MCM3 could be a better marker than Ki-67 for evaluation of dysplastic oral lesions: an immunohistochemical study

Identification of the role of MCM6 in bladder cancer prognosis, immunotherapy response, and in vitro experimental investigation using multi-omics analysis

BACKGROUND

The tumor-promoting effects of MCM6 in numerous tumors have been widely revealed, yet its specific role in bladder cancer (BLCA) is still elusive. The objective of this research was to explore the underlying impact of MCM6 on BLCA.

METHODS

Integrating transcriptomic and proteomic data, MCM6 was identified to be strongly correlated with BLCA through weighted gene co-expression network analysis(WGCNA) and venn analyses. Then, the clinical value of MCM6 was validated with public database data. The different molecular/immune characteristics and the benefit of immunotherapy were also found in MCM6-defined subgroups. Additionally, single-cell RNA sequencing (scRNA-seq) data was choose for quantify MCM6 expression in the distinct BLCA cell types. The biological role of MCM6 were evaluated via in vitro functional experiments.

RESULTS

It was testified that the MCM6 could distinguish patients outcome in TCGA and GEO cohorts. Moreover, compared with the MCM6 low-expression group, the MCM6 high-expression group was related to more tumor-promoting related pathways, aggressive phenotypes, and benefit from immunotherapy. Analysis of scRNA-seq data resulted in MCM6 was mainly expressed in BLCA epithelial cells and the proportion of MCM6-expressing tumor epithelial cells is higher than the normal epithelial cells. Moreover, vitro experiments demonstrated that MCM6 knockdown repressed proliferation, cell cycle, migration, and invasion of BLCA cells.

CONCLUSION

This research indicated MCM6 is a promising marker for both prognosis and immunotherapy benefit and could promote the cells proliferation, invasion and migration in BLCA.

Biomarkers of malignant transformation in oral leukoplakia: from bench to bedside

Oral leukoplakia is a common precursor lesion of oral squamous cell carcinoma, which indicates a high potential of malignancy. The malignant transformation of oral leukoplakia seriously affects patient survival and quality of life; however, it is difficult to identify oral leukoplakia patients who will develop carcinoma because no biomarker exists to predict malignant transformation for effective clinical management. As a major problem in the field of head and neck pathologies, it is imperative to identify biomarkers of malignant transformation in oral leukoplakia. In this review, we discuss the potential biomarkers of malignant transformation reported in the literature and explore the translational probabilities from bench to bedside. Although no single biomarker has yet been applied in the clinical setting, profiling for genomic instability might be a promising adjunct.

A meta-analysis reveals the protein profile associated with malignant transformation of oral leukoplakia

The search for biomarkers associated with oral leukoplakia malignant transformation is critical for early diagnosis and improved prognosis of oral cancer patients. This systematic review and meta-analysis aimed to assess protein-based markers potentially associated with malignant transformation of oral leukoplakia. Five database and the grey literature were searched. In total, 142 studies were included for qualitative synthesis, where 173 proteins were investigated due to their potential role in malignant progression from oral leukoplakia (OL) to oral squamous cell carcinoma (OSCC). The abundance of these proteins was analyzed in fixed tissues and/or biofluid samples, mainly by immunohistochemistry and ELISA, and 12 were shared by both samples. Enrichment analysis revealed that the differential abundant proteins are mostly involved with regulation of cell death, regulation of cell proliferation, and regulation of apoptotic process. Also, these proteins are mainly expressed in the extracellular region (55.5%), cell surface (24.8%), and vesicles (49.1%). The meta-analysis revealed that the proteins related to tumor progression, PD-L1, Mdm2, and Mucin-4 were significantly associated with greater abundance in OSCC patients, with an Odds Ratio (OR) of 0.12 (95% CI: 0.04-0.40), 0.44 (95% CI: 0.24-0.81), and 0.18 (95% CI: 0.04-0.86), respectively, with a moderate certainty of evidence. The results indicate a set of proteins that have been investigated across OSCC initiation and progression, and whose transcriptional expression is associated with clinical characteristics relevant to the prognosis and aggressiveness. Further verification and validation of this biomarkers set are strongly recommended for future clinical application.

