Roles of CEACAM1 in cell communication and signaling of lung cancer and other diseases

Oral squamous cell carcinomas: state of the field and emerging directions

Oral squamous cell carcinoma (OSCC) develops on the mucosal epithelium of the oral cavity. It accounts for approximately 90% of oral malignancies and impairs appearance, pronunciation, swallowing, and flavor perception. In 2020, 377,713 OSCC cases were reported globally. According to the Global Cancer Observatory (GCO), the incidence of OSCC will rise by approximately 40% by 2040, accompanied by a growth in mortality. Persistent exposure to various risk factors, including tobacco, alcohol, betel quid (BQ), and human papillomavirus (HPV), will lead to the development of oral potentially malignant disorders (OPMDs), which are oral mucosal lesions with an increased risk of developing into OSCC. Complex and multifactorial, the oncogenesis process involves genetic alteration, epigenetic modification, and a dysregulated tumor microenvironment. Although various therapeutic interventions, such as chemotherapy, radiation, immunotherapy, and nanomedicine, have been proposed to prevent or treat OSCC and OPMDs, understanding the mechanism of malignancies will facilitate the identification of therapeutic and prognostic factors, thereby improving the efficacy of treatment for OSCC patients. This review summarizes the mechanisms involved in OSCC. Moreover, the current therapeutic interventions and prognostic methods for OSCC and OPMDs are discussed to facilitate comprehension and provide several prospective outlooks for the fields.

Changes in the expression of cancer- and metastasis-related genes and proteins after metformin treatment under different metabolic conditions in endometrial cancer cells

Research question

Hyperinsulinemia and elevated estrogen levels are known risk factors for endometrial cancer (EC) development and are associated with obesity, type 2 diabetes mellitus (T2DM), insulin resistance, among others. Metformin, an insulin-sensitizing drug, displays anti-tumor effects in cancer patients, including EC, but the mechanism of action is still not completely understood. In the present study, the effects of metformin on gene and protein expression were investigated in pre- and postmenopausal EC in vitro models in order to identify candidates that are potentially involved in the drug's anti-cancer mechanism.

Design

After treating the cells with metformin (0.1 and 1.0 mmol/L), changes in the expression of >160 cancer- and metastasis-related gene transcripts were evaluated with RNA arrays. A total of 19 genes and 7 proteins were selected for a follow-up expression analysis, including further treatment conditions, in order to evaluate the influence of hyperinsulinemia and hyperglycemia on metformin-induced effects.

Results

Changes in the expression of BCL2L11, CDH1, CDKN1A, COL1A1, PTEN, MMP9 and TIMP2 were analyzed on gene and protein level. The consequences resulting from the detected expression changes as well as the influence of varying environmental influences are discussed in detail. With the presented data, we contribute to a better understanding of the direct anti-cancer activity of metformin as well as its underlying mechanism of action in EC cells.

Conclusions

Although further research will be necessary to confirm the data, the influence of different environmental settings on metformin-induced effects could be highlighted with the presented data. Additionally, gene and protein regulation were not similar in the pre- and postmenopausal in vitro models.

Krüppel-like factor 4 regulates the cytolytic effector function of exhausted CD8 T cells

Exhausted CD8 T cells during chronic inflammatory responses against viral infections and cancer are phenotypically and functionally heterogeneous. In particular, CD8 T cells with cytolytic effector function have been recently identified among the exhausted CD8 T cell subsets. However, the regulation of their differentiation and function remains largely unknown. Here, we report that Krüppel-like factor 4 (KLF4) is a critical regulator of the exhaustion process, promoting the cytolytic effector function of exhausted CD8 T cells. KLF4-expressing CD8 T cells in exhaustion contexts showed the features of transitory effector CD8 T cells. Enforced KLF4 expression increased CD8 T cell differentiation into transitory effector subsets and enhanced their antitumor immunity. We further demonstrated that KLF4 also showed a capacity of reinvigorating exhausted CD8 T cells. Last, high KLF4 expression was positively correlated with a favorable prognosis in human patients with cancer. Our study highlights the potential impacts of KLF4 on CD8 T cell exhaustion and antitumor immune therapy.

