Expression of metastasis suppressor gene (KAI1/CD82) in oral squamous cell carcinoma and its clinico-pathological significance

Tetraspanin CD82 Correlates with and May Regulate S100A7 Expression in Oral Cancer

Many metastatic cancers with poor prognoses correlate to downregulated CD82, but exceptions exist. Understanding the context of this correlation is essential to CD82 as a prognostic biomarker and therapeutic target. Oral squamous cell carcinoma (OSCC) constitutes over 90% of oral cancer. We aimed to uncover the function and mechanism of CD82 in OSCC. We investigated CD82 in human OSCC cell lines, tissues, and healthy controls using the CRISPR-Cas9 gene knockout, transcriptomics, proteomics, etc. CD82 expression is elevated in CAL 27 cells. Knockout CD82 altered over 300 genes and proteins and inhibited cell migration. Furthermore, CD82 expression correlates with S100 proteins in CAL 27, CD82KO, SCC-25, and S-G cells and some OSCC tissues. The 37-50 kDa CD82 protein in CAL 27 cells is upregulated, glycosylated, and truncated. CD82 correlates with S100 proteins and may regulate their expression and cell migration. The truncated CD82 explains the invasive metastasis and poor outcome of the CAL 27 donor. OSCC with upregulated truncated CD82 and S100A7 may represent a distinct subtype with a poor prognosis. Differing alternatives from wild-type CD82 may elucidate the contradictory functions and pave the way for CD82 as a prognostic biomarker and therapeutic target.

Prognostic role of CD82/KAI1 in multiple human malignant neoplasms: a meta-analysis of 31 studies

Tetraspanin CD82, also known as KAI1, was revealed as an attractive prognostic tumor biomarker in recent studies. However, some results of these studies remained debatable and inconclusive. Therefore, we conducted a meta-analysis to clarify the precise predictive value of CD82 in various neoplasms. Qualified studies were identified up to April 27, 2017, by searching PubMed, EMBASE, and the Web of Science. In total, 29 eligible studies were ultimately enrolled in this meta-analysis. Pooled hazard ratios (HRs) with 95% CIs of overall survival and disease/recurrence/progression-free survival were calculated to evaluate the correct prognostic role of CD82. Statistical analysis demonstrated that high expression of CD82 was significantly associated with enhanced overall survival (HR =0.56, 95% CI: 0.47–0.67) and disease/recurrence/progression-free survival (HR =0.42, 95% CI: 0.30–0.59) in cancer patients. Furthermore, we also conducted the subgroup analysis and the results revealed that CD82 was associated with favorable outcomes in cancer patients. Taken together, CD82 could be a promising biomarker for predicting the prognosis of patients with malignant neoplasms, and the biological functions of CD82 are of great research value of the subject.

Roles of KAI1 and nm23 in lymphangiogenesis and lymph metastasis of laryngeal squamous cell carcinoma

Background

Lymphatic metastasis contributes to the poor prognosis of laryngeal squamous cell carcinoma (LSCC). This study aimed to investigate the roles of two metastasis suppressor genes, KAI1 and nm23, in lymphangiogenesis and lymph metastasis of LSCC.

Methods

A total of 45 LSCC patients were enrolled in this study. The positive expression rates of KAI1 and nm23 protein were detected via immunohistochemistry in 45 LSCC and 22 normal laryngeal mucosa adjacent to LSCC. Micro-lymphatic vessel density (MLVD) was detected via immunohistochemistry with the specific antibody D2-40. Associations between KAI1 and nm23 expression and clinical characteristics of LSCC were then evaluated.

Results

The positive expression rates of KAI1 and nm23 were significantly lower in LSCC than normal laryngeal mucosa (P < 0.05). Significantly lower positive rates of KAI1 and nm23 were found in LSCC with lymphatic metastasis than those without lymphatic metastasis (P < 0.05), whereas MLVD was negatively correlated with the expression of KAI1 and nm23 (P < 0.05). However, no significant associations were found between KAI1 and nm23 expression and clinical characteristics of LSCC (sex, age, disease position, differentiation, and T-stage).