Comparative proteoinformatics revealed the essentials of SDS impact on HaCaT keratinocytes

There is no direct evidence supporting that SDS is a carcinogen, so to investigate this fact, we used HaCaT keratinocytes as a model of human epidermal cells. To reveal the candidate proteins and/or pathways characterizing the SDS impact on HaCaT, we proposed comparative proteoinformatics pipeline. For protein extraction, the performance of two sample preparation protocols was assessed: 0.2% SDS-based solubilization combined with the 1DE-gel concentration (Protocol 1) and osmotic shock (Protocol 2). As a result, in SDS-exposed HaCaT cells, Protocol 1 revealed 54 differentially expressed proteins (DEPs) involved in the disease of cellular proliferation (DOID:14566), whereas Protocol 2 found 45 DEPs of the same disease ID. The 'skin cancer' term was a single significant COSMIC term for Protocol 1 DEPs, including those involved in double-strand break repair pathway (BIR, GO:0000727). Considerable upregulation of BIR-associated proteins MCM3, MCM6, and MCM7 was detected. The eightfold increase in MCM6 level was verified by reverse transcription qPCR. Thus, Protocol 1 demonstrated high effectiveness in terms of the total number and sensitivity of MS identifications in HaCaT cell line proteomic analysis. The utility of Protocol 1 was confirmed by the revealed upregulation of cancer-associated MCM6 in HaCaT keratinocytes induced by non-toxic concentration of SDS. Data are available via ProteomeXchange with identifier PXD035202.

Inter‑component immunohistochemical assessment of proliferative markers in uterine carcinosarcoma

In the scientific literature, a selected number of reports have investigated the impact of proliferative activity on the development and progression of uterine carcinosarcomas (UC). The aim of the present retrospective study was to compare the immunohistochemical proliferation markers [Ki67, proliferating cell nuclear antigen (PCNA), minichromosome maintenance complex component 3 (MCM3), and topoisomerase IIα (topoIIα)] assessment in both components of UC. A total of 30 paraffin-embedded slides of UCs, obtained from patients who underwent surgery between January 1, 2006, and December 31, 2020, were analyzed. Medical records and clinicopathological data of patients were reviewed. Formalin-fixed, paraffin-embedded tissue sections were immunostained with monoclonal antibodies against Ki67, PCNA, MCM3 and topoIIα. Ki67-positive nuclear immunoreactivity was reported in 20 (67%) and 16 (53%) UC carcinomatous and sarcomatous components, respectively. In the epithelial component, Ki67 positive staining was related to the International Federation of Gynecology and Obstetrics (FIGO) stage (P=0.025), and histological grade (G1 vs. G2/G3, P=0.031). Nuclear PCNA reactivity was observed in 18 (60%) and 16 (53%) carcinomatous and sarcomatous components, respectively. Notably, all four cases with omental metastases were PCNA-positive, and a relationship between staining pattern and the existence of metastases was of significant value (P=0.018). MCM3-positive nuclear staining was found nearly twice as high in the carcinomatous (n=19; 63%), compared with the sarcomatous (n=11; 37%) component, respectively, and MCM3 expression in the epithelial component was related to clinical stage (P=0.030), and the existence of omental metastasis (P=0.012). In addition, out of the 30 UCs, 17 (57%) and 13 (43%) showed topoIIα positivity in the carcinomatous and sarcomatous UC components, respectively. A significant relationship between protein immunoreactivity and FIGO stage (P=0.049), and omental metastasis (P=0.026) was revealed to exist. However, no significant differences between expression of proliferation markers and clinicopathological features in the sarcomatous UC component were identified. Finally, a significant correlation between each protein immunohistochemical staining was demonstrated, particularly in the sarcomatous UC component. Collectively, a combined analysis of Ki67, PCNA, MCM3, and topoIIα may provide more detailed information of cell-cycle alterations determining the heterogeneity of uterine carcinosarcomas.

