Trophoblast Cell Surface Antigen 2 Expression Research Articles

Trophoblast Cell Surface Antigen 2 (TROP2) as a Predictive Bio-Marker for the Therapeutic Efficacy of Sacituzumab Govitecan in Adenocarcinoma of the Esophagus.

Simple SummaryThe trophoblast cell surface antigen 2 (TROP2) is a protein produced by many carcinomas. Sacituzumab govitecan (SG) is a drug consisting of an antibody that binds to TROP2 on the tumor cell when TROP2 is present and is taken up into the cell interior after binding. The antibody is coupled with a cytotoxic substance (SN38) that is released inside the cell after uptake. As a result, a lethal dose of SN38 acts specifically in the tumor cell while having a small systemic effect, reducing the extent of side effects. We can show here that TROP2 is formed in nearly 90% of esophageal adenocarcinomas (EAC) and that sacituzumab govitecan is also effective in EAC. We can show that efficacy is dependent on the presence of TROP2 on the cancer cell - complete absence of TROP2 is associated with poor response rate to SG. We therefore advocate determining TROP2 at the protein level prior to therapy. Suitable immunohistochemical antibodies for routine testing exist.Introduction: The Trophoblast cell surface antigen 2 (TROP2) is expressed in many carcinomas and may represent a target for treatment. Sacituzumab govitecan (SG) is a TROP2–directed antibody-drug conjugate (ADC). Nearly nothing is known about the biological effectiveness of SG in esophageal adenocarcinoma (EAC). Material and Methods: We determined the TROP2 expression in nearly 600 human EAC. In addition, we used the EAC cell lines (ESO-26, OACM5.1C, and FLO-1) and a xenograft mouse model to investigate this relationship. Results: Of 598 human EACs analyzed, 88% showed varying degrees of TROP2 positivity. High TROP2 positive ESO-26 and low TROP2 positive OACM5.1C showed high sensitivity to SG in contrast to negative FLO-1. In vivo, the ESO-26 tumor shows a significantly better response to SG than the TROP2-negative FLO-1 tumor. ESO-26 vital tumor cells show similar TROP2 expression on all carcinoma cells as before therapy initiation, FLO-1 is persistently negative. Discussion: Our data suggest that sacituzumab govitecan is a new therapy option in esophageal adenocarcinoma and the TROP2 expression in irinotecan-naïve EAC correlates with the extent of treatment response by sacituzumab govitecan. TROP2 is emerging as a predictive biomarker in completely TROP2-negative tumors. This should be considered in future clinical trials.

Trophoblast cell-surface antigen 2 (TROP2) expression in triple-negative breast cancer

BackgroundTrophoblast cell-surface antigen 2 (TROP2) is related to tumor proliferation enhancement and poor prognosis. An antibody targeting TROP2 was developed to treat metastatic triple-negative breast cancer (TNBC) which has a limited treatment modality. To characterize the TROP2 expressing tumors in TNBC, we analyzed TROP2 expression in three cohorts; (1) primary tumor without neoadjuvant chemotherapy, (2) primary tumor with neoadjuvant chemotherapy, and (3) metastatic tumor.MethodsA total of 807 TNBC cases were evaluated for TROP2 immunohistochemical expression. We evaluated the TROP2 H-score distribution in the three cohorts. Tumors were divided into two groups based on TROP2 expression (high vs. low). We analyzed the relationship between clinicopathologic features and markers, including epidermal growth factor receptor, cytokeratin 5/6, p53, and Ki-67, and prognostic significance at high vs. low TROP2 expression.ResultsThere was no difference in TROP2 H-score distribution between the three cohorts. Moderate-to-strong membranous expression of TROP2 in at least 10% of tumor cells was present in 662 cases (82.0%) in Cohort 1, 59 cases (89.4%) in Cohort 2, and 23 cases (88.5%) in Cohort 3. There was no significant difference in clinicopathologic features between high vs. low TROP2 in all cohorts. TROP2 H-score was an independent poor prognostic factor for overall survival in Cohort 3.ConclusionsTNBC showed similar TROP2 expression regardless of neoadjuvant treatment or primary tumor/metastasis. Although the prognostic significance of TROP2 expression in metastatic TNBC has been revealed, further evaluation of the predictive value of TROP2 expression for targeted therapy is needed.