Conclusions

Both KAI1 and nm23 can inhibit lymphangiogenesis and lymphatic metastasis in LSCC.

KAI-1 and p53 expression in oral squamous cell carcinomas: Markers of significance in future diagnostics and possibly therapeutics

CONTEXT

KAI-1/CD82 is a tumor suppressor gene with decreased gene expression being associated with increased invasive ability of oral squamous cell carcinomas (OSCCs). p53 protein functions in the G1-S phase of the cell cycle to allow repair of damaged DNA. In the present study, p53 and KAI-1 expression was investigated using monoclonal antibodies in OSCC.

AIMS

The aim of this study was to detect KAI-1 and p53 expression in OSCCs and to assess the relation between both in OSCCs.

MATERIALS AND METHODS

The present study included histopathologically diagnosed thirty cases of well- and moderately differentiated OSCCs to study the expression of KAI-1 and p53 antibodies.

STATISTICAL ANALYSIS

The results obtained were tabulated and statistically analyzed using descriptive statistical analysis; one-way ANOVA; least square difference method and independent t-test.

RESULTS

OSCCs exhibited 41.62% positivity for KAI-1 while p53 positive cells were recorded to an extent of 60.82%. A significant positive correlation was observed between KAI-1 and p53 expression in OSCCs.

CONCLUSIONS

Although a significant amount of work is still required to uncover the mechanisms of action and regulation of KAI-1 and p53 expression, control of the complex metastatic processes would be of interest in controlling the tumor biology in OSCCs as well as other types of malignancies to enhance prognosis in the affected patients and to help protect against future metastasis in the going to be treated and treated patients.

p12CDK2-AP1 interacts with CD82 to regulate the proliferation and survival of human oral squamous cell carcinoma cells

p12 cyclin-dependent kinase 2 (CDK2)-associating protein 1 (p12CDK2-AP1) has been demonstrated to negatively regulate the activity of CDK2. However, the underlying molecular mechanism remains largely unknown. We aimed to determine the potential binding proteins of p12CDK2-AP1 and to elucidate the role of p12CDK2-AP1 in the regulation of the proliferation, invasion, apoptosis, and in vivo growth of human oral squamous cell carcinoma cells. The protein-protein interaction was predicted using computational decision templates. The predicted p12CDK2‑AP1 interacting proteins were overexpressed in human oral squamous cell carcinoma OSCC-15 cells, and the protein binding was examined using co-precipitation (Co-IP). Cell proliferation and invasion were determined via MTT assay and Transwell system, respectively. Cell apoptosis was evaluated using Annexin V-FITC/PI double staining followed by flow cytometric analysis. The in vivo growth of OSCC-15 cells was examined in nude mouse tumor xenografts. We found that overexpression of either p12CDK2-AP1 or CD82 significantly suppressed the proliferation and invasion but promoted the apoptosis of OSCC-15 cells (P<0.05). Importantly, combined overexpression of p12CDK2-AP1 and CD82 showed synergistic antitumor activity compared with the overexpression of a single protein alone (P<0.05). Additionally, the simultaneous overexpression of p12CDK2-AP1 and CD82 significantly suppressed the in vivo tumor growth of OSCC-15 cells in nude mice compared with the negative control (P<0.05). Our findings indicate that p12CDK2-AP1 interacts with CD82 to play a functional role in suppressing the in vitro and in vivo growth of OSCC-15 cells.

Tetraspanins CD9 and CD151, epidermal growth factor receptor and cyclooxygenase-2 expression predict malignant progression in oral epithelial dysplasia

Background:

Prognostic biomarkers aim to improve on the current inadequate method of histological assessment to identify patients with oral epithelial dysplasia at greatest risk of malignant transformation. We aimed to assess the prognostic ability of six protein biomarkers linked to the epidermal growth factor receptor (EGFR) pathway, including three tetraspanins, in a large multicentre oral dysplasia cohort.