NLR family CARD domain containing 5 promotes hypoxia-induced cancer progress and carboplatin resistance by activating PI3K/AKT via carcinoembryonic antigen related cell adhesion molecule 1 in non-small cell lung cancer

It is well known that non-small cell lung cancer (NSCLC) is a malignant tumor with high incidence in the world. We aimed to clarify a possible target and identify its precise molecular biological mechanism in NSCLC. NLR family CARD domain containing 5 (NLRC5) is widely expressed in tissues and exerts a vital role in anti-tumor immunity. We determined NLRC5 expression by RT-qPCR and western blot assay. The role of NLRC5 in the development of NSCLC was assessed by a loss-of-function assay. CCK-8, Annexin-V-FITC/PI Apoptosis Detection Kit, Transwell, and wound healing assays were used to determine the cell functions. Drug resistance-related proteins were analyzed by western blot assay. Furthermore, the modulation of NLRC5 on carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1) expression and subsequent PI3K/AKT signaling was assessed. In this study, a hyper-expression of NLRC5 was found in NSCLC tissues and cell lines. Knockdown of NLRC5 suppressed cell viability, invasion, and migration, and furthermore promoted cell apoptosis in NSCLC cells. Moreover, under normoxia or hypoxia treatment, the upregulation of NLRC5 was related to carboplatin resistance. NLRC5 silencing increased carboplatin-resistant cell chemosensitivity, as evidenced by the increase in the cell inhibition rate and decrease in drug resistance-related protein expression. Mechanistically, NLRC5 knockdown inhibited the expression of CEACAM1 and subsequently blocked the PI3K/AKT signaling pathway. In conclusion, NLRC5 promotes the malignant biological behaviors of NSCLC cells by activating the PI3K/AKT signaling pathway via the regulation of CEACAM1 expression under normoxia and hypoxia.

Unraveling the Expression Patterns of Immune Checkpoints Identifies New Subtypes and Emerging Therapeutic Indicators in Lung Adenocarcinoma

Immune checkpoint genes (ICGs) play pivotal roles in tumor immune microenvironment (TIME), and thus, targeting them represents a promising strategy for cancer immunotherapy. However, the genetic landscape of ICGs in lung adenocarcinoma (LUAD) is still unknown. Herein, we comprehensively evaluated the ICG expression profiles of 1439 LUAD samples and linked ICG expression patterns with infiltration of immune cells, clinical features, and response to immune checkpoint blockade (ICB). The ICGscore was developed to quantify ICG expression patterns of individual patient by principal component analysis algorithms. Three distinct ICG expression patterns and three ICG-related genomic clusters were determined, which were implicated in different clinical outcomes, level of immune infiltrates, and biological process. LUAD patients were subdivided into high- and low-ICGscore subgroups. Patients with higher ICGscore were characterized by favorable survival outcomes, increased immune cell infiltration, and enhanced expression of ICGs. Further analysis revealed that lower ICGscore was associated with greater tumor mutation loads and higher mutation rates of TTN, KEAP1, and ZFHX4. High ICGscore has the potential to be a robust indicator in clinical benefit of immunotherapy. Taken together, unraveling the ICG expression patterns will advance our understanding of heterogeneity of TIME and guides more effective immunotherapeutic strategies in LUAD.

Perinatal Exposure to Nicotine Alters Sperm RNA Profiles in Rats

Perinatal exposure to smoking has been associated with childhood asthma, one of the most common pediatric conditions affecting millions of children globally. Of great interest, this disease phenotype appears heritable as it can persist across multiple generations even in the absence of persistent exposure to smoking in subsequent generations. Although the molecular mechanisms underlying childhood asthma induced by perinatal exposure to smoking or nicotine remain elusive, an epigenetic mechanism has been proposed, which is supported by the data from our earlier analyses on germline DNA methylation (5mC) and histone marks (H3 and H4 acetylation). To further investigate the potential epigenetic inheritance of childhood asthma induced by perinatal nicotine exposure, we profiled both large and small RNAs in the sperm of F1 male rats. Our data revealed that perinatal exposure to nicotine leads to alterations in the profiles of sperm-borne RNAs, including mRNAs and small RNAs, and that rosiglitazone, a PPARγ agonist, can attenuate the effect of nicotine and reverse the sperm-borne RNA profiles of F1 male rats to close to placebo control levels.

