tumor growth in CEP55 knockout tumors compared to control tumors, suggesting that inhibiting CEP55 could improve the efficacy of ICIs. Collectively, our study underscores the crucial role of CEP55 in driving immune exclusion and resistance to ICIs in CRC. Targeting CEP55 emerges as a promising therapeutic strategy to sensitize CRC to immune checkpoint inhibition, thereby improving survival outcomes for CRC patients.

Exploring olfactory receptor family 7 subfamily C member 1 as a novel oral cancer stem cell target for immunotherapy

The mortality rate of oral cancer has not improved over the past three decades despite remarkable advances in cancer therapies. Oral cancers contain a subpopulation of cancer stem cells (CSCs) that share characteristics associated with normal stem cells, including self-renewal and multi-differentiation potential. CSCs are tumorigenic, play a critical role in cancer infiltration, recurrence, and distant metastasis, and significantly contribute to drug resistance to current therapeutic strategies, including immunotherapy. Cytotoxic CD8+ T lymphocytes (CTLs) are key immune cells that effectively recognize peptide antigens presented by the major histocompatibility complex class I molecules. Increasing evidence suggests that cancer antigen-specific targeting by CTLs effectively regulates CSCs that drive cancer progression. In this study, we utilized data from public domains and performed various bioassays on human oral squamous cell carcinoma clinical samples and cell lines, including HSC-2 and HSC-3, to investigate the potential role of olfactory receptor family 7 subfamily C member 1 (OR7C1), a seven transmembrane G-protein-coupled olfactory receptor that is also expressed in nonolfactory tissues and was previously reported as a novel marker and target of colon cancer initiating cell-targeted immunotherapy, in CSC-targeted treatment against oral cancer. We found that the OR7C1 gene was expressed only in oral CSCs, and that CTLs reacted with human leukocyte antigen-A24-restricted OR7C1 oral CSC-specific peptides. Taken together, our findings suggest that OR7C1 represents a novel target for potent CSC-targeted immunotherapy in oral cancer.

Cancer-testis antigen CEP55 serves as a prognostic biomarker and is correlated with immune infiltration and immunotherapy efficacy in pan-cancer

Background: Centrosomal Protein 55 (CEP55) was initially described as a main participant in the final stage of cytokinesis. Further research identified CEP55 as a cancer-testis antigen (CTA) that is aberrantly expressed in different malignancies and a cancer vaccination candidate. The current study aimed to disclose the complete expression of CEP55, its effect on various malignancy prognoses, and its role in the tumor microenvironment. Methods: Transcriptional information regarding tumor and normal tissues, as well as externally validated and protein expression data were gathered from the Cancer Genome Atlas, Genotype-Tissue Expression project, Gene Expression Omnibus, and Human Protein Atlas. We examined the effect of CEP55 on tumor prognosis using Kaplan-Meier (KM) and univariate Cox regression analyses. In addition, we investigated the connections between CEP55 expression and hallmark cancer pathways, immune cell infiltration, and immune regulator expression across malignancies. We constructed and validated a CEP55-related risk model for hepatocellular carcinoma (HCC) and explored the correlations between CEP55 expression and HCC molecular subtypes. Finally, we investigated putative small-molecule drugs targeting CEP55 using a connectivity map (CMap) database and validated them using molecular docking analysis. Findings: CEP55 was aberrantly expressed in most cancers and revealed a prognostic value for several malignancies. Cancers with high CEP55 expression showed significantly enhanced cell cycle, proliferation, and immune-related pathways. For most malignancies, elevated CEP55 expression was associated with the infiltration of myeloid-derived suppressor cells (MDSCs) and Th2 cells. In addition, CEP55 expression was linked to immunomodulators and the potential prediction of immune checkpoint inhibitor (ICI) responses, and strongly associated with distinct molecular HCC subtypes, whereby the CEP55-based nomogram performed well in predicting short- and long-term HCC survival. Finally, we used connectivity map (CMap) and molecular docking analyses to discover three candidate small-molecule drugs that could directly bind to CEP55. Conclusion: CEP55 affected the occurrence and development of various cancers and possibly the regulation of the tumor immune microenvironment. Our findings suggest that CEP55 is a potential biomarker for prognosis and a powerful biomarker for ICI efficacy prediction.

Circular RNA_0120376 regulates microRNA-148b-3 and centrosomal protein 55 to promote non-small cell lung cancer development

Circular RNAs (circRNAs) are non-coding RNAs with covalent closed-loop structures that are vital in regulating diverse pathological processes. This work is aimed to investigate the role of circ_0120376 in non-small cell lung cancer (NSCLC). Circ_0120376, microRNA (miR)-148b-3p, and centrosomal protein 55 (CEP55) mRNA expression in NSCLC tissues and cells were determined using qRT-PCR. The influences of circ_0120376 and miR-148b-3p on the proliferation of NSCLC cell lines were analyzed by CCK-8 and colony formation assays. Apoptosis was analyzed by flow cytometry. Cell migration and invasion were analyzed using the Transwell experiment. Binding relationships between circ_0120376 and miR-148b-3p and between miR-148b-3p and CEP55 3'UTR were investigated using the dual-luciferase reporter experiment and the RIP experiment. Western blot was conducted to analyze the regulatory effect of circ_0120376 and miR-148b-3p on CEP55 expression. We found that circ_0120376 was markedly overexpressed in NSCLC, and its overexpression was positively associated with increased T stage and lymph node metastasis of the patients. Functional experiments unveiled that circ_0120376 enhanced the proliferation, migration and invasion of NSCLC cells and impeded apoptosis, while knocking down circ_0120376 remarkably suppressed the malignant features of NSCLC cells mentioned above. Circ_0120376 could adsorb miR-148b-3p to reduce miR-148b-3p expression, and circ_0120376 could increase CEP55 expression via adsorbing miR-148b-3p. In summary, circ_0120376 contributes to the malignancy of NSCLC cells through a ceRNA mechanism via regulating miR-148b-3p/CEP55 axis. Circ_0120376 is likely to be a potential diagnostic biomarker and therapeutic target for NSCLC.

High aldehyde dehydrogenase 1 activity is related to radiation resistance due to activation of AKT signaling after insulin stimulation in prostate cancer

The association between type 2 diabetes mellitus and prostate cancer is still under investigation, and the relationship between hyperinsulinemia and prostate cancer stem-like cells (CSCs) is elusive. Here, we investigated the function of insulin/AKT signaling in prostate CSCs. We isolated prostate CSCs as aldehyde dehydrogenase 1-high (ALDH1^high) cells from the human prostate cancer 22Rv1 cell line using an ALDEFLUOR assay and established several ALDH1^high and ALDH1^low clones. ALDH1^high clones showed high ALDH1 expression which is a putative CSC marker; however, they showed heterogeneity regarding tumorigenicity and resistance to radiation and chemotherapy. Interestingly, all ALDH1^high clones showed lower phosphorylated AKT (Ser473) (pAKT) levels than the ALDH1^low clones. PI3K/AKT signaling is a key cell survival pathway and we analyzed radiation resistance under AKT signaling activation by insulin. Insulin increased pAKT levels in ALDH1^high and ALDH1^low cells; the fold increase rate of pAKT was higher in ALDH1^high cells than in ALDH1^low cells. Insulin induced resistance to radiation and chemotherapy in ALDH1^high cells, and the increased levels of pAKT induced by insulin were significantly related to radiation resistance. These results suggest that ALDH1 suppresses baseline pAKT levels, but AKT can be activated by insulin, leading to treatment resistance.