MCM3 is a novel proliferation marker associated with longer survival for patients with tubo-ovarian high-grade serous carcinoma

Tubo-ovarian high-grade serous carcinomas (HGSC) are highly proliferative neoplasms that generally respond well to platinum/taxane chemotherapy. We recently identified minichromosome maintenance complex component 3 (MCM3), which is involved in the initiation of DNA replication and proliferation, as a favorable prognostic marker in HGSC. Our objective was to further validate whether MCM3 mRNA expression and possibly MCM3 protein levels are associated with survival in patients with HGSC. MCM3 mRNA expression was measured using NanoString expression profiling on formalin-fixed and paraffin-embedded tissue (N = 2355 HGSC) and MCM3 protein expression was assessed by immunohistochemistry (N = 522 HGSC) and compared with Ki-67. Kaplan-Meier curves and the Cox proportional hazards model were used to estimate associations with survival. Among chemotherapy-naïve HGSC, higher MCM3 mRNA expression (one standard deviation increase in the score) was associated with longer overall survival (HR = 0.87, 95% CI 0.81-0.92, p < 0.0001, N = 1840) in multivariable analysis. MCM3 mRNA expression was highest in the HGSC C5.PRO molecular subtype, although no interaction was observed between MCM3, survival and molecular subtypes. MCM3 and Ki-67 protein levels were significantly lower after exposure to neoadjuvant chemotherapy compared to chemotherapy-naïve tumors: 37.0% versus 46.4% and 22.9% versus 34.2%, respectively. Among chemotherapy-naïve HGSC, high MCM3 protein levels were also associated with significantly longer disease-specific survival (HR = 0.52, 95% CI 0.36-0.74, p = 0.0003, N = 392) compared to cases with low MCM3 protein levels in multivariable analysis. MCM3 immunohistochemistry is a promising surrogate marker of proliferation in HGSC.

The DNA replication regulator MCM6: An emerging cancer biomarker and target

MCM6 is a significant DNA replication regulator that plays a crucial role in sustaining the cell cycle. In many cancer cells, MCM6 expression is enhanced. For example, persistently increased expression of MCM6 promotes the formation, development and progression of hepatocellular carcinoma (HCC). Up- and down-regulation studies have indicated that MCM6 regulates cell cycle, proliferation, metastasis, immune response and the maintenance of the DNA replication system. MCM6 can also regulate downstream signaling such as MEK/ERK thus promoting carcinogenesis. Accordingly, MCM6 may represent a sensitive and specific biomarker to predict adverse progression and poor outcome. Furthermore, inhibition of MCM6 may be an effective cancer treatment. The present review summarizes the latest results on the inactivating and activating functions of MCM6, underlining its function in carcinogenesis. Further studies of the carcinogenic functions of MCM6 may provide novel insight into cancer biology and shed light on new approaches for cancer diagnosis and treatment.

Expression Profile and Prognostic Values of Mini-Chromosome Maintenance Families (MCMs) in Breast Cancer

Background

Mini-chromosome maintenance families (MCMs) were considered the key factors for DNA replication initiation. Emerging evidences indicate that MCM2-7 (MCMs) are highly expressed in tissues from various malignant tumors. However, little is known about the clinical values of MCMs in breast cancer.

Material/Methods

In our study, a comprehensive bioinformatics analysis was performed to investigate expression patterns, potential functions, and prognostic values of MCMs in breast cancer, through ONCOMINE, bc-GenExMiner v4.1, Kaplan-Meier Plotter, cBioPortal and GeneMANIA databases.

Results

We found that mRNA levels of MCMs were significantly elevated in breast cancer, especially in fast-growing and spreading tumor subtypes. These over-expressed MCMs predicted worse prognosis for breast cancer patients with shorter relapse-free survival (RFS) and overall survival. Among these six factors, high expression of MCM2/4/5/7 significantly reduced the RFS for patients with Luminal-A or B breast cancer and elevated MCM6/7 indicated shorter RFS for patients with basal-like or HER2-positive breast cancer. We also found that genomic alteration of MCMs was frequently found in breast cancer and the most common alteration was mRNA upregulation and amplification. Furthermore, MCMs were highly correlated with CDC45, CDC7, TIMELESS, ORC6, MCM10, ORC5, ORC4 and ORC3, mainly functioning to control the DNA replication initiation and genome stability.