TROP2 Represents a Negative Prognostic Factor in Colorectal Adenocarcinoma and Its Expression Is Associated with Features of Epithelial-Mesenchymal Transition and Invasiveness.

Simple SummaryColorectal cancer (CRC) is one of the most common cancers worldwide. While the systemic treatment of CRC is based on chemotherapy, subsequent therapeutic options are far less effective. Trophoblast cell surface antigen 2 (TROP2) is highly expressed in many carcinomas, including CRC, where its expression correlates with a poor prognosis. Anti-TROP2-targeted therapy was approved for the treatment of breast and urothelial carcinomas. We aimed to determine whether TROP2 is a suitable target for the treatment of CRC. We demonstrated that TROP2 expression in CRC correlates with lymph node metastasis and poor tumor differentiation. An analysis of mouse tumor models, patient-derived organoids, and tumor cells revealed that TROP2 expression is associated with features related to epithelial–mesenchymal transition and invasiveness. Our results suggest that TROP2 targeting may be a promising approach, especially in the early phase of treatment.Trophoblastic cell surface antigen 2 (TROP2) is a membrane glycoprotein overexpressed in many solid tumors with a poor prognosis, including intestinal neoplasms. In our study, we show that TROP2 is expressed in preneoplastic lesions, and its expression is maintained in most colorectal cancers (CRC). High TROP2 positivity correlated with lymph node metastases and poor tumor differentiation and was a negative prognostic factor. To investigate the role of TROP2 in intestinal tumors, we analyzed two mouse models with conditional disruption of the adenomatous polyposis coli (Apc) tumor-suppressor gene, human adenocarcinoma samples, patient-derived organoids, and TROP2-deficient tumor cells. We found that Trop2 is produced early after Apc inactivation and its expression is associated with the transcription of genes involved in epithelial–mesenchymal transition, the regulation of migration, invasiveness, and extracellular matrix remodeling. A functionally similar group of genes was also enriched in TROP2-positive cells from human CRC samples. To decipher the driving mechanism of TROP2 expression, we analyzed its promoter. In human cells, this promoter was activated by β-catenin and additionally by the Yes1-associated transcriptional regulator (YAP). The regulation of TROP2 expression by active YAP was verified by YAP knockdown in CRC cells. Our results suggest a possible link between aberrantly activated Wnt/β-catenin signaling, YAP, and TROP2 expression.

ATF2 loss promotes tumor invasion in colorectal cancer cells via upregulation of cancer driver TROP2

In cancer, the activating transcription factor 2 (ATF2) has pleiotropic functions in cellular responses to growth stimuli, damage, or inflammation. Due to only limited studies, the significance of ATF2 in colorectal cancer (CRC) is not well understood. We report that low ATF2 levels correlated with worse prognosis and tumor aggressiveness in CRC patients. NanoString gene expression and ChIP analysis confirmed trophoblast cell surface antigen 2 (TROP2) as a novel inhibitory ATF2 target gene. This inverse correlation was further observed in primary human tumor tissues. Immunostainings revealed that high intratumoral heterogeneity for ATF2 and TROP2 expression was sustained also in liver metastasis. Mechanistically, our in vitro data of CRISPR/Cas9-generated ATF2 knockout (KO) clones revealed that high TROP2 levels were critical for cell de-adhesion and increased cell migration without triggering EMT. TROP2 was enriched in filopodia and displaced Paxillin from adherens junctions. In vivo imaging, micro-computer tomography, and immunostainings verified that an ATF2KO/TROP2high status triggered tumor invasiveness in in vivo mouse and chicken xenograft models. In silico analysis provided direct support that ATF2low/TROP2high expression status defined high-risk CRC patients. Finally, our data demonstrate that ATF2 acts as a tumor suppressor by inhibiting the cancer driver TROP2. Therapeutic TROP2 targeting might prevent particularly the first steps in metastasis, i.e., the de-adhesion and invasion of colon cancer cells.

EPCAM and TROP2 share a role in claudin stabilization and development of intestinal and extraintestinal epithelia in mice.