Prognostic Nomogram Based on Circular RNA-Associated Competing Endogenous RNA Network for Patients with Lung Adenocarcinoma

Evidence is increasingly indicating that circular RNAs (circRNAs) are closely involved in tumorigenesis and cancer progression. However, the function and application of circRNAs in lung adenocarcinoma (LUAD) are still unknown. In this study, we constructed a circRNA-associated competitive endogenous RNA (ceRNA) network to investigate the regulatory mechanism of LUAD procession and further constructed a prognostic signature to predict overall survival for LUAD patients. Differentially expressed circRNAs (DEcircRNAs), differentially expressed miRNAs (DEmiRNAs), and differentially expressed mRNAs (DEmRNAs) were selected to construct the ceRNA network. Based on the TargetScan prediction tool and Pearson correlation coefficient, we constructed a circRNA-associated ceRNA network including 11 DEcircRNAs, 8 DEmiRNAs, and 49 DEmRNAs. GO and KEGG enrichment indicated that the ceRNA network might be involved in the regulation of GTPase activity and endothelial cell differentiation. After removing the discrete points, a PPI network containing 12 DEmRNAs was constructed. Univariate Cox regression analysis showed that three DEmRNAs were significantly associated with overall survival. Therefore, we constructed a three-gene prognostic signature for LUAD patients using the LASSO method in the TCGA-LUAD training cohort. By applying the signature, patients could be categorized into the high-risk or low-risk subgroups with significant survival differences (HR: 1.62, 95% CI: 1.12-2.35, log-rank p = 0.009). The prognostic performance was confirmed in an independent GEO cohort (GSE42127, HR: 2.59, 95% CI: 1.32-5.10, log-rank p = 0.004). Multivariate Cox regression analysis proved that the three-gene signature was an independent prognostic factor. Combining the three-gene signature with clinical characters, a nomogram was constructed. The primary and external verification C-indexes were 0.717 and 0.716, respectively. The calibration curves for the probability of 3- and 5-year OS showed significant agreement between nomogram predictions and actual observations. Our findings provided a deeper understanding of the circRNA-associated ceRNA regulatory mechanism in LUAD pathogenesis and further constructed a useful prognostic signature to guide personalized treatment of LUAD patients.

Identification of novel autoantibody signatures and evaluation of a panel of autoantibodies in breast cancer

Tumor-associated autoantibodies (TAAb) could be serological tumor markers. This study aims to discover novel TAAb signatures for breast cancer (BC) detection. The protein microarray was used to identify candidate TAAb, which were further validated in 1197 sera from BC, benign breast diseases (BD), and healthy controls (HC) by enzyme-linked immunosorbent assay. In addition, 319 preoperative and postoperative sera were evaluated. A panel was determined using four different classifiers. Twelve TAAb were identified with frequencies of 15.8%-59.2%; their levels were significantly decreased in postoperative sera compared to those in preoperative sera (P < .05). A panel with six TAAb was developed and evaluated. The area under the curve (AUC) was 0.879 (74.3% sensitivity, 91.9% specificity) and 0.865 (69.7% sensitivity, 91.7% specificity) for distinguishing BC from HC in the training set and test set, respectively. The panel had an AUC of .884 (71.2% sensitivity, 90.5% specificity) for discriminating BC from BD. For identifying BC from all controls (HC+BD), the AUC was .916 (78.9% sensitivity, 90.2% specificity). The AUC of the panel was .920 and .934 for distinguishing stage I-II and age < 50 BC from HC, respectively. These identified TAAb have the potential to provide a non-invasive approach to detect BC.

CEP55 Positively Affects Tumorigenesis of Esophageal Squamous Cell Carcinoma and Is Correlated with Poor Prognosis

Centrosomal protein 55 (CEP55) is a centrosome- and midbody-associated protein that is overexpressed in several cancers. However, the underlying molecular mechanism of CEP55-mediated progression and metastasis of esophageal squamous cell carcinoma (ESCC) is not clear. In the current study, we detected CEP55 mRNA by qRT-PCR while protein expression was detected by western blot analysis and immunohistochemistry (IHC). In addition, we knocked down CEP55 and investigated the ability of CEP55 to affect colony formation and migration. Here, we report that CEP55 mRNA and protein expression was significantly increased in ESCC. IHC staining showed that CEP55 expression correlated with TNM stage (p=0.046) and lymph node metastases (p=0.024). According to overall survival (OS) and disease-free survival (DFS), patients whose tumors expressed a higher level of CEP55 had a poorer prognosis than those with low expression level of CEP55. A multivariate analysis revealed that CEP55 expression was an independent prognostic indicator for patients with ESCC. Knockdown of CEP55 decreased the colony formation ability and migration of ESCC cells and also reduced the phosphorylation of Src, FAK, and ERK. Therefore, our study implied that CEP55 may be a valuable biomarker and a potential target in the treatment of patients with ESCC.

Cancer/testis antigens: from serology to mRNA cancer vaccine

Cancer/testis antigens (CTAs) are a group of tumor antigens expressed in numerous cancer tissues, as well as in the testis and placental tissues. There are over 200 CTAs supported by serology and expression data. The expression patterns of CTAs reflect the similarities between the processes of gametogenesis and tumorigenesis. It is notable that CTAs are highly expressed in three types of cancers (lung cancer, bladder cancer, and skin cancer), all of which have a metal etiology. Here, we review the expression, regulation, and function of CTAs and their translational prospects as cancer biomarkers and treatment targets. Many CTAs are highly immunogenic, tissue-specific, and frequently expressed in cancer tissues but not under physiological conditions, rendering them promising candidates for cancer detection. Some CTAs are associated with clinical outcomes, so they may serve as prognostic biomarkers. A small number of CTAs are membrane-bound, making them ideal targets for chimeric antigen receptor (CAR) T cells. Mounting evidence suggests that CTAs induce humoral or cellular immune responses, providing cancer immunotherapeutic opportunities for T-cell receptors (TCRs), CAR T cell, antibody-based therapy and peptide- or mRNA-based vaccines. Indeed, CTAs are the dominating non-mutated targets in mRNA cancer vaccine development. Clinical trials on CTA TCR and vaccines have shown effectiveness, safety, and tolerance, but these successes are limited to a small number of patients. In-depth studies on CTA expression and function are needed to improve CTA-based immunotherapy.

The RNA-helicase DDX21 upregulates CEP55 expression and promotes neuroblastoma

Approximately 25% of human neuroblastoma is caused by amplification of the MYCN oncogene, which leads to overexpression of N-Myc oncoprotein. The survival rate for this patient subtype is <50%. Here, we show that N-Myc protein bound to the DEAD-box RNA helicase DDX21 gene promoter and upregulated DDX21 mRNA and protein expression. Genome-wide differential gene expression studies identified centrosomal protein CEP55 as one of the genes most dramatically downregulated after DDX21 knockdown in MYCN-amplified neuroblastoma cells. Knocking down DDX21 or CEP55 reduced neuroblastoma cell cytoskeleton stability and cell proliferation and all but abolished clonogenic capacity. Importantly, DDX21 knockdown initially induced tumor regression in neuroblastoma-bearing mice and suppressed tumor progression. In human neuroblastoma tissues, a high level of DDX21 expression correlated with a high level of N-Myc expression and with CEP55 expression, and independently predicted poor patient prognosis. Taken together, our data show that DDX21 induces CEP55 expression, MYCN-amplified neuroblastoma cell proliferation, and tumorigenesis, and that DDX21 and CEP55 are valid therapeutic targets for the treatment of MYCN-amplified neuroblastoma.

Neuregulin-1-β1 and γ-secretase play a critical role in sphere-formation and cell survival of urothelial carcinoma cancer stem-like cells

Previously, we investigated gene expression in a high aldehyde dehydrogenase 1 expression (ALDH1^high) population of urothelial carcinoma (UC) cells as UC cancer stem-like cells (CSCs)/cancer-initiating cells (CICs) and found that NRG1 expression was upregulated in ALDH1^high cells. NRG1 is a trophic factor that contains an epidermal growth factor (EGF)-like domain that signals by stimulating ERBB receptor tyrosine kinases and the cytoplasmic domain. NRG1 has been determined to be involved in frequent gene fusions with other partners in several malignancies and has a role in carcinogenesis through the NRG1 EGF-like domain and its cognitive receptor ERBBs. We thus aimed to elucidate the function of NRG1 in UC CSCs/CICs in this study. Both NRG1α and NRG1-β1 were preferentially expressed in ALDH1^high cells compared with ALDH1^low cells; however, siRNA experiments revealed that NRG1-β1 but not NRG1-α has a role in sphere formation. The EGF-like domain of NRG1 had a role in sphere formation of UC cells to some extent but was not essential. The intracellular domain of NRG1 did not have a role in sphere-formation. Inhibition of γ-secretase suppressed sphere formation. These findings indicate that cleavage of NRG1-β1 by γ-secretase plays an important role in UC CSC/CIC proliferation; however, the downstream targets of NRG1-β1 remain elusive.

Cytotoxic T lymphocytes: Sniping cancer stem cells

Cancer stem cells (CSCs)/cancer-initiating cells (CICs) are characterized as a small population of cancer cells that have high tumor-initiating ability. CSCs/CICs are resistant to several cancer therapies, and eradication of CSCs/CICs is essential to cure cancer. How can we eradicate CSCs/CICs? Cytotoxic T lymphocytes (CTLs) might be a promising answer.

