A pilot study of cdc6 as a biomarker for circulating tumor cells in patients with lung cancer

Integrated machine learning to predict the prognosis of lung adenocarcinoma patients based on SARS-COV-2 and lung adenocarcinoma crosstalk genes

Viruses are widely recognized to be intricately associated with both solid and hematological malignancies in humans. The primary goal of this research is to elucidate the interplay of genes between SARS-CoV-2 infection and lung adenocarcinoma (LUAD), with a preliminary investigation into their clinical significance and underlying molecular mechanisms. Transcriptome data for SARS-CoV-2 infection and LUAD were sourced from public databases. Differentially expressed genes (DEGs) associated with SARS-CoV-2 infection were identified and subsequently overlapped with TCGA-LUAD DEGs to discern the crosstalk genes (CGs). In addition, CGs pertaining to both diseases were further refined using LUAD TCGA and GEO datasets. Univariate Cox regression was conducted to identify genes associated with LUAD prognosis, and these genes were subsequently incorporated into the construction of a prognosis signature using 10 different machine learning algorithms. Additional investigations, including tumor mutation burden assessment, TME landscape, immunotherapy response assessment, as well as analysis of sensitivity to antitumor drugs, were also undertaken. We discovered the risk stratification based on the prognostic signature revealed that the low-risk group demonstrated superior clinical outcomes (p < 0.001). Gene set enrichment analysis results predominantly exhibited enrichment in pathways related to cell cycle. Our analyses also indicated that the low-risk group displayed elevated levels of infiltration by immunocytes (p < 0.001) and superior immunotherapy response (p < 0.001). In our study, we reveal a close association between CGs and the immune microenvironment of LUAD. This provides preliminary insight for further exploring the mechanism and interaction between the two diseases.

Exploring Bioinformatics Tools to Analyze the Role of CDC6 in the Progression of Polycystic Ovary Syndrome to Endometrial Cancer by Promoting Immune Infiltration

Cell division cycle 6 (CDC6) is essential for the initiation of DNA replication in eukaryotic cells and contributes to the development of various human tumors. Polycystic ovarian syndrome (PCOS) is a reproductive endocrine disease in women of childbearing age, with a significant risk of endometrial cancer (EC). However, the role of CDC6 in the progression of PCOS to EC is unclear. Therefore, we examined CDC6 expression in patients with PCOS and EC. We evaluated the relationship between CDC6 expression and its prognostic value, potential biological functions, and immune infiltrates in patients with EC. In vitro analyses were performed to investigate the effects of CDC6 knockdown on EC proliferation, migration, invasion, and apoptosis. CDC6 expression was significantly upregulated in patients with PCOS and EC. Moreover, this protein caused EC by promoting the aberrant infiltration of macrophages into the immune microenvironment in patients with PCOS. A functional enrichment analysis revealed that CDC6 exerted its pro-cancer and pro-immune cell infiltration functions via the PI3K-AKT pathway. Moreover, it promoted EC proliferation, migration, and invasion but inhibited apoptosis. This protein significantly reduced EC survival when mutated. These findings demonstrate that CDC6 regulates the progression of PCOS to EC and promotes immune infiltration.

LINC01088/miR-22/CDC6 Axis Regulates Prostate Cancer Progression by Activating the PI3K/AKT Pathway

Background

Prostate cancer (PCa) harms the male reproductive system, and lncRNA may play an important role in it. Here, we report that the LINC01088/microRNA- (miRNA/miR-) 22/cell division cycle 6 (CDC6) axis regulated through the phosphatidylinositide 3-kinases- (PI3K-) protein kinase B (AKT) signaling pathway controls the development of PCa.