ABSTRACTEpithelial cell adhesion molecule (EPCAM) is a transmembrane glycoprotein expressed on the surface of most epithelial and epithelium-derived tumor cells and reported to regulate stability of epithelial tight junction proteins, claudins. Despite its widespread expression, loss of EPCAM function has so far only been reported to prominently affect intestinal development, resulting in severe early onset enteropathy associated with impaired growth and decreased survival in both humans and mice. In this study, we show that the critical role of EPCAM is not limited to intestinal tissues and that it shares its essential function with its only known homolog, Trophoblast cell surface antigen 2 (TROP2). EPCAM-deficient mice show significant growth retardation and die within 4 weeks after birth. In addition to changes in small and large intestines, loss of EPCAM results in hyperkeratosis in the skin and forestomach, hair follicle atrophy leading to alopecia, nephron hypoplasia in the kidney, proteinuria, and altered production of digestive enzymes by the pancreas. Expression of TROP2 partially, but not completely, overlaps with EPCAM in a number developing epithelia. Although loss of TROP2 had no gross impact on mouse development and survival, TROP2 deficiency generally compounded developmental defects observed in EPCAM-deficient mice, led to an approximately 60% decrease in embryonic viability, and further shortened postnatal lifespan of born pups. Importantly, TROP2 was able to compensate for the loss of EPCAM in stabilizing claudin-7 expression and cell membrane localization in tissues that co-express both proteins. These findings identify overlapping functions of EPCAM and TROP2 as regulators of epithelial development in both intestinal and extraintestinal tissues.

Abstract 1861: Trophoblast cell surface antigen 2 (TROP2) expression in human tumors: A tissue microarray study on 18,563 tumors

Abstract Trophoblast cell surface antigen 2 (TROP2) is the target of sacituzumab govitecan (SG), an antibody-drug conjugate that was recently approved for previously treated triple negative breast cancer and urothelial carcinomas. To comprehensively determine TROP2 expression in normal and neoplastic tissues, a tissue microarray containing 18,563 samples from 150 different tumor types and subtypes as well as 608 samples of 76 different normal tissue types was analyzed by immunohistochemistry. TROP2 positivity was found in most normal epithelial cell types and in 109 of 150 tumor categories, including 92 of 95 epithelial tumor categories. Particularly high rates of TROP2 positivity and highest expression levels were seen in squamous cell carcinomas of various origins and various categories of urothelial, breast, prostate, pancreatic, and ovarian cancers (>95% positive). High TROP2 expression was linked to advanced stage (p=0.0069) and nodal metastasis (p<0.0001) in colorectal cancer as well as to nodal metastasis in gastric adenocarcinoma (p=0.0246) and papillary thyroid cancer (p=0.0013). Low TROP2 expression was linked to advanced stage in urothelial carcinoma (p<0.0001), high pT (p=0.0024) and high grade (p<0.0001) in breast cancer, as well as with high grade (p=0.0005) and pT stage (p=0.0009) in papillary renal cell carcinomas. Associations between TROP2 expression and clinicopathological features were not found in clear cell renal cell carcinomas, high grade serous ovarian carcinomas, pancreatic adenocarcinomas and in endometroid endometrium carcinomas. In summary, TROP2 is abundantly expressed in a broad range of epithelial neoplasms. Both TROP2 upregulation and downregulation can be associated with cancer progression in a tumor type dependent manner. As anti-TROP2 cancer drugs have demonstrated efficiency and induce tolerable side effects they may be applicable to a broad range of tumor entities in the future. Citation Format: David Dum, Claudia Hube-Magg, Ronald Simon, Elena Bady, Tim Mandelkow, Niclas C. Blessin, Maximilian Lennartz, Guido Sauter, Sarah Minner, Andreas M. Luebke. Trophoblast cell surface antigen 2 (TROP2) expression in human tumors: A tissue microarray study on 18,563 tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1861.