Conclusions

These results suggest that MCMs are attractive prognostic biomarkers for breast cancer. Our study also provides useful clinical information about the potential of MCMs as therapeutic targets.

Minichromosome Maintenance Complex (MCM) Genes Profiling and MCM2 Protein Expression in Cervical Cancer Development

OBJECTIVE

Minichromosome maintenance complex (MCM) proteins are essential for the process of DNA replication and cell division. This study aimed to evaluate MCM genes expression profiles and MCM2 protein in HPV-associated cervical carcinogenesis.

METHODOLOGY

MCM2, 4, 5 and 7 genes expression profiles were evaluated in three cervical tissue samples each of normal cervix, human papillomavirus (HPV)-infected low grade squamous intraepithelial lesion (LSIL), high grade squamous intraepithelial lesion (HSIL) and squamous cell carcinoma (SCC), using Human Transcriptome Array 2.0 and validated by nCounter® PanCancer Pathway NanoString Array. Immunohistochemical expression of MCM2 protein was semi-quantitatively assessed by histoscore in tissue microarrays containing 9 cases of normal cervix, 10 LSIL, 10 HSIL and 42 cases of SCC.

RESULTS

MCM2, 4, 5 and 7 genes expressions were upregulated with increasing fold change during the progression from LSIL to HSIL and the highest in SCC. MCM2 gene had the highest fold change in SCC compared to normal cervix. Immunohistochemically, MCM2 protein was localised in the nuclei of basal cells of normal cervical epithelium and dysplastic-neoplastic cells of CIN and SCC. There was a significant difference in MCM2 protein expression between the histological groups (P = 0.039), and histoscore was the highest in HSIL compared to normal cervix (P = 0.010).

CONCLUSION

The upregulation of MCM genes expressions in cervical carcinogenesis reaffirms MCM as a proliferative marker in DNA replication pathway, whereby proliferation of dysplastic and cancer cells become increasingly dysregulated and uncontrolled. A strong expression of MCM2 protein in HSIL may aid as a concatenated screening tool in detecting pre-cancerous cervical lesions.

Recent trends in predictive biomarkers for determining malignant potential of oral potentially malignant disorders

Despite of the tremendous advancements in the field of cancer prevention, detection and treatment, the overall prognosis of oral squamous cell carcinoma (OSCC) still remains poor. This can be partly imparted to the lack of early detection of oral potentially malignant disorders (OPMDs), especially those at a higher risk of progression into OSCC. Over years, various specific and non-specific markers have been introduced that could predict the malignant transformation of OPMDs; however detail information on these OPMD markers in a concise manner is lacking. Moreover, their use on daily clinical basis still remains questionable. With continuous research in the field of cytology and genomics, several contemporary biomarkers have been discovered that are not yet foregrounded and proved to be more promising than those used conventionally. Here, in the present paper, we overview several recently concluded predictive biomarkers with special emphasis on their role in molecular pathogenesis of OSCC transformation. These markers can be used for risk assessment of malignant transformation in patients with OPMDs as well as for prophylactic conciliation and fair management of the high-risk OPMD patient group.