Expression, association with clinicopathological features and prognostic potential of CEP55, p-Akt, FoxM1 and MMP-2 in astrocytoma

Centrosomal protein 55 (CEP55) is a member of the centrosomal-associated protein family and participates in the regulation of cytokinesis during cell mitosis. However, aberrant CEP55 protein expression has been observed in human tumors. In addition, CEP55 regulates the biological functions of tumors by inducing the Akt pathway and upregulating forkhead box protein M1 (FoxM1) and matrix metalloproteinase-2 (MMP-2). In the present study, the levels, clinicopathological features and prognostic potential of CEP55, phosphorylated Akt (p-Akt), FoxM1 and MMP-2 in astrocytoma were evaluated. CEP55, p-Akt, FoxM1 and MMP-2 levels were examined in 27 normal brain tissues and 262 astrocytoma tissues by using immunohistochemistry. Furthermore, Kaplan-Meier analysis and Cox proportional hazards models were applied to predict the prognosis of patients with astrocytoma. The results indicated that expression levels of CEP55 and other proteins were elevated in human astrocytoma compared with those in normal brain tissue. The levels of the selected proteins were increased as the tumor grade increased. Furthermore, CEP55 expression was positively correlated with p-Akt, FoxM1 and MMP-2 levels in astrocytoma. Overall survival analysis revealed that patient prognosis was associated with CEP55, p-Akt, FoxM1 and MMP-2 levels, as well as with the tumor grade and patient age. Furthermore, CEP55, FoxM1, tumor grade and patient age were independent prognostic factors in astrocytoma according to multivariate analysis. Taken together, the present results suggested that CEP55, p-Akt, FoxM1 and MMP-2 have crucial roles in the progression and prognosis of human astrocytoma and that CEP55 and FoxM1 may be potential therapeutic targets.

The value of CEP55 gene as a diagnostic biomarker and independent prognostic factor in LUAD and LUSC

Objective

To investigate the value of CEP55 as a diagnostic marker and independent prognostic factor in lung adenocarcinoma (LUAD) and squamous cell carcinoma (LUSC), and to analyze its co-expression genes and related signaling pathways.

Methods

TCGA database and GEO database were used to analyze the expression of CEP55 in LUAD and LUSC compared with normal tissues. The co-expression genes of CEP55 in LUAD and LUSC were excavated by cBioPortal and enriched by KEGG and GO. Establishing Receiver operating characteristic (ROC) curve to evaluate the value of CEP55 as a diagnostic and prognostic factor. The association between CEP55 expression and the clinicopathological features was evaluated using χ2 tests. ROC curves for diagnosis and prognosis detection were constructed. Prognostic values were analyzed by univariate and multivariate Cox regression models.

Results

Compared with normal lung tissues, CEP55 expression was significantly upregulated in both LUAD and LUSC. ROC curve analysis showed that CEP55 could be used as an effective diagnostic target for LUAD (AUC = 0.969) and LUSC (AUC = 0.994). When CEP55 gene was selected as an independent prognostic factor, high expression of CEP55 was more disadvantageous to OS and RFS of LUAD patients (P<0.05), but no significant difference was found in LUSC patients (P>0.05). The number of co-expression genes of CEP55 in LUAD is more than that in LUSC, and is related to cell cycle, DNA replication and P53 signaling pathway.

Conclusion

CEP55 can be used as a diagnostic marker for LUAD and LUSC, but only as an independent prognostic factor for LUAD rather than LUSC.

Centrosomal protein 55: A new paradigm in tumorigenesis

Centrosomal Protein 55 (Cep55), also known as c10orf3 and FLJ10540, was initially discovered as a major player in abscission, the final stage of cytokinesis. Subsequent studies have described its role in regulating the PI3K/AKT pathway, increasing cancer cell stemness, and promoting tumor formation. Clinically, Cep55 has been found to be overexpressed in many cancer types. Cep55 overexpression has been notably associated with tumor stage, tumor aggressiveness, poor prognosis, and metastasis. The present review discusses the role of Cep55 as a crucial biomarker and model in tumorigenesis.

PART1 and hsa-miR-429-Mediated SHCBP1 Expression Is an Independent Predictor of Poor Prognosis in Glioma Patients

Gliomas are the most common primary brain tumors. Because of their high degree of malignancy, patient survival rates are unsatisfactory. Therefore, exploring glioma biomarkers will play a key role in early diagnosis, guiding treatment, and monitoring the prognosis of gliomas. We found two lncRNAs, six miRNAs, and nine mRNAs that were differentially expressed by analyzing genomic data of glioma patients. The diagnostic value of mRNA expression levels in gliomas was determined by receiver operating characteristic (ROC) curve analysis. Among the nine mRNAs, the area under the ROC curve values of only CEP55 and SHCBP1 were >0.7, specifically 0.834 and 0.816, respectively. Additionally, CEP55 and SHCBP1 were highly expressed in glioma specimens and showed increased expression according to the glioma grade, and outcomes of high expression patients were poor. CEP55 was enriched in the cell cycle, DNA replication, mismatch repair, and P53 signaling pathway. SHCBP1 was enriched in the cell cycle, DNA replication, ECM receptor interaction, and P53 signaling pathway. Age, grade, IDH status, chromosome 19/20 cogain, and SHCBP1 were independent factors for prognosis. Our findings suggest the PART1-hsa-miR-429-SHCBP1 regulatory network plays an important role in gliomas.

Upregulation of CEP55 Predicts Dismal Prognosis in Patients with Liver Cancer

Purpose

This study was performed to investigate the association of CEP55 expression with liver cancer and explore potential underlying mechanisms. Materials and Methods. Data obtained from The Cancer Genome Atlas (TCGA) was used to investigate CEP55 expression, its prognostic value, the potential mechanisms of its upregulation, CEP55-related pathways, and its biological functions in liver cancer. Data from Gene Expression Omnibus (GEO) and International Cancer Genome Consortium (ICGC) was used to validate survival analysis. The correlation between CEP55 and tumor-infiltrating immune cells (TIICs) in liver cancer was determined by using Tumor Immune Estimation Resource (TIMER).

Results

CEP55 was significantly overexpressed in the liver tumor sample compared to the adjacent normal liver sample. High CEP55 expression was significantly associated with histological grade, advanced stages, histological type, high T classification, and survival status. High CEP55 expression was significantly related to dismal prognosis compared with low CEP55 expression, which was validated by the GSE54236 dataset and ICGC database. Meanwhile, CEP55 was identified as the risk factor to independently predict overall survival (OS) for patients with liver cancer upon multivariate analysis. Enrichment analysis indicated that cell cycle, DNA replication, pathways in cancer, mTOR signaling pathway, and VEGF signaling pathway were significantly enriched in the high CEP55 expression group. In addition, the CEP55 expression was significantly related to the infiltration level of B cells, CD4+ T cells, CD8+ T cells, macrophages, neutrophils, and dendritic cells in hepatocellular carcinoma (HCC). CEP55 methylation level was negatively correlated to its mRNA expression. And patients with CEP55 hypermethylation and low expression can achieve a better prognosis than those with CEP55 hypomethylation and high expression.

Conclusion

CEP55 may serve as a candidate treatment target for it is a determinant of prognosis and immune infiltration in liver cancer patients. DNA hypomethylation might contribute to the overexpression of CEP55 in liver cancer.

Cellular immune responses against cancer-germline genes in cancers

BACKGROUND

Cancer-germline genes are a class of genes that are normally expressed in testis, trophoblast and few somatic tissues but abnormally expressed in tumor tissues. Their expression signature indicates that they can induce cellular immune responses, thus being applied as targets in cancer immunotherapy.

OBJECTIVES

To obtain the data of cellular immune responses against cancer-germline genes in cancer.

METHODS

We searched PubMed/Medline with the key words cancer-germline antigen, cancer-testis antigen, CD4+ T cell, CD8+ T cell and cancer.

RESULTS

About 40 cancer-germline genes have been shown to induce T cell specific responses in cancer patients. Melanoma, lung and breast cancer are among the mostly assessed cancer types. Several epitopes have been identified which can be used in immunotherapy of cancer.

CONCLUSION

Cellular immune responses against cancer-germline genes are indicative of appropriateness of these genes as therapeutic targets.