Methods:

One hundred and forty-eight cases with varying degrees of epithelial dysplasia underwent immunohistochemical assessment for CD9, CD151, CD82, EGFR, Her-2, and COX-2. Scoring was performed independently by two observers. Univariate analyses using both logistic and Cox regression models and a multivariate regression were performed.

Results:

Malignant progression was significantly greater in those cases with decreased expression of CD9 (P=0.02), and increased expression of CD151 (P=0.02), EGFR (P=0.04), and COX-2 (P=0.003). Histological grade (P=0.0002) and morphology (P=0.03) were also prognostic, whereas smoking and alcohol were not. The optimal combination by backward-variable selection was of histological grade (hazard ratio (HR) 1.64; 95% CI 1.12, 2.40), COX-2 overexpression (HR 1.12; 1.02, 1.24) and CD9 underexpression (HR 0.88; 0.80, 0.97). CD82 and Her-2 demonstrated no prognostic ability.

Conclusion:

This is the first study of the expression and prognostic potential of the tetraspanins in oral dysplasia. A combination of certain biomarkers with clinical factors appeared to improve the accuracy of determining the risk of malignancy in individuals with oral dysplasia. These findings may also offer potential new therapeutic approaches for this condition.

Downregulation of CD9 protein expression is associated with aggressive behavior of oral squamous cell carcinoma

Squamous cell carcinoma of the oral cavity (OSCC) is a malignancy characterized by a high degree of local aggression and metastasis to cervical lymph nodes. Tetraspanins are proteins with functional roles in a wide array of cellular processes and are reported to be associated with tumor progression. The present study investigated the expression of the CD9, CD37, CD63, CD81 and CD82 tetraspanins in OSCC using immunohistochemistry (IHC) and quantitative Real Time-PCR (qRT-PCR). Tissue microarray (TMA) analysis of samples from 179 cases of OSCC and 10 normal samples oral mucosa were evaluated immunomorphologically. We analyzed CD9 and CD82 expression by qRT-PCR in 66 OSCC cases and 4 normal samples of oral mucosa. Expression of CD63, CD37 and CD81 was not detected in the samples studied. CD82 was downregulated or negative in 127 of 179 (80%) specimens; no correlation was observed between CD82 expression, clinicopathological parameters, disease-free survival and 5-year overall survival. CD9 expression was downregulated or negative in 75 of 129 (42%) OSCC samples. Loss of CD9 expression in OSCC samples correlated with the incidence of lymph node metastasis (p=0.017). Disease-free survival and the 5-year overall survival of patients with downregulated or negative CD9 expression were significantly lower than in patients with positive CD9 expression (p=0.010 and p=0.071, respectively). No correlation was found between CD9 or CD82 expression and clinicopathological parameters by qRT-PCR. Our results suggest that the downregulation or lack of expression of the CD9 protein might indicate a more aggressive of OSCC.

KITENIN increases invasion and migration of mouse squamous cancer cells and promotes pulmonary metastasis in a mouse squamous tumor model

KAI1 C-terminal interacting tetraspanin (KITENIN) is reported to promote metastasis in mouse colon cancer models. We investigated the role of KITENIN on the progression of squamous cell carcinoma (SCC). In a preliminary clinical study using resected tissues from head and neck SCC patients, KITENIN was highly expressed in tumors and metastatic lymph nodes, while KAI1 was more increased in adjacent mucosa than in tumor. KITENIN-transfected mouse squamous cancer (SCC VII/KITENIN) cells showed significantly higher invasion, migration, and proliferation than empty vector-transfected cells. In syngeneic mouse squamous tumor models, more increased tumor volume and enhanced lung metastasis were found in SCC VII/KITENIN cells-injected mice. Thus, KITENIN increases invasion and migration of squamous cancer cells and thereby promotes distant metastasis in mouse squamous tumor models.