DNA replication licensing proteins: Saints and sinners in cancer

DNA replication is all-or-none process in the cell, meaning, once the DNA replication begins it proceeds to completion. Hence, to achieve maximum control of DNA replication, eukaryotic cells employ a multi-subunit initiator protein complex known as "pre-replication complex or DNA replication licensing complex (DNA replication LC). This complex involves multiple proteins which are origin-recognition complex family proteins, cell division cycle-6, chromatin licensing and DNA replication factor 1, and minichromosome maintenance family proteins. Higher-expression of DNA replication LC proteins appears to be an early event during development of cancer since it has been a common hallmark observed in a wide variety of cancers such as oesophageal, laryngeal, pulmonary, mammary, colorectal, renal, urothelial etc. However, the exact mechanisms leading to the abnormally high expression of DNA replication LC have not been clearly deciphered. Increased expression of DNA replication LC leads to licensing and/or firing of multiple origins thereby inducing replication stress and genomic instability. Therapeutic approaches where the reduction in the activity of DNA replication LC was achieved either by siRNA or shRNA techniques, have shown increased sensitivity of cancer cell lines towards the anti-cancer drugs such as cisplatin, 5-Fluorouracil, hydroxyurea etc. Thus, the expression level of DNA replication LC within the cell determines a cell's fate thereby creating a paradox where DNA replication LC acts as both "Saint" and "Sinner". With a potential to increase sensitivity to chemotherapy drugs, DNA replication LC proteins have prospective clinical importance in fighting cancer. Hence, in this review, we will shed light on importance of DNA replication LC with an aim to use DNA replication LC in diagnosis and prognosis of cancer in patients as well as possible therapeutic targets for cancer therapy.

MCM3 and Ki67 proliferation markers in odontogenic cysts and ameloblastoma

Background

MCM3 is a marker of proliferation that has been used as a diagnostic or prognostic marker in many pathologic lesions.

Purpose

The purpose of this study is to investigate the proliferative activity of dentigerous cysts, odontogenic keratocyst and ameloblastoma using minichromosome maintenance 3 (MCM3) and compare it with Ki-67 proliferation marker.

Methods

In this cross-sectional study, 40 cases including 11 cases of dentigerous cyst, 14 odontogenic keratocyst, and 15 ameloblastoma were included. Immunohistochemical expression of MCM3 and Ki-67 were investigated and compared statistically using ANOVA, Chi-square, Tukey and Spearman's correlation tests.

Results

All subjects were positive for Ki-67 and MCM3. There was a significant difference in MCM3 and Ki-67 expression among all groups. Compared to Ki-67, MCM3 exhibited a higher level of expression. Ameloblastoma and odontogenic keratocyst revealed higher expression rate of both markers in comparison to dentigerous cysts.

Conclusion

The results showed MCM3 and Ki67 expression in the most common odontogenic cysts and tumors, especially more aggressive lesions. MCM3 might have a role in pathogenesis of these lesions and could be a reliable marker for assessing proliferation activity.

MCM3: A Novel Proliferation Marker in Oral Squamous Cell Carcinoma

The present study sought to evaluate and compare the immunoexpression of proteins minichromosome maintenance (MCM) 3 and Ki-67 in oral squamous cell carcinoma (OSCC) to assess the potential of these proteins as markers of cellular proliferation. Twenty-eight cases of OSCC, 9 of tumor-free resection margins (TM), and 4 of non-neoplastic oral mucosa (NNM) were subjected to immunohistochemistry to detect the expression of proteins MCM3 and Ki-67. All OSCCs demonstrated positivity for both proteins. In these tumors, greater MCM3 immunoreactivity was observed in comparison with Ki-67, whereas TMs and NNMs exhibited greater Ki-67 expression compared with MCM3. The immunoexpression of Ki-67 seemed to be influenced by the inflammatory process, particularly in TM and NNM. Our findings indicate that although both MCM3 and Ki-67 represent reliable markers of cellular proliferation in OSCC, as MCM3 expression does not appear to be influenced by external factors, this protein may emerge as a novel marker of cellular proliferation in these types of tumors.

MCM family in HCC: MCM6 indicates adverse tumor features and poor outcomes and promotes S/G2 cell cycle progression

Background

Minichromosome Maintenance family (MCMs), as replication licensing factors, is involved in the pathogenesis of tumors. Here, we investigated the expression of MCMs and their values in hepatocellular carcinoma (HCC).

Methods

MCMs were analyzed in 105 samples including normal livers (n = 15), cirrhotic livers (n = 40), HCC (n = 50) using quantitative polymerase chain reaction (qPCR) (Cohort 1). Significantly up-regulated MCMs were verified in 102 HCC and matched peritumoral livers using PCR (Cohort 2), and the correlations with clinical features and outcomes were determined. In addition, the focused MCMs were analyzed in parallel immunohistochemistry of 345 samples on spectrum of hepatocarcinogenesis (Cohort 3) and queried for the potential specific role in cell cycle.