CEP55 is a determinant of cell fate during perturbed mitosis in breast cancer

The centrosomal protein, CEP55, is a key regulator of cytokinesis, and its overexpression is linked to genomic instability, a hallmark of cancer. However, the mechanism by which it mediates genomic instability remains elusive. Here, we showed that CEP55 overexpression/knockdown impacts survival of aneuploid cells. Loss of CEP55 sensitizes breast cancer cells to anti‐mitotic agents through premature CDK1/cyclin B activation and CDK1 caspase‐dependent mitotic cell death. Further, we showed that CEP55 is a downstream effector of the MEK1/2‐MYC axis. Blocking MEK1/2‐PLK1 signaling therefore reduced outgrowth of basal‐like syngeneic and human breast tumors in in vivo models. In conclusion, high CEP55 levels dictate cell fate during perturbed mitosis. Forced mitotic cell death by blocking MEK1/2‐PLK1 represents a potential therapeutic strategy for MYC‐CEP55‐dependent basal‐like, triple‐negative breast cancers.

Diagnostic and prognostic value of CEP55 in clear cell renal cell carcinoma as determined by bioinformatics analysis

Clear cell renal cell carcinoma (ccRCC) is one of the most common types of malignant adult kidney tumor. Tumor recurrence and metastasis is the primary cause of cancer-associated mortality in patients with ccRCC. Therefore, identification of efficient diagnostic and prognostic molecular markers may improve survival times. The GSE46699, GSE36895, GSE53000 and GSE53757 gene datasets were downloaded from the Gene Expression Omnibus database and contained 196 ccRCC samples and 164 adjacent normal kidney samples. Bioinformatics analysis was used to integrate the four microarray datasets to identify and analyze differentially expressed genes. Functional analysis revealed that there were 12 genes associated with cancer, based on the tumor-associated gene database. Erb-B2 receptor tyrosine kinase 4, centrosomal protein 55 (CEP55) and vascular endothelial growth factor A are oncogenes, all of which were associated with tumor stage, whereas only CEP55 was significantly associated with survival time as determined by Gene Expression Profiling Interactive Analysis. The mRNA expression levels of CEP55 in ccRCC samples were significantly higher than those observed in adjacent normal kidney tissues based on The Cancer Genome Atlas data and reverse transcription-polymerase chain reaction results. The receiver operating characteristic curve analysis revealed that CEP55 may be considered a diagnostic biomarker for ccRCC with an area under the curve of >0.85 in the training and validation sets. High CEP55 expression was strongly associated with sex, histological grade, stage, T classification, N classification and M classification. Univariate and multivariate Cox proportional hazards analyses demonstrated that CEP55 expression was an independent risk factor for poor prognosis. In addition, gene set enrichment analysis indicated that high CEP55 expression was associated with immunization, cell adhesion, inflammation, the Janus kinase/signal transducer and activator of transcription signaling pathway and cell proliferation. In conclusion, CEP55 was increased in ccRCC samples, and may be considered a potential diagnostic and prognostic biomarker for ccRCC.

Mitotic slippage: an old tale with a new twist

Targeting the mitotic machinery using anti-mitotic drugs for elimination of cancer cells is a century-old concept, which continues to be routinely used as a first line of treatment in the clinic. However, patient response remains unpredictable and drug resistance limits effectiveness of these drugs. Cancer cells exit from drug-induced mitotic arrest (mitotic slippage) to avoid subsequent cell death which is thought to be a major mechanism contributing to this resistance. The tumor cells that acquire resistance to anti-mitotic drugs have chromosomal instability (CIN) and are often aneuploid. In this review, we outline the key mechanisms involved in dictating the cell fate during perturbed mitosis and how these processes impede the efficacy of anti-mitotic therapies. Further, we emphasize the recent work from our laboratory, which highlights the functional role of CEP55 in protecting aneuploid cells from death. We also discuss the rationale of targeting CEP55 in vivo, which could prove to be a novel and effective therapeutic strategy for sensitizing cells to microtubule inhibitors and might offer significantly improved patient outcome. Abbreviations: APC/C: Anaphase-Promoting Complex/Cyclosome; BAD: BCL2-Associated agonist of cell Death; BAK1: BCL2 Antagonist Kinase1; BAX: BCL2-Associated X; BCL2: B-cell Chronic Lymphocytic Leukaemia (CLL)/Lymphoma 2; BH: BCL2 Homology Domain; BID: BH3-Interacting domain Death agonist; BIM: BCL2-Interacting Mediator of cell death; BUB: Budding Uninhibited by Benzimidazoles; CDC: Cell Division Cycle; CDH1: Cadherin-1; CDK1: Cyclin-Dependent Kinase 1; CEP55: Centrosomal Protein (55 KDa): CIN: Chromosomal Instability; CTA: Cancer Testis Antigen; EGR1: Early Growth Response protein 1; ERK: Extracellular Signal-Regulated Kinase; ESCRT: Endosomal Sorting Complexes Required for Transport; GIN: Genomic Instability; MAD2: Mitotic Arrest Deficient 2; MCL1: Myeloid Cell Leukemia sequence 1; MPS1: Monopolar Spindle 1 Kinase; MYT1: MYelin Transcription factor 1; PLK1: Polo Like Kinase 1; PUMA: p53-Upregulated Mediator of Apoptosis; SAC: Spindle Assembly Checkpoint; TAA: Tumor-Associated Antigen.

Molecular pathways of oral cancer that predict prognosis and survival: A systematic review

Several genes and pathways associated with oral squamous cell carcinoma (OSCC) are significant in terms of early detection and prognosis. The objective of this literature review is to evaluate the current research on molecular pathways and genes involved in oral cancer. Articles on the genes involved in oral cancer pathways were evaluated to identify potential biomarkers that can predict survival. In total, 36 articles were retrieved from internet databases, including EBSCO Host, Google Scholar, PubMed, and Science Direct, using the keywords "biomarker of oral cancer," "pathways of oral cancer," "genes involved in oral cancer," and "oral cancer pathways." A total of 36 studies related to OSCC were chosen. Most of the studies used cell lines, while others used archival tissues, few studies followed up the cases. Three major interlinked pathways found were the nuclear factor kappa B (NF-kB), PI3K-AKT, and Wnt pathways. The commonly mutated genes were cyclin D1 (CCND1), Rb, p53, FLJ10540, and TC21. The NF-kB, PI3K-AKT, and Wnt pathways are most frequently involved in the molecular pathogenesis of oral cancer. However, the CCND1, Rb, p53, FLJ10540, and TC21 genes were found to be more accurate in determining patients' overall survival. Polymerase chain reaction, immunohistochemistry, and immunoblotting were the commonly used detection methods.

CEP55 promotes the proliferation and invasion of tumour cells via the AKT signalling pathway in osteosarcoma

The molecular mechanisms underlying the development of osteosarcoma (OS) are not fully understood. In this study, we investigated for the first time the clinical significance and biological activity of centrosomal protein 55 (CEP55) in OS. We found that CEP55 was overexpressed in OS, and the CEP55 expression level in OS was correlated with metastasis and poor prognosis. Through in vitro experiments, we confirmed that CEP55 knockdown significantly induced cell cycle arrest at G1 phase and suppressed OS cell proliferation, migration and invasion. In addition, CEP55 knockdown suppressed OS tumour growth in nude mice. Global gene expression profiling of CEP55-silenced MNNG/HOS cells showed that the AKT pathway might be involved in the regulation of OS cell activity. Two downstream factors of AKT signalling, CCND1 and FN1, were found to have significantly higher expression in tumour tissues, and their mRNA expression levels were strongly correlated with CEP55 expression. To conclude, our data suggest that CEP55 can be used as a prognostic marker for OS, highlighting the significance of CEP55 signalling as a putative therapeutic target.

Emerging Contributions of Cancer/Testis Antigens to Neoplastic Behaviors

Tumors of nearly every origin activate the expression of genes normally restricted to gametogenic cells. These genes encode proteins termed cancer/testis (CT) antigens, since expression outside of their naturally immune-privileged site can evoke an immune response. Despite extensive efforts to exploit CT antigens as immunotherapeutic targets, investigation of whether these proteins participate in tumorigenic processes has lagged. Here, we discuss emerging evidence that demonstrates that CT antigens can confer a selective advantage to tumor cells by promoting oncogenic processes or permitting evasion of tumor-suppressive mechanisms. These advances indicate the inherent flexibility of tumor cell regulatory networks to engage aberrantly expressed proteins to promote neoplastic behaviors, which could ultimately present novel therapeutic entry points.

High CEP55 expression is associated with poor prognosis in non-small-cell lung cancer

Objectives

Lung cancer is the most common and lethal malignancy worldwide. CEP55 was found to be overexpressed in multiple types of cancer. However, the expression pattern of CEP55 and its clinical significance in non-small-cell lung carcinoma (NSCLC) have not been investigated by immunohistochemistry.

