METCAM/MUC18 is a Biomarker and Therapeutic Target for Prostate Cancer.

Background: METCAM/MUC18 may be a new serum biomarker for predicting malignant propensity of prostate cancer by using a modified lateral flow immune assay (modified LFIA), which used the extremely high affinity between biotin and streptavidin and two antibody combinations to increase the sensitivity and specificity of traditional LFIA. To increase the sensitivity and specificity to the highest degree, in this report we further improved this modified LFIA by using a new antibody combination, which includes a biotinylated home-made chicken antibody and a nano-gold conjugated rabbit antibody (MBS416853).

Materials And Methods: A calibration curve was established from two recombinant METCAM/MUC18 proteins (C-terminus GST as the positive control and NM-GST the negative control) and used for determining METCAM/MUC18 concentrations in 36 serum specimens from normal individuals and patients of benign prostatic hypertrophy (BPH) patients, prostatic intraepithelial neoplasia (PIN), and prostate cancer at various Gleason scores and after treatment.

METCAM Is a Potential Biomarker for Predicting the Malignant Propensity of and as a Therapeutic Target for Prostate Cancer.

Prostate cancer is the second leading cause of cancer-related death worldwide. This is because it is still unknown why indolent prostate cancer becomes an aggressive one, though many risk factors for this type of cancer have been suggested. Currently, many diagnostic markers have been suggested for predicting malignant prostatic carcinoma cancer; however, only a few, such as PSA (prostate-specific antigen), Prostate Health Index (PHI), and PCA3, have been approved by the FDA.

METCAM/MUC18 Plays a Tumor Suppressor Role in the Development of Nasopharyngeal Carcinoma Type I.

From previous studies of negatively correlating the expression of human METCAM/MUC18 with the pathology of nasopharyngeal carcinoma (NPC), we have suggested that human METCAM/MUC18 (huMETCAM/MUC18) might play a tumor suppressor role in the development of nasopharyngeal carcinoma. To scrutinize this hypothesis, we investigated the effects of huMETCAM/MUC18's over-expression on in vitro cellular behavior and on the in vivo tumorigenesis of one NPC cell line (NPC-TW01). HuMETCAM/MUC18 cDNA was first transfected into the NPC-TW01 cell line, which was established from NPC type I, and many G418-resistant clones were obtained.

Enforced Expression of METCAM/MUC18 Decreases In Vitro Motility and Invasiveness and Tumorigenesis and In Vivo Tumorigenesis of Human Ovarian Cancer BG-1 Cells.

Objectives: We tested if METCAM/MUC18 overexpression also plays a suppressor role in another human ovarian cancer cell line, BG-1, in addition to the SK-OV3 cell line.

Methods: Human ovarian cancer BG-1 cells were transfected with METCAM/MUC18 cDNA and G418-resistant clones expressing different levels of METCAM/MUC18 were isolated. These clones were used to test the effects of enforced expression of METCAM/MUC18 on in vitro motility, invasiveness, and anchorage-independent colony formation (in vitro tumorigenesis), and in vivo tumorigenesis after SC injection and after IP injection in female athymic nude mice.

Validating METCAM/MUC18 as a Novel Biomarker to Predict the Malignant Potential of Prostate Cancer at an Early Stage by Using a Modified Gold Nanoparticles-Based Lateral Flow Immunoassay.

(1) Background: To further validate METCAM/MUC18 as a diagnostic biomarker for prostate cancer, a modified Lateral Flow Immune Assay (LFIA) with increased sensitivity and specificity was designed by taking advantage of the extremely high affinity between biotin and streptavidin and used. (2) Methods: The combination of a commercial biotinylated rabbit antibody (EPP11278), or the home-made biotinylated chicken antibody, and the nano-gold conjugated home-made chicken antibody or a commercial rabbit antibody (EPP11278), had the higher sensitivity and specificity in this modified LFIA to establish calibration curves from the two recombinant METCAM/MUC18 proteins and were used for determining METCAM/MUC18 concentrations in serum specimens from normal individuals, benign prostatic hyperplasia (BPH) patients, prostatic intraepithelial neoplasia (PIN) patients, prostate cancer patients with various Gleason scores, and treated patients. (3) Results: Data obtained by this modified LFIA were statistically better than traditional LFIA and prostate-specific antigen (PSA) test.

METCAM/MUC18 is a new early diagnostic biomarker for the malignant potential of prostate cancer: Validation with Western blot method, enzyme-linked immunosorbent assay and lateral flow immunoassay.

Background: METCAM/MUC18 expression was increased with the malignant progression of prostate cancer and also a bona fide metastatic gene, capable of initiating and driving the metastasis of a non-metastatic human prostate cancer cell line to multiple organs.

Objective: We explored if METCAM/MUC18 was detectable in human serum and a novel biomarker to predict malignant propensity of prostate cancer.

Materials And Methods: Two antibodies were identified by Western blot analysis having the highest sensitivity and specificity to establish calibration curves from the recombinant METCAM/MUC18 proteins.

METCAM/MUC18 Decreases the Malignant Propensity of Human Ovarian Carcinoma Cells.