High expression of carcinoembryonic antigen-associated cell adhesion molecule 1 is associated with microangiogenesis in esophageal squamous cell carcinoma

Background

Carcinoembryonic antigen-associated cell adhesion molecule 1 (CEACAM1) plays an important role in tumor progression, invasion, and metastasis by regulating angiogenesis. However, the expression of CEACAM1 in esophageal cancer tissues and its relationship with microvessel density (MVD) has not been investigated before.

Methods

MVD and the expression of CEACAM1 in 80 esophageal squamous cell carcinoma (ESCC) tissues were determined by immunohistochemistry (IHC). Statistical analyses were conducted to test the associations between CEACAM1 expression, MVD level, clinicopathologic factors, and prognosis.

Results

The expression level of CEACAM1 was significantly correlated with the level of MVD. Kaplan-Meier analysis showed no significant correlations between local recurrence and distant metastasis in high MVD and high CEACAM-1 expression group. Kaplan-Meier analysis also showed a poorer survival rate in patients with high MVD or high CEACAM-1. Univariate analysis showed that MVD levels, CEACAM1 expression, lymph node metastasis, and patient's age were prognostic factors for postoperative ESCC. The results of multivariate analysis indicated that the significance of the prognostic effect of CEACAM-1 expression observed by univariate analysis disappeared when analyzed together with MVD, suggesting that the prognostic impact of CEACAM1 expression was dependent on MVD level, while MVD was still a significant prognostic factor for adverse cancer-related survival (P=0.001).

Conclusions

The CEACAM1 expression is a potential prognostic factor for postoperative ESCC combined with MVD level.

Cell-dependent regulation of vasculogenic mimicry by carcinoembryonic antigen cell adhesion molecule 1 (CEACAM1)

Vasculogenic mimicry (VM) promotes tumor migration, metastasis, and invasion in various types of cancer, but the relationship between VM and these phenotypes remains undefined. In this study, we examined carcinoembryonic antigen cell adhesion molecule 1 (CEACAM1) as a novel target of VM. We found that ectopic expression of CEACAM1 in HT1080 human fibrosarcoma cells suppressed the formation of a VM-like network. Further, cell migration and proliferation were abated by the introduction of CEACAM1 into HT1080 cells. Conversely, knockout (KO) of the CEACAM1 gene in SK-MEL-28 melanoma cells, which normally express high levels of CEACAM1, inhibited formation of a VM-like network, which was covered on reintroduction of CEACAM1. These results suggest that CEACAM1 differentially regulates formation of the VM-like network between cancer cell types and implicate CEACAM1 as a novel therapeutic target in malignant cancer.

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CEACAM1 is not expressed in HT1080 cells, and overexpression of CEACAM1 in HT1080 cells suppresses vasculogenic mimicry.

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CEACAM1 is highly expressed in SK-MEL-28 cells, and deletion of CEACAM1 in SK-MEL-28 cells abolishes vasculogenic mimicry.

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CEACAM1 regulates vasculogenic mimicry in a cell-dependent manner.

The Monoclonal Antibody NEO-201 Enhances Natural Killer Cell Cytotoxicity Against Tumor Cells Through Blockade of the Inhibitory CEACAM5/CEACAM1 Immune Checkpoint Pathway

Background: Natural killer (NK) cells are essential to innate immunity and participate in cancer immune surveillance. Heterophilic interactions between carcinoembryonic antigen (CEA) on tumor cells and carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1) on NK cells inhibit NK cell cytotoxicity against tumor cells. NEO-201 is a humanized IgG1 monoclonal antibody that recognizes members of CEACAM family, expressed specifically on a variety of human carcinoma cell lines and tumor tissues. This investigation was designed to determine whether the binding of NEO-201 with CEACAM5 on tumor cells can block the CEACAM5/CEACAM1 interaction to restore antitumor cytotoxicity of NK cells. Materials and Methods: In vitro functional assays, using various human tumor cell lines as target cells and NK-92 cells as effectors, were conducted to assess the ability of NEO-201 to block the interaction between CEACAM5 on tumor cells and CEACAM1 on NK cells to enhance the in vitro killing of tumor cells by NK-92. NK-92 cells were used as a model of direct NK killing of tumor cells because they lack antibody-dependent cellular cytotoxicity activity. Results: Expression profiling revealed that various human carcinoma cell lines expressed different levels of CEACAM5⁺ and NEO-201⁺ cells. Addition of NEO-201 significantly enhanced NK-92 cell cytotoxicity against highly CEACAM5⁺/NEO-201⁺ expressing tumor cells, suggesting that its activity is correlated with the level of CEACAM5⁺/NEO-201⁺ expression. Conclusions: These findings demonstrate that NEO-201 can block the interaction between CEACAM5 on tumor cells and CEACAM1 on NK cells to reverse CEACAM1-dependent inhibition of NK cytotoxicity.