Materials and methods

In this study, we analyzed 203 primary NSCLC specimens from Sun Yat-Sen University Cancer Center to investigate the clinical role of CEP55 in lung cancer. Tissue microarray was successfully generated for immunohistochemical evaluation. The correlation between CEP55 expression and clinical characteristics and survival was analyzed statistically. The predictive effect of CEP55 and APOBEC3B (AP3B) coexpression in lung cancer patients’ prognosis was evaluated.

Results

We found that the CEP55 expression was commonly elevated in NSCLC tissues and overexpression of CEP55 was correlated with unfavorable prognosis in the patients with NSCLC. Furthermore, the combination of CEP55 and AP3B expression was significantly predictive of clinical outcome in all NSCLC patients.

Conclusion

CEP55 may act as a useful and novel prognostic biomarker for NSCLC. Further studies into the mechanism of CEP55 are warranted.

Clinical relevance of cytoskeleton associated proteins for ovarian cancer

PURPOSE

Ovarian cancer has a high mortality rate and up to now no reliable molecular prognostic biomarkers have been established. During malignant progression, the cytoskeleton is strongly altered. Hence we analyzed if expression of certain cytoskeleton-associated proteins is correlated with clinical outcome of ovarian cancer patients.

METHODS

First, in silico analysis was performed using the cancer genome atlas (TCGA), the human expression atlas and Pubmed. Selected candidates were validated on 270 ovarian cancer patients by qRT-PCR and/or by western blotting.

RESULTS

In silico analysis revealed that mRNAs of 214 cytoskeleton-associated proteins are detectable in ovarian cancer tissue. Among these, we selected 17 proteins that participate in cancer disease progression and cytoskeleton modulation: KIF14, KIF20A, KIF18A, ASPM, CEP55, DLGAP5, MAP9, EB1, KATNA1, DIAPH1, ANLN, SCIN, CCDC88A, FSCN1, GSN, VASP and CDC42. The first ten candidates interact with microtubules (MTs) and the others bind to actin filaments. Validation on clinical samples of ovarian cancer patients revealed that the expression levels of DIAPH1, EB1, KATNA1, KIF14 and KIF18A significantly correlated with clinical and histological parameters of ovarian cancer. High DIAPH1, EB1, KATNA1 and KIF14 protein levels were associated with increased overall survival (OAS) of ovarian cancer patients, while high DIAPH1 and EB1 protein levels were also associated with low differentiation of respective tumors (G2/3). Moreover, DIAPH1 was the only protein, whose expression significantly correlated with increased recurrence-free interval (RFI).

CONCLUSION

Mainly the expression levels of the MT-associated proteins analyzed in this study, correlated with prolonged survival of ovarian cancer patients. From > 200 genes initially considered, 17 cytoskeletal proteins are involved in cancer progression according to the literature. Among these, four proteins significantly correlated with improved survival of ovarian cancer patients.

Case report: Long-term survival of a pancreatic cancer patient immunized with an SVN-2B peptide vaccine

A 62-year-old woman who underwent surgery to treat pancreatic cancer provided written, informed consent to undergo adjuvant therapy with gemcitabine, tegafur, and uracil. However, this was stopped after only 14 days due to Grade 4 neutropenia. She was then started on vaccine therapy with Survivin 2B peptide (SVN-2B) including IFA and INF-α. Although metastatic lung tumors were identified and resected at 82 months after surgery, the patient has remained free of new or relapsed disease for 12 years thereafter. Tetramer and ELISPOT assays revealed the continuous circulation of SVN-2B-restricted cytotoxic T-lymphocytes (CTLs) in her peripheral blood, and CTL clones had specific activity for SVN-2B at 12 years after surgery. The adverse effects of the peptide vaccination were tolerable and comprised low-grade headache, nausea, and fatigue. A prognosis beyond 10 years in the face of pancreatic cancer with distant metastasis is extremely rare. This experience might indicate the value of cancer vaccination therapy.

Prognostic significance of Cep55 in oral squamous cell carcinoma

Objective:

Currently, oral squamous cell carcinoma (OSCC) is one of the most fatal cancers of all head and neck malignancies. Despite advancements in therapy, the mortality and morbidity remain high. Hence, it is essential to identify useful prognostic markers for high-risk individuals with OSCC to decide on treatment protocols. Centrosomal protein 55 ( Cep55), a regulator of the cell cycle, has been considered to play a role in carcinogenesis. Although there are numerous studies on its role in various other epithelial cancers such as breast, ovarian and lung cancers, its significance in the behaviour of OSCC is yet to be studied. The present study aimed to study Cep55 expression in OSCC and correlate with the tumour characteristics and patient survival.

Materials and Methods:

Forty pathologically diagnosed cases of OSCC were included in the study: 20 each of early and advanced OSCC cases. Formalin-fixed paraffin-embedded archival samples were used. The sections were immunohistochemically stained with Cep55 antibody. The expression levels of Cep55 were correlated with clinical parameters and disease outcome.

Results:

A higher expression of Cep55 was observed in advanced stage compared to early stage of OSCC. The Cep55 expression showed no significant relation with respect to clinical staging, pathological grading and site, except for tongue. Cep55 overexpression is significantly associated with poor survival.

Conclusion:

The present study suggests that Cep55 could play an important role in determining the biological behaviour and survival of OSCC patients independent of tumour staging and pathological grading. Thus, assessment of Cep55 expression could navigate the surgeons to plan an appropriate treatment.

Cep55 overexpression causes male-specific sterility in mice by suppressing Foxo1 nuclear retention through sustained activation of PI3K/Akt signaling

Spermatogenesis is a dynamic process involving self-renewal and differentiation of spermatogonial stem cells, meiosis, and ultimately, the differentiation of haploid spermatids into sperm. Centrosomal protein 55 kDa (CEP55) is necessary for somatic cell abscission during cytokinesis. It facilitates equal segregation of cytoplasmic contents between daughter cells by recruiting endosomal sorting complex required for transport machinery (ESCRT) at the midbody. In germ cells, CEP55, in partnership with testes expressed-14 (TEX14) protein, has also been shown to be an integral component of intercellular bridge before meiosis. Various in vitro studies have demonstrated a role for CEP55 in multiple cancers and other diseases. However, its oncogenic potential in vivo remains elusive. To investigate, we generated ubiquitously overexpressing Cep55 transgenic ( Cep55^Tg/Tg) mice aiming to characterize its oncogenic role in cancer. Unexpectedly, we found that Cep55^Tg/Tg male mice were sterile and had severe and progressive defects in spermatogenesis related to spermatogenic arrest and lack of spermatids in the testes. In this study, we characterized this male-specific phenotype and showed that excessively high levels of Cep55 results in hyperactivation of PI3K/protein kinase B (Akt) signaling in testis. In line with this finding, we observed increased phosphorylation of forkhead box protein O1 (FoxO1), and suppression of its nuclear retention, along with the relative enrichment of promyelocytic leukemia zinc finger (PLZF) -positive cells. Independently, we observed that Cep55 amplification favored upregulation of ret ( Ret) proto-oncogene and glial-derived neurotrophic factor family receptor α-1 ( Gfra1). Consistent with these data, we observed selective down-regulation of genes associated with germ cell differentiation in Cep55-overexpressing testes at postnatal day 10, including early growth response-4 ( Egr4) and spermatogenesis and oogenesis specific basic helix-loop-helix-1 ( Sohlh1). Thus, Cep55 amplification leads to a shift toward the initial maintenance of undifferentiated spermatogonia and ultimately results in progressive germ cell loss. Collectively, our findings demonstrate that Cep55 overexpression causes change in germ cell proportions and manifests as a Sertoli cell only tubule phenotype, similar to that seen in many azoospermic men.-Sinha, D., Kalimutho, M., Bowles, J., Chan, A.-L., Merriner, D. J., Bain, A. L., Simmons, J. L., Freire, R., Lopez, J. A., Hobbs, R. M., O'Bryan, M. K., Khanna, K. K. Cep55 overexpression causes male-specific sterility in mice by suppressing Foxo1 nuclear retention through sustained activation of PI3K/Akt signaling.