METCAM/MUC18 is an integral membrane cell adhesion molecule (CAM) in the Ig-like gene super-family. It can carry out common functions of CAMs which is to perform intercellular interactions and interaction of cell with extracellular matrix in tumor microenvironment, to interact with various signaling pathways and to regulate general behaviors of cells. We and other two groups previously suggested that METCAM/MUC18 probably be utilized as a biomarker for predicting the malignant tendency of clinical ovarian carcinomas, since METAM/MUC18 expression appears to associate with the carcinoma at advanced stages.

Ectopic expression of MCAM/MUC18 increases in vitro motility and invasiveness, but decreases in vivo tumorigenesis and metastasis of a mouse melanoma K1735-9 subline in a syngeneic mouse model.

Ectopic expression of MCAM/MUC18, a cell adhesion molecule in the immunoglobulin-like gene superfamily, induces two moMCAM/MUC18-minus, non-metastatic mouse melanoma K1735 sublines, K3 (tumor/met) and K10 (tumor/met), to metastasize to lungs in a syngeneic C3H mouse model. In this report, we extended investigation of effects of moMCAM/MUC18 expression on tumorigenesis and metastasis in another lowly metastatic, however highly tumorigenic moMCAM/MUC18-minus mouse melanoma K1735 subline, K9 (tumor/met). We transfected this subline with the moMCAM/MUC18 cDNA, selected for G418-resistant clones with different expression levels of moMCAM/MUC18, and used them for testing effects of MCAM/MUC18 expression on in vitro growth rate, motility, and invasiveness, in vivo subcutaneous tumor growth, and pulmonary metastasis in syngeneic C3H brown mice.

METCAM/MUC18 promoted tumorigenesis of human breast cancer SK-BR-3 cells in a dosage-specific manner.

Objective: Overexpression of METCAM/MUC18, an immunoglobulin-like cell-adhesion molecule, promotes tumorigenesis and progression of human breast cancer cells. We also observed an intriguing phenomenon that a high-expressing SK-BR-3 clone manifested a transient tumor suppression effect in vivo. The purpose of this study was to understand if this was caused by clonal variation, METCAM/MUC18-dosage effect, or the number of cells injected.

METCAM/MUC18 is a novel tumor and metastasis suppressor for the human ovarian cancer SKOV3 cells.

Background: Increased expression of METCAM/MUC18, a trans-membrane cell adhesion molecule in the Ig-like gene superfamily, has been associated with the malignant progression of epithelial ovarian carcinomas. To investigate if this is a fortuitous correlation or if METCAM/MUC18 actually plays a role in the progression of the cancer, we tested effects of enforced expression of METCAM/MUC18 on in vitro behaviors, in vivo tumorigenesis, and in vivo malignant progression of human ovarian cancer SK-OV-3 cells, which minimally expressed this protein.

Methods: For in vitro and in vivo tests, we transfected human METCAM/MUC18 cDNA gene into SK-OV-3 cells in a mammalian expression vector pcDNA3.

Frequent and increased expression of human METCAM/MUC18 in cancer tissues and metastatic lesions is associated with the clinical progression of human ovarian carcinoma.

Objectives: Human METCAM/MUC18 (huMETCAM/MUC18), a cell adhesion molecule, plays an important role in the progression of several epithelial cancers; however, its role in the progression of epithelial ovarian cancers is unknown. To initiate the study we determined expression of this protein in normal and cancerous ovarian tissues, cystadenomas, metastatic lesions, and ovarian cancer cell lines.

Materials And Methods: Immunoblotting and immunohistochemical (IHC) methods were used to determine huMETCAM/MUC18 expression in lysates of frozen and formalin-fixed, paraffin-embedded tissue sections of normal human ovaries, and ovarian (benign) cystadenomas, carcinomas and metastatic lesions.

Significance of expression of human METCAM/MUC18 in nasopharyngeal carcinomas and metastatic lesions.

Human METCAM/MUC18, a cell adhesion molecule (CAM) in the immunoglobulin-like gene super family, plays a dual role in the progression of several epithelium cancers; however, its role in the nasopharyngeal carcinoma (NPC) remains unclear. To initiate the study we determined human METCAM/MUC18 expression in tissue samples of normal nasopharynx (NP), NPCs, and metastatic lesions, and in two established NPC cell lines. Immunoblotting analysis was used for the determination in lysates of frozen tissues, and immunohistochemistry (IHC) for expression in formalin-fixed, paraffin-embedded tissue sections of 7 normal nasopharynx specimens, 94 NPC tissue specimens, and 3 metastatic lesions.

Dual Roles of METCAM in the Progression of Different Cancers.

METCAM, an integral membrane cell adhesion molecule (CAM) in the Ig-like gene superfamily, is capable of performing typical functions of CAMs, such as mediating cell-cell and cell-extracellular interactions, crosstalk with intracellular signaling pathways, and modulating social behaviors of cells. METCAM is expressed in about nine normal cells/tissues. Aberrant expression of METCAM has been associated with the progression of several epithelial tumors.