Overexpression of metastasis-associated MTA1 in oral squamous cell carcinomas: correlation with metastasis and invasion

Metastasis-associated protein 1 (MTA1) is physiologically expressed at low levels in human tissues. Its expression is associated with progression of solid cancers and is common in cancer cell lines. This study investigated whether MTA1 was expressed in squamous cell carcinoma (SCC) and would be a useful metastatic marker. Specimens from 38 patients with oral SCC were stained using the avidin-biotin-peroxidase technique with polyclonal antibodies against MTA1. Human SCC cell lines SAS, HSC2, OSC19 and OSC20 were analysed for MTA1 mRNA expression. MTA1 expression in control tissues was significantly lower than in carcinomas. MTA1 protein expression was detected in 33 of 38 SCC tissues from patients. Histologically, MTA1 protein production was strongly associated with cancer cell invasion, and clinically there was a correlation between lymph node metastasis and MTA1 protein production. Among the cancer cell lines, HSC2 showed the lowest mRNA expression, and OSC20 showed the highest MTA1 mRNA expression. In the Matrigel invasion assay, the HSC2 cell line showed the lowest invasion and the OSC20 cell line showed the highest invasion. RNAi-mediated MTA1 silencing in the OSC20 cells decreased the invasion index. MTA1 expression in oral SCC may be associated with increased invasive ability, which may cause lymph node metastasis.

Cancer stem cells as targets for cancer therapy: selected cancers as examples

It is becoming increasingly evident that cancer constitutes a group of diseases involving altered stem-cell maturation/differentiation and the disturbance of regenerative processes. The observed malignant transformation is merely a symptom of normal differentiation processes gone astray rather than the primary event. This review focuses on the role of cancer stem cells (CSCs) in three common but also relatively under-investigated cancers: head and neck, ovarian, and testicular cancer. For didactic purpose, the physiology of stem cells is first introduced using hematopoietic and mesenchymal stem cells as examples. This is followed by a discussion of the (possible) role of CSCs in head and neck, ovarian, and testicular cancer. Aside from basic information about the pathophysiology of these cancers, current research results focused on the discovery of molecular markers specific to these cancers are also discussed. The last part of the review is largely dedicated to signaling pathways active within various normal and CSC types (e.g. Nanog, Nestin, Notch1, Notch2, Oct3 and 4, Wnt). Different elements of these pathways are also discussed in the context of therapeutic opportunities for the development of targeted therapies aimed at CSCs. Finally, alternative targeted anticancer therapies arising from recently identified molecules with cancer-(semi-)selective capabilities (e.g. apoptin, Brevinin-2R) are considered.

Proteomics analysis of cells in whole saliva from oral cancer patients via value-added three-dimensional peptide fractionation and tandem mass spectrometry

Whole human saliva possesses tremendous potential in clinical diagnostics, particularly for conditions within the oral cavity such as oral cancer. Although many have studied the soluble fraction of whole saliva, few have taken advantage of the diagnostic potential of the cells present in saliva, and none have taken advantage of proteomics capabilities for their study. We report on a novel proteomics method with which we characterized for the first time cells contained in whole saliva from patients diagnosed with oral squamous cell carcinoma. Our method uses three dimensions of peptide fractionation, combining the following steps: preparative IEF using free flow electrophoresis, strong cation exchange step gradient chromatography, and microcapillary reverse-phase liquid chromatography. We determined that the whole saliva samples contained enough cells, mostly exfoliated epithelial cells, providing adequate amounts of total protein for proteomics analysis. From a mixture of four oral cancer patient samples, the analysis resulted in a catalogue of over 1000 human proteins, each identified from at least two peptides, including numerous proteins with a role in oral squamous cell carcinoma signaling and tumorigenesis pathways. Additionally proteins from over 30 different bacteria were identified, some of which putatively contribute to cancer development. The combination of preparative IEF followed by strong cation exchange chromatography effectively fractionated the complex peptide mixtures despite the closely related physiochemical peptide properties of these separations (pI and solution phase charge, respectively). Furthermore compared with our two-step method combining preparative IEF and reverse-phase liquid chromatography, our three-step method identified significantly more cellular proteins while retaining higher confidence protein identification enabled by peptide pI information gained through IEF. Thus, for detecting salivary markers of oral cancer and possibly other conditions of the oral cavity, the results confirm both the potential of analyzing the cells in whole saliva and doing so with our proteomics method.