Phosphorylation of HSF1 at serine 326 residue is related to the maintenance of gynecologic cancer stem cells through expression of HSP27

Cancer stem-like cells (CSCs)/ cancer-initiating cells (CICs) are defined by their higher tumor-initiating ability, self-renewal capacity and differentiation capacity. CSCs/CICs are resistant to several therapies including chemotherapy and radiotherapy. CSCs/CICs thus are thought to be responsible for recurrence and distant metastasis, and elucidation of the molecular mechanisms of CSCs/CICs are essential to design CSC/CIC-targeting therapy. In this study, we analyzed the molecular aspects of gynecological CSCs/CICs. Gynecological CSCs/CICs were isolated as ALDH1high cell by Aldefluor assay. The gene expression profile of CSCs/CICs revealed that several genes related to stress responses are preferentially expressed in gynecological CSCs/CICs. Among the stress response genes, a small heat shock protein HSP27 has a role in the maintenance of gynecological CSCs/CICs. The upstream transcription factor of HSP27, heat shock factior-1 (HSF1) was activated by phosphorylation at serine 326 residue (pSer326) in CSCs/CICs, and phosphorylation at serine 326 residue is essential for induction of HSP27. Immunohistochemical staining using clinical ovarian cancer samples revealed that higher expressions of HSF1 pSer326 was related to poorer prognosis. These findings indicate that activation of HSF1 at Ser326 residue and transcription of HSP27 is related to the maintenance of gynecological CSCs/CICs.

Cellular stress induces cancer stem-like cells through expression of DNAJB8 by activation of heat shock factor 1

In a previous study, we found that DNAJB8, a heat shock protein (HSP) 40 family member is expressed in kidney cancer stem‐like cells (CSC)/cancer‐initiating cells (CIC) and that it has a role in the maintenance of kidney CSC/CIC. Heat shock factor (HSF) 1 is a key transcription factor for responses to stress including heat shock, and it induces HSP family expression through activation by phosphorylation. In the present study, we therefore examined whether heat shock (HS) induces CSC/CIC. We treated the human kidney cancer cell line ACHN with HS, and found that HS increased side population (SP) cells. Western blot analysis and qRT‐PCR showed that HS increased the expression of DNAJB8 and SOX2. Gene knockdown experiments using siRNAs showed that the increase in SOX2 expression and SP cell ratio depends on DNAJB8 and that the increase in DNAJB8 and SOX2 depend on HSF1. Furthermore, treatment with a mammalian target of rapamycin (mTOR) inhibitor, temsirolimus, decreased the expression of DNAJB8 and SOX2 and the ratio of SP cells. Taken together, the results indicate that heat shock induces DNAJB8 by activation of HSF1 and induces cancer stem‐like cells.

The Effect of Mammary Extracellular Matrix in Controlling Oral and Mammary Cancer Cells

Extracellular matrix (ECM) plays an important role in the normal physiology of tissues and progression to disease. Earlier studies and our external microarray data analysis indicated that mammary matrix from involuting tissue showed upregulation of genes involved in ECM remodeling. The present study examines the fate of mammary and oral cancer cells grown in the ECM from lactating mammary gland. Our findings show that non-tumorigenic cells, MCF10A and DOK cells did not proliferate but the tumorigenic and metastatic cells, SCC25 and MDA-MB-231, underwent apoptosis when grown on mammary ECM isolated from lactating mice. In addition, the cytokinesis marker, CEP55, was repressed in the oral and breast cancer cells. In contrast, these cells proliferated normally on mammary ECM isolated from mice undergoing involution. External microarray data analysis of mammary tissue further revealed over expression (~16 fold) of QSOX1 gene, which promotes cellular quiescence, in lactating mammary gland. A recent study has indicated that QSOX1 overexpression in breast cancer cells led to reduced proliferation and tumorigenic properties. This extracellular protein in mammary ECM may be responsible for reduced cellular proliferation. The present study has shown that ECM from lactating mammary gland can regulate signals to oral and breast cancer cells to halt cell division. This preliminary observation provided insights into the potential role of ECM factors present in lactating mammary gland as therapeutic targets to control cancer cell division. This preliminary study is an attempt to understand not only the requirement of ECM remodeling factors essential for the growth and survival of cancer cells but also the factors present in the lactation matrix that simultaneously halts cell division and selectively inhibits the growth of cancer cells.

Brother of the regulator of the imprinted site (BORIS) variant subfamily 6 is involved in cervical cancer stemness and can be a target of immunotherapy

Cervical cancer is a major cause of cancer death in females worldwide. Cervical cancer stem-like cells (CSCs)/cancer-initiating cells (CICs) are resistant to conventional radiotherapy and chemotherapy, and CSCs/CICs are thought to be responsible for recurrence. Eradication of CSCs/CICs is thus essential to cure cervical cancer. In this study, we isolated cervical CSCs/CICs by sphere culture, and we identified a cancer testis (CT) antigen, CTCFL/BORIS, that is expressed in cervical CSCs/CICs. BORIS has 23 mRNA isoform variants classified by 6 subfamilies (sfs), and they encode 17 different BORIS peptides. BORIS sf1 and sf4 are expressed in both CSCs/CICs and non-CSCs/CICs, whereas BORIS sf6 is expressed only in CSCs/CICs. Overexpression of BORIS sf6 in cervical cancer cells increased sphere formation and tumor-initiating ability compared with those in control cells, whereas overexpression of BORIS sf1 and BORIS sf4 resulted in only slight increases. Thus, BORIS sf6 is a cervical CSC/CIC-specific subfamily and has a role in the maintenance of cervical CSCs/CICs. BORIS sf6 contains a specific c-terminal domain (C34), and we identified a human leukocyte antigen (HLA)-A2-restricted antigenic peptide, BORIS C34_24(9) encoded by BORIS sf6. A BORIS C34_24(9)-specific cytotoxic T cell (CTL) clone showed cytotoxicity for BORIS sf6-overexpressing cervical cancer cells. Furthermore, the CTL clone significantly suppressed sphere formation of CaSki cells. Taken together, the results indicate that the CT antigen BORIS sf6 is specifically expressed in cervical CSCs/CICs, that BORIS sf6 has a role in the maintenance of CSCs/CICs, and that BORIS C34_24(9) peptide is a promising candidate for cervical CSC/CIC-targeting immunotherapy.

Identification of antigenic peptides from novel renal cancer stem-like cell antigen, DNAJB8

OBJECTIVES

To identify antigenic peptides of cancer stem-like cells (CSCs) antigen, DNAJB8, and establish a mouse CSCs-targeting immunotherapy model.

MATERIALS AND METHODS

To induce DNAJB8-specific immune reaction, we stimulated human CD8⁺ lymphocytes with antigen-presenting cells pulsed with a cocktail of three candidate HLA-A*24:02 restricted peptides and assessed peptide specific human cytotoxic T lymphocytes (CTLs) induction. One of the antigenic peptides showed identical amino acid sequence as corresponding mouse DNAJB8. We evaluated CTL induction with the peptide immunization in mouse model.

RESULTS

We confirmed peptide-specific interferon-γ secretions and cytotoxic activities of induced human CTLs. In vivo immunization with the peptide to mice, peptide-specific CTL response could be observed in mouse CD8⁺ T cells. Furthermore, immunization with the peptide showed significant anti-tumor effects compared with negative controls.

CONCLUSION

DNAJB8-derived peptide is a novel candidate for CSCs-targeting immunotherapy, and mouse models can be used to evaluate CSCs-targeting immunotherapy.

GRIK2 has a role in the maintenance of urothelial carcinoma stem-like cells, and its expression is associated with poorer prognosis

Cancer stem-like cells (CSCs)/cancer-initiating cells (CICs) are small sub-population of cancer cells that are endowed with higher tumor-initiating ability, self-renewal ability and differentiation ability. CSCs/CICs could be isolated as high aldehyde dehydrogenase 1 activity cells (ALDH1high) from various cancer samples. In this study, we isolated urothelial carcinoma CSCs/CICs as ALDHhigh cells and investigated the molecular aspects. ALDH1high cells showed greater sphere-forming ability and higher tumor-initiating ability in immune-deficient mice than those of ALDH1low cells, indicating that CSCs/CICs were enriched in ALDH1high cells. cDNA microarray analysis revealed that an ionotropic glutamate receptor glutamate receptor, ionotropic, kainate 2 (GRIK2) was expressed in ALDH1high cells at a higher level than that in ALDH1low cells. GRIK2 gene knockdown by siRNAs decreased the sphere-forming ability and invasion ability, whereas GRIK2 overexpression increased the sphere-forming ability, invasion ability and tumorigenicity, indicating that GRIK2 has a role in the maintenance of CSCs/CICs. Immunohistochemical staining revealed that higher levels of GRIK2 and ALDH1 expression were related to poorer prognosis in urinary tract carcinoma cases. The findings indicate that GRIK2 has a role in the maintenance of urothelial CSCs/CICs and that GRIK2 and ALDH1 can be prognosis prediction markers for urinary tract carcinomas.