TROP2 as Patient-Tailoring but Not Prognostic Biomarker for Breast Cancer

PurposeTrophoblast cell surface antigen 2 (TROP2) has emerged as a promising target of antibody-drug conjugates (ADCs) for triple-negative breast cancer (TNBC), as well as other breast cancers (BCs). This study aims to investigate the biomarker value of TROP2 for patient-tailoring and prognostic for BC patients, including TNBC.MethodsThe levels of TROP2 expression in 404 Chinese BC tissues on tissue microarrays (TMAs) were quantified by immunohistochemistry and their correlations to the clinicopathological factors and the overall survival rate were analyzed. Also, BC cell lines and patient-derived organoids (PDOs) with different TROP2 expression levels were employed to investigate the correlation between TROP2 expression levels and the therapeutic responses to DS001, a TROP2-directed ADC molecule with stable linker and potent payload.ResultsTROP2 overexpression was identified in significantly more (P = 0.046) tumor tissues (41.08%, 99/241) than normal adjacent tissues (31.29%, 51/163) from Chinese BC patients, and in significantly more (P = 0.024) TNBC patients (59.38%, 19/32) than in other BC types (38.28%, 80/209). BC cell line with the lowest TROP2 expression level failed to respond to DS001 treatment. The levels of TROP2 expression were determined to be significantly correlated with the potencies of DS001 treatment, but not with the overall survival rates of the patients.ConclusionOur results demonstrated that TROP2 could serve as a patient-tailoring and predictive biomarker for ADC therapeutics but not as a general prognostic biomarker to predicate patient survival.

Trophoblast Cell Surface Antigen 2 Expression in Human Tumors: A Tissue Microarray Study on 18,563 Tumors

Introduction: Trophoblast cell surface antigen 2 (TROP2) is the target of sacituzumab govitecan, an antibody-drug conjugate approved for treatment of triple negative breast cancer and urothelial carcinoma. Methods: A tissue microarray containing 18,563 samples from 150 different tumor types and subtypes as well as 608 samples of 76 different normal tissue types was analyzed by TROP2 immunohistochemistry. Results: TROP2 positivity was found in 109 tumor categories, including squamous cell carcinomas of various origins, urothelial, breast, prostate, pancreatic, and ovarian cancers (>95% positive). High TROP2 expression was linked to advanced stage (p = 0.0069) and nodal metastasis (p < 0.0001) in colorectal cancer as well as to nodal metastasis in gastric adenocarcinoma (p = 0.0246) and papillary thyroid cancer (p = 0.0013). Low TROP2 expression was linked to advanced stage in urothelial carcinoma (p < 0.0001), high pT (p = 0.0024), and high grade (p < 0.0001) in breast cancer, as well as with high Fuhrmann grade (p < 0.0001) and pT stage (p = 0.0009) in papillary renal cell carcinomas. Conclusion: TROP2 is expressed in many epithelial neoplasms. TROP2 deregulation can be associated with cancer progression in a tumor-type dependent manner. Since anti-TROP2 cancer drugs have demonstrated efficiency, they may be applicable to a broad range of tumor entities in the future.

TROP-2 and 5hmC expression in follicular-patterned thyroid neoplasm emphasizing tiny well-formed papillae

BackgroundFollicular-patterned thyroid neoplasms (FPTNs), characterized by predominantly follicular growth pattern, represent diverse pathological entities. We aimed to study the nuclear features and the immunoexpression of trophoblast cell-surface antigen 2 (TROP-2) and 5-hydroxymethylcytosine (5hmC) in FPTNs. DesignFPTNs were divided into 4 groups: I) noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP), II) encapsulated follicular variant of papillary thyroid carcinoma (FVPTC) with capsular invasion, III) infiltrative FVPTC, and IV) PTC with a predominantly follicular pattern and well-formed papillae (<1%). Nuclear characteristics were evaluated by image analysis. TROP-2 and 5hmC immunostains were analyzed correlating with histological features using QuPath. ResultsFrom the group I to II, III, and IV, there is a gradual increase in nuclear atypia in terms of the nuclear area, max caliper, perimeter, circularity, and hematoxylin OD means (corresponding to nuclear enlargement, membrane irregularity, and clearing). A similar trend is observed in the TROP-2 expression. 5hmC expression is highly preserved in groups I, II, and III in contrast to a significant loss in group IV. Group IV tumors show more frequent regional lymph node involvement and the highest BRAF V600E mutation rate. ConclusionAmong FPTNs, group IV tumors exhibit the most advanced nuclear atypia, highest TROP-2 expression, significant 5HMC expression loss, frequent regional lymph node involvement, and the highest BRAF V600E mutation rate. Our data further support that the presence of any true papillae should be an exclusion criterion for NIFTP. Therefore, well-formed papillae even if very minute (<1% of the tumor) should not be overlooked.