Effect of Long-Term Mesalamine Therapy on Cancer-Associated Gene Expression in Colonic Mucosa of Patients with Ulcerative Colitis

BACKGROUND

The role of 5-aminosalicylic acid (5-ASA or mesalamine) in the prevention of colorectal cancer in ulcerative colitis (UC) patients was reported, but the effect on molecular targets in UC colon mucosa is unknown.

AIM

This observational study evaluates gene expression levels of 5-ASA targets using serial colon biopsy specimens from UC patients undergoing long-term 5-ASA therapy.

METHODS

Transcript levels were compared between colonoscopic biopsy specimens collected from 62 patients at initial and final follow-up colonoscopy at 2-6 years. All patients had mild-to-moderate UC and were undergoing long-term 5-ASA maintenance. Stepwise multiple linear regression analyses were performed to correlate changes in transcript levels with therapeutic response (Mayo clinical score endoscopy and DAI and/or Nancy histopathology score) and nonclinical variables.

RESULTS

The transcript levels of colorectal carcinogenesis-associated known 5-ASA target genes were significantly reduced after prolonged 5-ASA therapy (P < 0.005-0.03). Multiple linear regression models predicted significant association between transcript levels of Ki-67, NF-kB (p65), PPARγ, COX-2 and IL-8, CDC25A, and CXCL10 with duration of drug (5-ASA) exposure (P ≤ 0.05). Ki-67, NF-kB (p65), and CXCL10 transcripts were also correlated with reduced endoscopy sub-score (P ≤ 0.05). COX-2, IL-8, CDC25A, and TNF transcripts strongly correlated with DAI sub-scores (P ≤ 0.05). Only COX-2 and IL-8 transcript levels correlated (P ≤ 0.05) with Nancy histological score.

CONCLUSION

This study provides molecular evidence of changes in carcinogenesis-related targets/pathways in colon tissue during long-term 5-ASA maintenance therapy that may contribute to the observed chemopreventive effects of 5-ASA in UC patients.

Expression of Chosen Carcinoembryonic-Related Cell Adhesion Molecules in Pancreatic Intraepithelial Neoplasia (PanIN) Associated with Chronic Pancreatitis and Pancreatic Ductal Adenocarcinoma (PDAC)

Aims: Carcinoembryonic antigen-related cell adhesion molecules (CEACAMs) are members of the glycosylphosphatidylinositol (GPI)-linked immunoglobulin (Ig) superfamily and take part in regulation of cell adhesion, tumor suppression and angiogenesis. Overexpression of CEACAM 1, 5 and 6 is widely described in several gastrointestinal epithelial tumors. The aim of study was to evaluate the expression of CEACAM 1, CEACAM 5 and CEACAM 6 in the most common precursor lesions of pancreatic ductal adenocarcinoma -pancreatic intraepithelial neoplasia (PanIN). Methods and results: The study group consisted of 32 patients treated for chronic pancreatitis and 38 patients with pancreatic ductal adenocarcinoma who also had pancreatic intraepithelial neoplasia. The expression of CEACAM was performed by immunohistochemical method and evaluated using 3-point scale: 0 - lack of positive reaction in pancreatic intraepithelial neoplasia, 1 (weak and moderate) - reaction present in 1-30% epithelial cells in PanIN and 2 (strong) - reaction present in >30% epithelial cells in PanIN. Expression of CEACAM 1, 5 and 6 increased with increasing degree of advancement of PanIN. Differences in expression of CEACAM 1, 5 and 6 between normal pancreatic ducts and different degrees of PanIN were statistically significant (p<0.001). We observed relationship between CEACAM1 expression and localization of PanIN in different parts of the pancreas. Conclusions: CEACAM 1, CEACAM 5 and CEACAM 6 expression appears to be an early event in pancreatic carcinogenesis. Moreover, expression of CEACAM 1, 5 and 6 may represent a useful biomarker that may aid in the identification of precancerous lesions in the pancreas.