Methods

lncRNA/miRNA/mRNA associated with PCa was downloaded and analyzed by Gene Expression Omnibus. The expression and correlation of LINC01088/miR-22/CDC6 in PCa were analyzed and verified by RT-qPCR. Dual-luciferase was used to analyze the binding between miR-22 and LINC01088 or CDC6. Cell Counting Kit-8 and Transwell were used to analyze the effects of LINC01088/miR-22/CDC6 interactions on PCa cell viability or migration/invasion ability. Localization of LINC01088 in cells was analyzed by nuclear cytoplasmic separation. The effect of LINC01088/miR-22/CDC6 interaction on downstream PI3K/AKT signaling was analyzed by Western blot.

Results

LINC01088 or CDC6 was upregulated in prostate tumor tissues or cells, whereas miR-22 was downregulated, miR-22 directly targets both LINC01088 and CDC6. si-LINC01088 inhibits the PCa process by suppressing the PI3K/AKT pathway. CDC6 reverses si-linc01088-mediated cell growth inhibition and reduction of PI3K and AKT protein levels.

Conclusion

Our results demonstrate that the LINC01088/miR-22/CDC6 axis functions in PCa progression and provide a promising diagnostic and therapeutic target.

Plasma Extracellular Vesicle Long RNA in Diagnosis and Prediction in Small Cell Lung Cancer

(1) Introduction: The aim of this study was to identify the plasma extracellular vesicle (EV)-specific transcriptional profile in small-cell lung cancer (SCLC) and to explore the application value of plasma EV long RNA (exLR) in SCLC treatment prediction and diagnosis. (2) Methods: Plasma samples were collected from 57 SCLC treatment-naive patients, 104 non-small-cell lung cancer (NSCLC) patients and 59 healthy participants. The SCLC patients were divided into chemo-sensitive and chemo-refractory groups based on the therapeutic effects. The exLR profiles of the plasma samples were analyzed by high-throughput sequencing. Bioinformatics approaches were used to investigate the differentially expressed exLRs and their biofunctions. Finally, a t-signature was constructed using logistic regression for SCLC treatment prediction and diagnosis. (3) Results: We obtained 220 plasma exLRs profiles in all the participants. Totals of 5787 and 1207 differentially expressed exLRs were identified between SCLC/healthy controls, between the chemo-sensitive/chemo-refractory groups, respectively. Furthermore, we constructed a t-signature that comprised ten exLRs, including EPCAM, CCNE2, CDC6, KRT8, LAMB1, CALB2, STMN1, UCHL1, HOXB7 and CDCA7, for SCLC treatment prediction and diagnosis. The exLR t-score effectively distinguished the chemo-sensitive from the chemo-refractory group (p = 9.268 × 10^-9) with an area under the receiver operating characteristic curve (AUC) of 0.9091 (95% CI: 0.837 to 0.9811) and distinguished SCLC from healthy controls (AUC: 0.9643; 95% CI: 0.9256-1) and NSCLC (AUC: 0.721; 95% CI: 0.6384-0.8036). (4) Conclusions: This study firstly characterized the plasma exLR profiles of SCLC patients and verified the feasibility and value of identifying biomarkers based on exLR profiles in SCLC diagnosis and treatment prediction.

CDC6 is a possible biomarker for hepatocellular carcinoma

OBJECTIVE

Research has proven that the expression of CDC6 is tightly related to tumorigenesis and progression of various tumors. However, the effects of CDC6 in hepatocellular carcinoma remain uncertain. The main purpose of this research is to explore this relationship.

METHODS

We assessed the expression levels of CDC6 in a serious of cancers from GEPIA database. The expression of CDC6 in hepatocellular carcinoma tissue and normal liver tissue was compared, and further assessed by immunohistochemical staining. Graphpad software was performed for data analysis, and t-test and χ² analysis were used to investigate the role of CDC6 in hepatocellular carcinoma.

RESULTS

The expression level of CDC6 was significantly higher in malignant carcinoid, melanoma, urothelial tumor, and hepatocellular carcinoma in the GEPIA online database. It was related to clinical progression of hepatocellular carcinoma. We found that the expression of CDC6 was correlated with tumor size (P=0.018) and the number of tumor nodes (P=0.003), but not with age, gender and AFP value (P>0.05).