METCAM/MUC18 augments migration, invasion, and tumorigenicity of human breast cancer SK-BR-3 cells.

Previous research has identified METCAM/MUC18, an integral membrane cell adhesion molecule (CAM) in the Ig-like gene super-family, as a promoter or a suppressor in the development of human breast cancer by MCF7, MDA-MB-231, and MDA-MB-468. To resolve these conflicting results we have investigated the role of this CAM in the progression of the three aforementioned cell lines plus one additional human breast cancer cell line, SK-BR-3. We transfected the SK-BR-3 cells with human METCAM/MUC18 cDNA to obtain G418-resistant clones, which expressed different levels of the protein and which were used to test the effect of human METCAM/MUC18 expression on in vitro motility, invasiveness, anchorage-independent colony formation in soft agar, disorganized growth in a 3D basement membrane culture assay, and in vivo tumorigenesis in athymic nude mice.

Up-regulation of METCAM/MUC18 promotes motility, invasion, and tumorigenesis of human breast cancer cells.

Background: Conflicting research has identified METCAM/MUC18, an integral membrane cell adhesion molecule (CAM) in the Ig-like gene super-family, as both a tumor promoter and a tumor suppressor in the development of breast cancer. To resolve this, we have re-investigated the role of this CAM in the progression of human breast cancer cells.

Methods: Three breast cancer cell lines were used for the tests: one luminal-like breast cancer cell line, MCF7, which did not express any METCAM/MUC18, and two basal-like breast cancer cell lines, MDA-MB-231 and MDA-MB-468, which expressed moderate levels of the protein.

Enforced expression of METCAM/MUC18 increases tumorigenesis of human prostate cancer LNCaP cells in nude mice.

Purpose: Metastasis cell adhesion molecule/MUC18, a cell adhesion molecule in the Ig-like gene super family, is a key determinant in prostate cancer cell progression. However, the mechanisms by which human metastasis cell adhesion molecule/MUC18 stimulates progression are poorly understood. To investigate this and determine whether human metastasis cell adhesion molecule/MUC18 may act as a possible tumor progression gene, we studied the effect of its enforced expression on LNCaP cell tumorigenesis.

Enforced expression of MCAM/MUC18 increases in vitro motility and invasiveness and in vivo metastasis of two mouse melanoma K1735 sublines in a syngeneic mouse model.

Human MCAM/MUC18 has been shown to increase metastasis of human melanoma cells in xenograft mouse systems. To be more relevant to understanding the progression of clinical melanoma and for designing better preclinical therapeutic trials, it is highly desirable to establish a syngeneic mouse model for studying the mechanisms of MCAM/MUC18-mediated tumorigenesis and metastasis of melanoma cells. To reach this goal, we transfected the mouse MCAM/MUC18 (moMCAM/MUC18) cDNA into two MCAM/MUC18-minus, low-metastatic mouse melanoma K1735 sublines, K1735-10 (tumor(-)/met(low)) and K1735-3 (tumor(+)/met(low)), and selected for G418-resistant clones, which expressed different levels of moMCAM/MUC18, and used for testing the effect of MCAM/MUC18 overexpression on their in vitro growth rate, motility, and invasiveness and in vivo subcutaneous tumor growth and pulmonary metastasis in syngeneic mice.

Non-invasive bioluminescent detection of prostate cancer growth and metastasis in a bigenic transgenic mouse model.

Background: We previously established a bioluminescent transgenic mouse model, sPSA-Luc, with luciferase gene expression restricted to the prostate under the control of the supra prostate-specific antigen (sPSA) promoter. We now assess the feasibility of generating bigenic mice, TRAMP-Luc, with the sPSA-Luc as the founder strain crossbred with TRAMP (transgenic adenocarcinoma mouse prostate) mice, to evaluate non-invasively the metastatic potential of prostate tumors.

Methods: TRAMP-Luc mice were obtained as [C57BL/6 TRAMP x FVB sPSA-Luc] F1 offspring.

Increased expression of MUC18 correlates with the metastatic progression of mouse prostate adenocarcinoma in the TRAMP model.

Purpose: The transgenic adenocarcinoma mouse prostate (TRAMP) model is a paradigm that closely mimics the progression of clinical prostate cancer. We have previously reported that MUC18, a cell adhesion molecule in the Ig gene superfamily, is a marker as well as an important mediator for the metastatic potential of human prostate cancer cells. In this study we investigated the possible correlation of increased MUC18 expression with the malignant progression of prostate cancer in the TRAMP model.

Ectopical expression of human MUC18 increases metastasis of human prostate cancer cells.

MUC18, a cell adhesion molecule (CAM), has been reported to be a diagnostic marker for the early detection of the metastatic potential of prostate cancers as well as implicated to be an important determinant for mediating the tumorigenesis and metastasis of prostate cancer. To test the hypothesis, we further investigated the possible role of MUC18 in the malignant progression of human prostate cancer. The human MUC18-minus, non-metastatic human prostate cancer LNCaP cells were transfected with the human cytomegalovirus immediate-early gene (HCMV-IE) promoter-driven human MUC18 (huMUC18) cDNA.