Prognostic implication of CEACAM1 expression in squamous cell carcinoma of the larynx: Pilot study

BACKGROUND

CEACAM1, a valuable biomarker for several cancers, have remained unexplored up to the present in laryngeal squamous cell carcinoma (LSCC). We aimed to examine CEACAM1 expression and evaluate its combinational clinical significance for the diagnosis or prognosis and treatment decision making in LSCC.

METHODS

CEACAM1 expression was assessed by immunohistochemistry in 54 LSCCs and evaluate its correlation with clinical and histopathological features.

RESULTS

CEACAM subtype 1 (CEACAM1) expression was positive in 50% of the cases. No significant difference was observed in relation to age, gender, tumor size, and tumor stage. CEACAM1 expression correlated with tumor grade, development of local recurrence, node and distant metastasis. Kaplan-Meier survival curves showed that CEACAM1 staining was inversely correlated with both overall and disease-specific 5-year survival.

CONCLUSIONS

Our study is the first to demonstrate that CEACAM1 expression is associated with an adverse prognosis in LSCC. CEACAM1 is a valuable biomarker and a promising therapeutic target in LSCC.

Knockdown of POLDIP2 suppresses tumor growth and invasion capacity and is linked to unfavorable transformation ability and metastatic feature in non-small cell lung cancer

The main problem in the treatment of non-small cell lung cancer (NSCLC) is metastasis. Epithelial-mesenchymal transition (EMT) is known as the critical signaling in tumor progression, metastasis, and also the drug resistance. In this study, we reported a novel gene Polymerase delta-interacting protein 2 (POLDIP2) was downregulated in NSCLC tissues and first demonstrated that overexpression of POLDIP2 increased the anchorage-independent growth (AIG) and invasiveness of H1299 cells. In addition, we examined that knockdown of POLDIP2 in H1299 and A549 cells reduced tumorigenicity and metastatic capacity in vitro and also in vivo. Moreover, downregulation of the cell proliferation marker cyclin D1 and EMT markers CDH2, Slug, and Twist was showed in H1299 cells by POLDIP2 knockdown, suggesting that the inhibition of malignancy was affected by modulating key genes for tumor growth and invasiveness. Taken together, our study is the first study that demonstrated that POLDIP2 gene was function as an oncogene in NSCLC and implied the oncogenic ability might be through promoting cell proliferation or EMT.

Immune checkpoint inhibitors for metastatic bladder cancer

Chemotherapy has represented the standard therapy for unresectable or metastatic urothelial carcinoma for more than 20 years. The growing knowledge of the interaction between tumour and immune system has led to the advent of new classes of drugs, the immune-checkpoints inhibitors, which are intended to change the current scenario. To date, immunotherapy is able to improve the overall responses and survival. Moreover, thanks to its safety profile immune-checkpoint inhibitors could be proposed also to patients unfit for standard chemotherapy. No doubts that these agents have started a revolution expected for years, but despite this encouraging results it appears clear that not all subjects respond to these agents and requiring the development of reliable predictive response factors able to isolate patients who can more benefit from these treatments as well as new strategies aimed to improve immunotherapy clinical outcome. In this review we describe the active or ongoing clinical trials involving Programmed Death Ligand 1 (PD-L1), Programmed Death receptor 1 (PD-1) and Cytotoxic-T Lymphocyte Antigen 4 (CTLA 4) inhibitors in urothelial carcinoma focusing our attention on the developing new immune-agents and combination strategies with immune-checkpoint inhibitors.

Up-regulation of carcinoembryonic antigen-related cell adhesion molecule 1 in gastrointestinal cancer and its clinical relevance

Serum carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1) is dysregulated in various malignant tumors and has been associated with tumor progression. However, the expression and regulatory mechanisms of serum CEACAM1 in gastrointestinal cancer are still unclear. The expression ratio of the CEACAM1-L and CEACAM1-S isoforms has seldom been investigated in gastrointestinal cancer. In this study, we intended to explore the expression and diagnostic value of CEACAM1 in gastrointestinal cancer. Serum CEACAM1 levels were measured by enzyme-linked immunosorbent assay. The protein expression and distribution of CEACAM1 in tumors were examined by immunohistochemical staining. The expression patterns and ratio of CEACAM1-L/S were analyzed by reverse transcription-polymerase chain reaction. The results showed that serum CEACAM1 levels were significantly higher in cancer patients than in healthy controls. CEACAM1 was found in secreted forms within the neoplastic glands, and its expression was more intense at the tumor invasion front. The CEACAM1-L/S (L:S) ratios were up-regulated during tumorigenesis. Our data suggest that the serum level of CEACAM1 may be used to discriminate gastrointestinal cancer patients from health controls.