TROP2 Expression in Sebaceous and Sweat Gland Carcinoma.

Sebaceous carcinoma and sweat gland carcinoma (malignant tumors with apocrine and eccrine differentiation) are rare malignant skin adnexal tumors that differentiate toward sebaceous gland and eccrine and apocrine glands, respectively. Owing to the rarity of these carcinomas, standard treatments for advanced disease have not been established. Because the prognosis of patients with systemic metastasis is poor, a new treatment for these diseases is eagerly desired. Trophoblast cell surface antigen 2 (TROP2) and sacituzumab govitecan, an antibody–drug conjugate of TROP2, have attracted attention in the treatment of various solid tumors. In the current study, we immunohistochemically investigated TROP2 expression in 14 sebaceous carcinoma and 18 sweat gland carcinoma samples and found strong and relatively homogeneous TROP2 staining in both cancer types. The mean Histoscore, a semi-quantitative scoring ranging from 0 (negative) to 300, was 265.5 in sebaceous carcinoma and 260.0 in sweat gland carcinoma. These observations directly suggest that both sebaceous carcinoma and sweat gland carcinoma could be potentially treated with TROP2-targeted antibody–drug conjugates such as sacituzumab govitecan.

The Effect of TROP2 Expression on Papillary Thyroid Carcinoma Development in Iraqi Patients

Background : Papillary Thyroid Carcinoma (PTC) is common type of the thyroid cancers, it’s onset in female at 30-50 years more than male and account for about 80% of all thyroid cancer cases . PTC diagnosis depend on histo-pathological finds of abnormal papillary architectures in the tissue as golden standerd of PTC diagnosis . Trophoblast cell surface antigen 2 (TROP2) is trans-membrane glycoprotein receptor ,encoded by Tacstd2 gene , observe in various cancer types specially epithelial cancers . TROP2 has the up-regulation ( overexpression) in cancer cells such as pancreatic , thyroid and ovarian cancers. Objective of the Study:It’s shown up-regulation of TROP 2 in PTC Iraqi patients by Immunohistochemical method.Materials and Methods: The current study done in Al-Yarmook Teaching Hospital from March 2020 to January 2021 , was included 30 cases of PTC patients and 30 healthy subjects , all of subject’s age were more than 30 years . This study depend on collect of paraffin embedded PTC biopsies then used Immunohistochemical method to examined the present of TROP2 in all cases.Results: This qualitative study shows significant expression of TROP2 in PTC patients compare with control groups .Conclusion: The current study demonstrate effect of TROP2 expression on PTC development

The Role of TROP2 Expression on Progression of Colon Cancer in Iraqi Patients

Colon Cancer (CC) is common type of the intestinal cancers, it's onset in peoples at 50-70 years and high percent in male more than female and account for about 80% of all intestinal cancer cases CC diagnoses depend on histopathological finds of abnormal colon architectures in the tissue as golden standard of CC diagnosis. Trophoblast cell surface antigen 2 (TROP2) or tumor-associated calcium signal transducer 2 (TACSTD2) is a 36-kDa type I transmembrane glycoprotein and exerts dual functions as an oncogene and tumor suppressor in cancer cells is transmembrane glycoprotein receptor, encoded by Tacstd2 gene, observe in various cancer types of especially epithelial cancers. TROP2 has the up-regulation (overexpression) in another cancer cells such as pancreatic, thyroid and ovarian cancers. It is shown up-regulation of TROP 2 in CC Iraqi patients by Immunohistochemical method. The current study done in Al-Yarmook Teaching Hospital from March 2019 to January 2021, was included 30 cases of CC patients ( 23 males and 7 females) and 30 healthy subjects (23 males and 7 females), all of subject's age were more than 50 years. This study depends on collect of paraffin embedded CC biopsies then used Immunohistochemical method to examine the present of TROP2 in all cases. This qualitative study shows significant expression of TROP2 in CC patients compare with control groups. The present study confirm effect of TROP2 expression on CC development.