CONCLUSIONS

The expression level of CDC6 in hepatocellular carcinoma is related tightly to clinical findings. Detecting the expression of CDC6 might provide a new biomarker for patients with hepatocellular carcinoma.

Increased CDC6 Expression Associates With Poor Prognosis in Patients With Clear Cell Renal Cell Carcinoma

Background

CDC6 (Cell division control protein 6), located at chromosome 17q21.3, plays an important role in the early stage of DNA replication and has unique functions in various malignant tumors. Here, we evaluate the relationship between CDC6 expression and oncology outcomes in patients with clear cell renal cell carcinoma (ccRCC).

Methods

A retrospective analysis of 118 ccRCC patients in Affiliated Hospital of Nantong University from 2015 to 2017 was performed. Triplicate tissue microarrays (TMA) were prepared from formalin-fixed and paraffin-embedded specimens. Immunohistochemistry (IHC) was conducted to evaluate the relationship between CDC6 expression and standard pathological features and prognosis. The RNA sequencing data and corresponding clinical information were acquired from the TCGA database. GSEA was used to identify signal pathways related to CDC6. Cox regression analysis was used to assess independent prognostic factors. In addition, the relationship between CDC6 and immunity was also investigated.

Results

The results of Kaplan–Meier curve indicated that the OS of the patients with high expression of CDC6 was shorter than that of the patients with low CDC6 expression. Integrating the TCGA database and IHC staining, the results showed that CDC6 in ccRCC tissue was obviously up-regulated compared with adjacent normal kidney tissue. The results of Logistic regression analysis demonstrated that ccRCC patients with high expression of CDC6 are more likely to develop advanced disease than ccRCC patients with low CDC6 expression. The results of GSEA showed that the high expression of CDC6 was related to multiple signaling pathways. As for immunity, it was also related to TMB, immune checkpoint molecules, tumor microenvironment and immune infiltration. There were significantly correlations with CDC6 and immune cell infiltration levels and tumor microenvironment. The results of further results of the TCGA database showed that CDC6 was obviously related to immune checkpoint molecules and immune cells.

Conclusions

Increased expression of CDC6 is a potentially prognostic factor of poor prognosis in ccRCC patients.

Diagnostic and prognostic role of liquid biopsy in non-small cell lung cancer: evaluation of circulating biomarkers

Lung cancer is still one of the main causes of cancer-related death, together with prostate and colorectal cancers in males and breast and colorectal cancers in females. The prognosis for non-small cell lung cancer (NSCLC) is strictly dependent on feasibility of a complete surgical resection of the tumor at diagnosis. Since surgery is indicated only in early stages tumors, it is necessary to anticipate the timing of diagnosis in clinical practice. In the diagnostic and therapeutic pathway for NSCLC, sampling of neoplastic tissue is usually obtained using invasive methods that are not free from disadvantages and complications. A valid alternative to the standard biopsy is the liquid biopsy (LB), that is, the analysis of samples from peripheral blood, urine, and other biological fluids, with a simple and non-invasive collection. In particular, it is possible to detect in the blood different tumor derivatives, such as cell-free DNA (cfDNA) with its subtype circulating tumor DNA (ctDNA), cell-free RNA (cfRNA), and circulating tumor cells (CTCs). Plasma-based testing seems to have several advantages over tumor tissue biopsy; firstly, it reduces medical costs, risk of complications related to invasive procedures, and turnaround times; moreover, the analysis of genes alteration, such as EGFR, ALK, ROS1, and BRAF is faster and safer with this method, compared to tissue biopsy. Despite all these advantages, the evidences in literatures indicate that assays performed on liquid biopsies have a low sensitivity, making them unsuitable for screening in lung cancer at the current state. This is caused by lack of standardization in sampling and preparation of specimen and by the low concentration of biomarkers in the bloodstream. Instead, routinely use of LB should be preferred in revaluation of patients with advanced NSCLC resistant to chemotherapy, due to onset of new mutations.