Life-threatening disorders of mucous membranes

Oral mucosa is one of the first barriers to the outside world which encounters various antigens, microorganisms and physical agents. Numerous oral pathologies challenge the dermatologists. Some may be the first sign of an underlying immunosuppression, while others are the inevitable serious outcomes of long-lasting mucosal disease. The differential diagnosis is crucial in terms of prompt and effective treatment.

Down-regulation of KAI1/CD82 protein expression in oral cancer correlates with reduced disease free survival and overall patient survival

Oral Squamous Cell Carcinoma (OSCC) is a common malignancy. Treatment failure is mainly due to loco-regional disease recurrence. KAI1 is a newly discovered metastasis suppressor gene. Fifty-seven patients with primary OSCC underwent surgery alone or surgery and adjuvant radiotherapy. Immunohistochemical evaluation of KAI1/CD82 and p53 proteins was carried out on specimen obtained at surgery. Within neoplastic fields, KAI1/CD82 expression was downregulated and negative in 42/57 (73.7%) cases. p53 expression was positive in 26/57 (45.6%) cases. No correlation was noted between KAI1/CD82 and p53 expression or clinicopathological parameters. Univariate and multivariate Cox proportional hazard models showed a correlation between KAI1/CD82 expression with disease free survival (P = 0.01, P = 0.009) and overall survival (P = 0.04, P = 0.053) respectively.

Effects of KAI1 gene on growth and invasion of human hepatocellular carcinoma MHCC97-H cells

AIM: To study the effects of sense and antisense KAI1 genes on the growth and invasion of human hepatocellular carcinoma (HCC) cell line MHCC97-H.

METHODS: KAI1 sense and antisense eukaryotic expression plasmids were constructed using subclone technique and transfected into MHCC97-H cells respectively by DOTAP liposome. After successful transfection was confirmed, in vitro growth curve, cell cycles, plate clone formation efficiency, invasive ability in Boyden Chamber assay and ultrastructural morphology were studied.

RESULTS: KAI1 sense and antisense genes had no significant effects on the cell growth curve and cell cycles. After transfection with sense KAI1 gene, decreased invasive ability in Boyden Chamber assay and decreased amount of mitochondria, but no significant changes of plate clone formation efficiency were observed in MHCC97-H-S cells. The plate clone formation efficiency and invasive ability in Boyden Chamber assay were significantly increased in MHCC97-H-AS cells, after transfection with antisense KAI1 gene. Furthermore, increased amount of mitochondria, rough endoplasmic reticulum, Golgi apparatus and expanded endoplasmic reticulum were also noted in MHCC97-H-AS cells.

CONCLUSION: Changes of KAI1 expression in HCC cells may alter their invasive and metastasis ability of the tumor.

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Effects of KAI1/CD82 on biological behavior of human colorectal carcinoma cell line

AIM: To investigate the effects of KAI1/CD82 on biological behavior of colorectal carcinoma cells.

METHODS: KAI1 cDNA was transfected into highly malignant colorectal carcinoma cell line, LoVo, which had low level of endogenous KAI1 expression, and established stable transfectant clones with high KAI1/CD82 expression. The cell-cell adhesion, cell aggregation, cell-matrix adhesion and cell invasion assay were performed to determine whether KAI1 transfectant could have an effect on proliferation, adhesion and tumor metastasis in comparison with the control transfectant cells.

RESULTS: KAI1 expression did not alter in vitro cell proliferation. But the KAI1 transfectant cells exhibited significantly increased homotypic cell-cell adhesion and cell aggregation in comparison with the control transfectant cells(P < 0.05). Furthermore, KAI1 expression significantly suppressed the cell adhesion to extracellular matrix components and in vitro cell invasion in KAI1-transfected LoVo cells. The data indicated that KAI1 expression significantly suppressed the metastatic potential of KAI1-transfected LoVo cells.

CONCLUSION: Our results suggest that KAI1 might function as a negative regulator of colorectal carcinoma metastasis.