A global view of regulatory networks in lung cancer: An approach to understand homogeneity and heterogeneity

A number of new biotechnologies are used to identify potential biomarkers for the early detection of lung cancer, enabling a personalized therapy to be developed in response. The combinatorial cross-regulation of hundreds of biological function-specific transcription factors (TFs) is defined as the understanding of regulatory networks of molecules within the cell. Here we integrated global databases with 537 patients with lung adenocarcinoma (ADC), 140 with lung squamous carcinoma (SCC), 9 with lung large-cell carcinoma (LCC), 56 with small-cell lung cancer (SCLC), and 590 without cancer with the understanding of TF functions. The present review aims at the homogeneity or heterogeneity of gene expression profiles among subtypes of lung cancer. About 5, 136, 52, or 16 up-regulated or 19, 24, 122, or 97down-regulated type-special TF genes were identified in ADC, SCC, LCC or SCLC, respectively. DNA-binding and transcription regulator activity associated genes play a dominant role in the differentiation of subtypes in lung cancer. Subtype-specific TF gene regulatory networks with elements should be an alternative for diagnostic and therapeutic targets for early identification of lung cancer and can provide insightful clues to etiology and pathogenesis.

Systems heterogeneity: An integrative way to understand cancer heterogeneity

The concept of systems heterogeneity was firstly coined and explained in the Special Issue, as a new alternative to understand the importance and complexity of heterogeneity in cancer. Systems heterogeneity can offer a full image of heterogeneity at multi-dimensional functions and multi-omics by integrating gene or protein expression, epigenetics, sequencing, phosphorylation, transcription, pathway, or interaction. The Special Issue starts with the roles of epigenetics in the initiation and development of cancer heterogeneity through the interaction between permanent genetic mutations and dynamic epigenetic alterations. Cell heterogeneity was defined as the difference in biological function and phenotypes between cells in the same organ/tissue or in different organs, as well as various challenges, as exampled in telocytes. The single cell heterogeneity has the value of identifying diagnostic biomarkers and therapeutic targets and clinical potential of single cell systems heterogeneity in clinical oncology. A number of signaling pathways and factors contribute to the development of systems heterogeneity. Proteomic heterogeneity can change the strategy and thinking of drug discovery and development by understanding the interactions between proteins or proteins with drugs in order to optimize drug efficacy and safety. The association of cancer heterogeneity with cancer cell evolution and metastasis was also overviewed as a new alternative for diagnostic biomarkers and therapeutic targets in clinical application.

CEACAM1 is overexpressed in oral tumors and related to tumorigenesis

Carcinoembryonic antigen-related adhesion molecule 1 (CEACAM1) is a type 1 transmembrane glycoprotein belonging to the CEA family, which has been known to exist as either soluble forms in body fluids or membrane-bound forms on the cell surface. Aberrant CEACAM1 expression is associated with tumorigenesis and has been reported in a variety of human tumors, especially malignancies. The aim of this study is to determine the expression of CEACAM1 in oral tumors, trying to study CEACAM1 different expressions as a function of histotype. CEACAM1 expression was observed by immunohistochemistry (IHC) with mouse anti-human antibody for CEACAM1. IHC was performed using avidin-biotin-diaminobenzidine staining. The results were expressed as average score ± SD (0 = negative/8 = highest) for each histotype. Oral tumors expressed more CEACAM1 than normal tissues including squamous and salivary epithelia (P < 0.05). In malignancies, the squamous cell carcinoma overexpressed CEACAM1, compared to well-differentiated squamous cell with more membranous expression; the intermediately and poorly differentiated squamous cell carcinoma showed more cytoplasmic expression (P < 0.05). In addition, the salivary tumors significantly expressed more CEACAM1 than squamous cell carcinoma (P < 0.05). So, we thought oral tumors overexpressed CEACAM1 and the cytoplasmic CEACAM1 might be involved in tumorigenesis, and also CEACAM1 might be regarded as a marker of salivary glandular tumors.