Long-Noncoding RNA CASC9 Promotes Progression of Non-Small Cell Lung Cancer by Promoting the Expression of CDC6 Through Binding to HuR

OBJECTIVE

The long-noncoding RNAs (lncRNAs) have been identified as key players in diverse cellular processes in non-small cell lung cancer (NSCLC). However, the understanding of biological functions and detailed mechanisms of lncRNAs is still limited. Herein, the lncRNA cancer susceptibility candidate 9 (CASC9) on NSCLC progression is investigated.

MATERIALS AND METHODS

Expressions of CASC9, HuR and cell division cycle 6 (CDC6) in NSCLC tissues were detected with quantitative real-time polymerase chain reaction (qRT-PCR). The cell counting kit-8, transwell assays, and flow cytometry were used to examine cell proliferation, migration, and the cell cycle. Tumor growth in vivo was evaluated by xenograft tumor experiments and immunohistochemistry. RNA-binding protein immunoprecipitation (RIP) was used to identify the interaction between HuR and CDC6, and CASC9 and HuR.

RESULTS

CASC9, CDC6 and HuR expression were found significantly upregulated in NSCLC tissues, which predicted poorer 5-year overall survival in NSCLC patients. Inhibition of CASC9 significantly reduced the malignancy of NSCLC cells, such as proliferation, migration and cell cycle. In vivo experiments further demonstrated that CASC9 knockdown reduced the tumor growth and the Ki-67 expression. Moreover, CASC9 knockdown inhibited the expression of CDC6 which was detected overexpressed in NSCLC tumor tissues. Then, up-regulation of CDC6 could partly reverse the negative effects of CASC9 on cell proliferation, migration and cell cycle. RIP assay and rescue experiment showed that CASC9 regulated CDC via binding to HuR.

CONCLUSION

Our results indicate that CASC9 conferred an aggressive phenotype in NSCLC and might be a pivotal target for this disease.

A pilot study of cdc6 as a biomarker for circulating tumor cells in patients with lung cancer

BACKGROUND

Cell division cycle 6 (cdc6) is a key factor of DNA replication initiation license system and a proto-oncogene. It has been detected in some tumor tissues to aid cancer diagnosis in many research projects. However, it remains unclear that if cdc6 could be detected in the peripheral blood, just like liquid biopsy, in solid tumor patients. The aim of this study is to investigate the possibility of cdc6 as a biomarker for circulating tumor cells in patients with lung cancer.

METHODS

We first detected the expression of cdc6 in peripheral blood mononuclear cells (PBMCs) and tumor cells by in situ hybridization with cdc6 RNA probe. Then, we examined the expression of cdc6 in PBMCs from health individual, mononuclear cells from cord blood, or A549 cell line by RT-qPCR. Furthermore, we used RT-qPCR to test the cdc6 expression in PBMCs from tumor patients (test group) and non-tumor individuals as a control group. Chi-square test with Fisher's exact test was used to analyze the statistical significance of the difference. P < .05 is considered as statistically significant difference.

RESULTS

When compared the cdc6 expression in cells from difference sources, we found that A549 tumor cell line had the strongest expression of cdc6, samples from cord blood showed the least expression level, indicating the detection strategy of RT-qPCR is reasonable. Using this method, we studied whether cdc6 in Peripheral blood could be detected as a biomarker by examining cdc6 expression from PBMCs of patients with lung cancer. We found 20% of patients with lung cancer were cdc6 positive in PBMCs, whereas only 4.26% was found positive in the control group (P = .039, P < .05).

CONCLUSION

Cell division cycle 6 has a potential to be used as a circulating tumor cell biomarker for lung cancer. Further study in clinical application is still broad needed.