Cancer/Testis Antigens: "Smart" Biomarkers for Diagnosis and Prognosis of Prostate and Other Cancers

A clinical dilemma in the management of prostate cancer (PCa) is to distinguish men with aggressive disease who need definitive treatment from men who may not require immediate intervention. Accurate prediction of disease behavior is critical because radical treatment is associated with high morbidity. Here, we highlight the cancer/testis antigens (CTAs) as potential PCa biomarkers. The CTAs are a group of proteins that are typically restricted to the testis in the normal adult but are aberrantly expressed in several types of cancers. Interestingly, >90% of CTAs are predicted to belong to the realm of intrinsically disordered proteins (IDPs), which do not have unique structures and exist as highly dynamic conformational ensembles, but are known to play important roles in several biological processes. Using prostate-associated gene 4 (PAGE4) as an example of a disordered CTA, we highlight how IDP conformational dynamics may regulate phenotypic heterogeneity in PCa cells, and how it may be exploited both as a potential biomarker as well as a promising therapeutic target in PCa. We also discuss how in addition to intrinsic disorder and post-translational modifications, structural and functional variability induced in the CTAs by alternate splicing represents an important feature that might have different roles in different cancers. Although it is clear that significant additional work needs to be done in the outlined direction, this novel concept emphasizing (multi)functionality as an important trait in selecting a biomarker underscoring the theranostic potential of CTAs that is latent in their structure (or, more appropriately, the lack thereof), and casts them as next generation or “smart” biomarker candidates.

BCIP: a gene-centered platform for identifying potential regulatory genes in breast cancer

Breast cancer is a disease with high heterogeneity. Many issues on tumorigenesis and progression are still elusive. It is critical to identify genes that play important roles in the progression of tumors, especially for tumors with poor prognosis such as basal-like breast cancer and tumors in very young women. To facilitate the identification of potential regulatory or driver genes, we present the Breast Cancer Integrative Platform (BCIP, http://omics.bmi.ac.cn/bcancer/). BCIP maintains multi-omics data selected with strict quality control and processed with uniform normalization methods, including gene expression profiles from 9,005 tumor and 376 normal tissue samples, copy number variation information from 3,035 tumor samples, microRNA-target interactions, co-expressed genes, KEGG pathways, and mammary tissue-specific gene functional networks. This platform provides a user-friendly interface integrating comprehensive and flexible analysis tools on differential gene expression, copy number variation, and survival analysis. The prominent characteristic of BCIP is that users can perform analysis by customizing subgroups with single or combined clinical features, including subtypes, histological grades, pathologic stages, metastasis status, lymph node status, ER/PR/HER2 status, TP53 mutation status, menopause status, age, tumor size, therapy responses, and prognosis. BCIP will help to identify regulatory or driver genes and candidate biomarkers for further research in breast cancer.

A truncating mutation in CEP55 is the likely cause of MARCH, a novel syndrome affecting neuronal mitosis

Background

Hydranencephaly is a congenital anomaly leading to replacement of the cerebral hemispheres with a fluid-filled cyst. The goals of this work are to describe a novel autosomal-recessive syndrome that includes hydranencephaly (multinucleated neurons, anhydramnios, renal dysplasia, cerebellar hypoplasia and hydranencephaly (MARCH)); to identify its genetic cause(s) and to provide functional insight into pathomechanism.

Methods

We used homozygosity mapping and exome sequencing to identify recessive mutations in a single family with three affected fetuses. Immunohistochemistry, RT-PCR and imaging in cell lines, and zebrafish models, were used to explore the function of the gene and the effect of the mutation.

Results

We identified a homozygous nonsense mutation in CEP55 segregating with MARCH. Testing the effect of this allele on patient-derived cells indicated both a reduction of the overall CEP55 message and the production of a message that likely gives rise to a truncated protein. Suppression or ablation of cep55l in zebrafish embryos recapitulated key features of MARCH, most notably renal dysplasia, cerebellar hypoplasia and craniofacial abnormalities. These phenotypes could be rescued by full-length but not truncated human CEP55 message. Finally, we expressed the truncated form of CEP55 in human cells, where we observed a failure of truncated protein to localise to the midbody, leading to abscission failure and multinucleated daughter cells.

Conclusions

CEP55 loss of function mutations likely underlie MARCH, a novel multiple congenital anomaly syndrome. This association expands the involvement of centrosomal proteins in human genetic disorders by highlighting a role in midbody function.

Brother of the regulator of the imprinted site (BORIS) variant subfamily 6 is a novel target of lung cancer stem-like cell immunotherapy

Lung cancer is one of the most common malignancies with a high rate of mortality. Lung cancer stem-like cells (CSCs)/ cancer-initiating cells (CICs) play major role in resistance to treatments, recurrence and distant metastasis and eradication of CSCs/CICs is crucial to improve recent therapy. Cytotoxic T lymphocytes (CTLs) are major effectors of cancer immunotherapy, and CTLs recognize antigenic peptides derived from antigens that are presented by major histocompatibility complex (MHC) class I molecules. In this study, we analyzed the potency of a cancer-testis (CT) antigen, brother of the regulator of the imprinted site variant subfamily 6 (BORIS sf6), in lung CSC/CIC immunotherapy. BORIS sf6 mRNA was expressed in lung carcinoma cells (9/19), especially in sphere-cultured lung cancer stem-like cells, and in primary lung carcinoma tissues (4/9) by RT-PCR. Immunohistochemical staining using BORIS sf6-specific antibody revealed that high expression of BORIS sf6 is related to poorer prognosis. CTLs could be induced by using a human leukocyte antigen, (HLA)-A2 restricted antigenic peptide (BORIS C34_24(9)), from all of 3 HLA-A2-positive individuals, and CTL clone cells specific for BORIS C34_24(9) peptide could recognize BORIS sf6-positive, HLA-A2-positive lung carcinoma cells. These results indicate that BORIS sf6 is a novel target of lung cancer immunotherapy that might be useful for targeting treatment-resistant lung cancer stem-like cells.

LY6/PLAUR domain containing 3 has a role in the maintenance of colorectal cancer stem-like cells

Colorectal carcinoma (CRC) is one of the most frequently diagnosed cancers and the leading cause of cancer-related death for both men and women. Recent studies have revealed that a small sub-population of cancer cells, termed cancer stem-like cells (CSCs)/cancer-initiating cells (CICs), are endowed with tumor-initiating ability, self-renewal ability and differentiation ability. CSCs/CICs are resistant to current therapies including chemotherapy and radiotherapy. Thus, CSCs/CICs are responsible for recurrence and metastasis, and eradication of CSCs/CICs is essential to cure cancer. In this study, we isolated CR-CSCs/CICs as sphere-cultured cells and found that a product derived from LY6/PLAUR domain containing 3 (LYPD3) is preferentially expressed in CSCs/CICs. Gene overexpression and gene knockdown experiments revealed that LYPD3 has a role in the maintenance of CR-CSCs/CICs. The findings provide a novel molecular insight into CR-CSCs/CICs.

Loss of tapasin in human lung and colon cancer cells and escape from tumor-associated antigen-specific CTL recognition

Cytotoxic T-lymphocytes (CTLs) lyse target cells after recognizing the complexes of peptides and MHC class I molecules (pMHC I) on cell surfaces. Tapasin is an essential component of the peptide-loading complex (PLC) and its absence influences the surface repertoire of MHC class I peptides. In the present study, we assessed tapasin expression in 85 primary tumor lesions of non-small cell lung cancer (NSCLC) patients, demonstrating that tapasin expression positively correlated with patient survival. CD8⁺ T-cell infiltration of tumor lesions was synergistically observed with tapasin expression and correlated positively with survival. To establish a direct link between loss of tapasin and CTL recognition in human cancer models, we targeted the tapasin gene by CRISPR/Cas9 system and generated tapasin-deficient variants of human lung as well as colon cancer cells. We induced the CTLs recognizing endogenous tumor-associated antigens (TAA), survivin or cep55, and they responded to each tapasin-proficient wild type. In contrast, both CTL lines ignored the tapasin-deficient variants despite their antigen expression. Moreover, the adoptive transfer of the cep55-specific CTL line failed to prevent tumor growth in mice bearing the tapasin-deficient variant. Loss of tapasin most likely limited antigen processing of TAAs and led to escape from TAA-specific CTL recognition. Tapasin expression is thus a key for CTL surveillance against human cancers.