Results

MCM2–7, MCM8 and MCM10 was significantly up-regulated in HCC in Cohort 1. In Cohort 2, overexpression of MCM2–7, MCM8 and MCM10 was verified and significantly correlated with each other. Elevated MCM2, MCM6 and MCM7 were associated with adverse tumor features and poorer outcomes. In Cohort 3, MCM6 exhibited superior HCC diagnostic performance compared with MCM2 and MCM7 (AUC: 0.896 vs. 0.675 and 0.771, P < 0.01). Additionally, MCM6 other than MCM2 and MCM7 independently predicted poorer survival in 175 HCC patients. Furthermore, knockdown of MCM6 caused a delay in S/G2-phase progression as evidenced by down-regulation of CDK2, CDK4, CyclinA, CyclinB1, CyclinD1, and CyclinE in HCC cells.

Conclusions

We analyze MCMs mRNA and protein levels in tissue samples during hepatocarcinogenesis. MCM6 is identified as a driver of S/G2 cell cycle progression and a potential diagnostic and prognostic marker in HCC.

Electronic supplementary material

The online version of this article (10.1186/s12885-018-4056-8) contains supplementary material, which is available to authorized users.

Ki-67 protein predicts survival in oral squamous carcinoma cells: an immunohistochemical study

The aim of this study was to identify the expression of Ki-67 and MCM3 in oral squamous cell carcinoma (OSCC) as well as to address the correlation with patient survival and clinical features. Samples were collected from 51 patients with OSCC who presented for follow-up. Immunohistochemical expression of Ki-67 and MCM3 in all groups was performed. The scoring system was previous published by Tsurutani in 2005. We used Kappa index to evaluate observers agreement degree. The associations between protein expression and clinical variables were examined for statistical significance using the chi-squared test. The overall survival rates were estimated by the Kaplan-Meier method and the relationship between protein expression and survival was compared using the log-rank test (p < 0.05). The overall survival time for a patient with positive immunostaining for Ki-67 is shorter than for a patient with negative immunostaining, (log-rank test, p = 0.00882). Patients with tumor size T3 and T4 showed a statistically significant relationship with Ki-67 immunoexpression (log-rank test, p = 0.0174). The relationship between Ki-67 expression and the relation between age, gender, smoking, tumor site, lymph node metastasis and disease stage was not significant. The examiners agreement degree by Kappa presented p value < 0.05. There was not a significant correlation when we evaluated MCM3 expression regarding clinical characteristics and survival rate. From these results, the present study suggests that positive Ki-67 expression found in OSCC patients may contribute to predict the survival in OSCC samples, as well as the relation between the protein and the tumor size.

Immunoexpression of Ki-67, MCM2, and MCM3 in Ameloblastoma and Ameloblastic Carcinoma and Their Correlations with Clinical and Histopathological Patterns

Cell proliferation assays are performed using antibodies against nuclear proteins associated with DNA replication. These nuclear proteins have gained special interest to predict the biological and clinical behaviors of various tumors. The aim of this study was to analyze the presence of Ki-67 protein and the minichromosome maintenance-2 (MCM2) and maintenance-3 (MCM3) proteins in ameloblastoma. Materials and Methods. Cell proliferation marker expression levels were assessed via immunohistochemistry in 111 ameloblastoma cases (72 unicystic ameloblastoma samples, 38 solid/multicystic ameloblastoma samples, and 1 ameloblastic carcinoma). The label index was performed as described previously. Results. MCM2 and MCM3 showed higher proliferation indexes in all variants of ameloblastoma compared to the classic marker Ki-67. No correlation between the proliferation index and the clinical and protein expression data was observed. Conclusion. The results suggest that clinical features do not directly affect tumor cell proliferation. Moreover, the high levels of cellular proliferation of MCM2 and MCM3 compared with Ki-67 may indicate that MCM2 and MCM3 are more sensitive markers for predicting the growth rate and eventually might be helpful as a tool for predicting aggressive and recurrent behaviors in these tumors.