CEP55 overexpression predicts poor prognosis in patients with locally advanced esophageal squamous cell carcinoma

Development of esophageal squamous cell carcinoma (ESCC) involves alterations in multiple genes with corresponding proteins. Recent studies have demonstrated that centrosomal protein 55 (CEP55) shares certain features with oncogenes, and CEP55 overexpression is associated with the development and progression of malignant tumors. The present study aimed to analyze, for the first time, whether CEP55 expression is related to clinicopothalogic features in the esophageal squamous cell carcinoma (ESCC), as well as patient survival. A total of 110 patients with mid-thoracic ESCC who suffered from Ivor-Lewis were enrolled. The CEP55 expression profile of these patients in tumour tissues and corresponding healthy esophageal mucosa (CHEM) was detected by immunohistochemistry and semi-quantitative reverse transcription-polymerase chain reaction analyses. Correlations between CEP55 expression and clinicopathological factors were analyzed using χ² test. The log-rank test was employed to calculate survival rate. A Cox regression multivariate analysis was performed to determine independent prognostic factors. The results demonstrated that CEP55 expression in ESCC was significantly higher than that of CHEM (P<0.001). Overexpression of CEP55 was significantly associated with differentiation degree (P=0.022), T stage (P=0.019), lymph node metastasis (P=0.033), clinicopathological staging (P=0.002) and tumor recurrence (P=0.021) in locally advanced ESCC patients. In addition, CEP55 overexpression was significantly associated with reduced overall survival of patients after surgery (P=0.012). The 5-year survival rate of patients without CEP55 overexpression was significantly higher than that of patients with CEP55 overexpression (P=0.012). Therefore, these findings suggest that CEP55 overexpression correlates with poor prognosis in locally advanced ESCC patients.

Lentivirus-mediated knockdown of CEP55 suppresses cell proliferation of breast cancer cells

Centrosomal protein 55 (CEP55), as a microtubule-bundling protein, plays an important role in cell cycle regulation. CEP55 has been recognized recently in several human cancers. In this study, we first observed that the mRNA level of CEP55 is commonly up-regulated in breast cancer compared with their normal counterparts as demonstrated by data derived from Oncomine database. To further evaluate the functional role of CEP55 in breast cancer cells. Expression of CEP55 was efficiently knocked down using lentivirus-mediated RNA interference in human breast cancer cell line ZR-75-30, as evidenced by quantitative real-time PCR (qRT-PCR) and Western blot analysis. Further investigations revealed that CEP55 knockdown significantly inhibited cell proliferation and colony formation. Moreover, flow cytometer analysis indicated knockdown of CEP55 induced cell cycle arrested at G0/G1 phase and cell apoptosis. These findings suggest that CEP55 plays a crucial role in promoting breast cancer cell proliferation and it might be a potential therapeutic target in breast cancer.

Olfactory Receptor Family 7 Subfamily C Member 1 Is a Novel Marker of Colon Cancer-Initiating Cells and Is a Potent Target of Immunotherapy

PURPOSE

Cancer-initiating cells (CICs) are thought to be essential for tumor maintenance, recurrence, and distant metastasis, and they are therefore reasonable targets for cancer therapy. Cancer immunotherapy is a novel approach to target cancer. In this study, we aimed to establish novel CIC-targeting immunotherapy.

EXPERIMENTAL DESIGN

Colorectal cancer (CRC) CICs were isolated as side population (SP) cells. The gene expression profile of CRC CICs was analyzed by cDNA microarray and RT-PCR. Protein expression of olfactory receptor family 7 subfamily C member 1 (OR7C1) were analyzed by Western blot and immunohistochemical staining. The functions of OR7C1 were analyzed by gene overexpression and gene knockdown using siRNAs. OR7C1-positive cells were isolated by a flow cytometer and analyzed. CTLs specific for OR7C1 peptide were generated, and the antitumor effect was addressed by mice adoptive transfer model.

RESULTS

OR7C1 has essential roles in the maintenance of colon CICs, and the OR7C1-positive population showed higher tumorigenicity than that of the OR7C1-negative population, indicating that OR7C1 is a novel functional marker for colon CIC. Immunohistochemical staining revealed that OR7C1 high expression was correlated with poorer prognosis in CRC patients. OR7C1-derived antigenic peptide-specific CTLs showed specific cytotoxicity for CICs, and an OR7C1-specific CTL clone showed a greater antitumor effect than did a CTL clone targeting all cancer cells in a CTL adoptive transfer mouse model.

CONCLUSIONS

OR7C1 is a novel marker for colon CICs and can be a target of potent CIC-targeting immunotherapy. Clin Cancer Res; 22(13); 3298-309. ©2016 AACR.

Prognostic significance of centrosomal protein 55 in stage I pulmonary adenocarcinoma after radical resection

Background

Pulmonary adenocarcinoma is a predominant pathologic non‐small cell lung cancer (NSCLC) with a high morbidity in China. Even at histological stage I, many patients still experience recurrence after radical surgery; therefore, it is critical to determine useful indicators to stratify patients according to recurrent risk. Centrosomal protein 55 (CEP55) shares certain characteristics with oncogenes and aberrant expression of CEP55 can lead to tumorigenesis. Therefore, we aimed to clarify the clinicopathological significance and prognostic value of CEP55 in stage I pulmonary adenocarcinoma.

Methods

We enrolled 106 patients with stage I pulmonary adenocarcinoma who had received complete resection in our study. CEP55 expression levels in the pulmonary tissues of all patients were validated by Western blot analyses and immunohistochemistry. SPSS 17.0 software was employed to analyze the correlation between CEP55 expression and clinicopathological characteristics of patients, as well as prognosis.

Results

CEP55 overexpression was detected in 67 patients (63.2%). Overexpression is associated with tumor differentiation (P = 0.036), T stage (P = 0.000) and visceral pleural invasion (P = 0.009). Patients with CEP55 overexpression had worse survival compared with those with low expression (P = 0.043). Univariate analysis revealed that T stage (P = 0.000), differentiation degree (P = 0.002), visceral pleural invasion (P = 0.000), and tumor size (P = 0.013) were also significant prognostic factors.

Conclusion

CEP55 is a useful predicator to improve stratification of patients with stage I pulmonary adenocarcinoma.

The Discovery of Novel Biomarkers Improves Breast Cancer Intrinsic Subtype Prediction and Reconciles the Labels in the METABRIC Data Set

BACKGROUND

The prediction of breast cancer intrinsic subtypes has been introduced as a valuable strategy to determine patient diagnosis and prognosis, and therapy response. The PAM50 method, based on the expression levels of 50 genes, uses a single sample predictor model to assign subtype labels to samples. Intrinsic errors reported within this assay demonstrate the challenge of identifying and understanding the breast cancer groups. In this study, we aim to: a) identify novel biomarkers for subtype individuation by exploring the competence of a newly proposed method named CM1 score, and b) apply an ensemble learning, as opposed to the use of a single classifier, for sample subtype assignment. The overarching objective is to improve class prediction.

METHODS AND FINDINGS

The microarray transcriptome data sets used in this study are: the METABRIC breast cancer data recorded for over 2000 patients, and the public integrated source from ROCK database with 1570 samples. We first computed the CM1 score to identify the probes with highly discriminative patterns of expression across samples of each intrinsic subtype. We further assessed the ability of 42 selected probes on assigning correct subtype labels using 24 different classifiers from the Weka software suite. For comparison, the same method was applied on the list of 50 genes from the PAM50 method.

CONCLUSIONS

The CM1 score portrayed 30 novel biomarkers for predicting breast cancer subtypes, with the confirmation of the role of 12 well-established genes. Intrinsic subtypes assigned using the CM1 list and the ensemble of classifiers are more consistent and homogeneous than the original PAM50 labels. The new subtypes show accurate distributions of current clinical markers ER, PR and HER2, and survival curves in the METABRIC and ROCK data sets. Remarkably, the paradoxical attribution of the original labels reinforces the limitations of employing a single sample classifiers to predict breast cancer intrinsic subtypes.

Beyond cytokinesis: the emerging roles of CEP55 in tumorigenesis

CEP55 was initially identified as a pivotal component of abscission, the final stage of cytokinesis, serving to regulate the physical separation of two daughter cells. Over the past 10 years, several studies have illuminated additional roles for CEP55 including regulating the PI3K/AKT pathway and midbody fate. Concurrently, CEP55 has been studied in the context of cancers including those of the breast, lung, colon and liver. CEP55 overexpression has been found to significantly correlate with tumor stage, aggressiveness, metastasis and poor prognosis across multiple tumor types and therefore has been included as part of several prognostic 'gene signatures' for cancer. Here by discussing in depth the functions of CEP55 across different effector pathways, and also its roles as a biomarker and driver of tumorigenesis, we assemble an exhaustive review, thus commemorating a decade of research on CEP55.