Trophoblast cell-surface antigen 2 expression in lung cancer patients and the effects of anti-cancer treatments.

Trophoblast cell-surface antigen 2 (TROP2) is expressed on the surface of trophoblast cells and many malignant tumor cells. However, data on TROP2 expression in advanced lung cancer are insufficient, and its changes have not been fully evaluated. We assessed the prevalence and changes in TROP2 expression in patients with lung cancer who received anti-cancer treatments using immunohistochemical (IHC) analysis with an anti-TROP2 antibody (clone: SP295). IHC scores were graded from 0 to 3; grade ≥ 2 was considered positive for TROP2 expression. We defined a difference in IHC score, before and after anti-cancer treatments, as the change in TROP2 expression. Before anti-cancer treatment, TROP2 expression was observed in 89% (143/160) of the patients and was significantly more common in adenocarcinoma and squamous cell carcinoma than in neuroendocrine carcinoma (P < 0.001). After anti-cancer treatment, TROP2 expression was observed in 87% (139/160) of the patients. The distribution of TROP2 expression in post-treatment samples was analogous to that in pre-treatment samples when compared using the Wilcoxon signed-rank test (P = 0.509). However, an increase in TROP2 expression was seen in 19 (12%), and a decrease in 20 (13%) patients. Patients treated with targeted therapy showed significantly higher changes in TROP2 expression (P = 0.019) and thoracic radiotherapy was more likely to increase TROP2 expression than chemotherapy alone. Although some anti-cancer treatments might alter the TROP2 expression, TROP2 was expressed in most lung cancer specimens before and after anti-cancer treatments. These results support the development of TROP2-directed therapy against advanced lung cancer in various treatment lines.

The Role of TROP2 in BCC and Cutaneous SCC: A Clinical and Immunohistochemical Study.

BackgroundNonmelanoma skin cancer (NMSC) mainly includes basal (BCC) and squamous (SCC) cell carcinoma. Trophoblast cell-surface antigen2 (TROP2), a cell–signal transduction, is one of the tumor-related calcium signal transducer gene family. TROP2 was highly expressed in many cancers, however, its role in BCC and SCC has not yet been studied.ObjectiveTo investigate TROP2 immunohistochemical expression in BCC and SCC (lesional and peri-lesional) skin compared to controls and correlates its expression with the clinicopathologic parameters of the studied cases.MethodsThis case–control study included 17 BCC and 15 SCC patients as well as 12 age and sex matched controls. History and clinical examination were completed. Histological examination of skin biopsies was done together with TROP2 immune-staining.ResultsIn the studied BCC and SCC cases, there was a significant stepwise up-regulation of TROP2 H score from control to peri-lesional, ended by lesional epidermis in one hand (p=0.003 for BCC and p<0.001 for SCC) and tumor island in another hand (p=0.001 for BCC and p=0.003 for SCC). TROP2 expression in both BCC and SCC tumor tissues was not affected by any of the studied clinicopathological parameters of the investigated cases.ConclusionTROP2 could have an important role in BCC and SCC pathogenesis. TROP2 targeting may have appraising effect in clinical application in BCC and SCC management.

Clinicopathologic significance of TROP2 and phospho-TROP2 in gastric cancer.

Trophoblast cell-surface antigen 2 (TROP2) is a transmembrane glycoprotein expressed in epithelial cells. Increased TROP2 expression has been reported to be associated with malignant progression in most carcinomas; however, TROP2 has a tumor-suppressive function in certain types of cancer. Since the function of TROP2 is controversial, the present study subsequently aimed to clarify the clinicopathologic significance of TROP2 and pTROP2 expression in human gastric cancer (GC). The cases of 704 patients with GC who underwent gastrectomy were retrospectively analyzed. The expression levels of TROP2 and pTROP2 in each tumor were evaluated by immunohistochemistry. The association between the clinicopathologic features of patients with GC and the levels of TROP2 and pTROP2 in their tumors was analyzed. Increased TROP2 and pTROP2 expression was identified in 330 (46.9%) and 306 (43.5%) of the 704 patients with GC, respectively. Increased TROP2 expression was associated with the histological intestinal type, high tumor invasion depth (T3/T4), lymph node metastasis, lymphatic invasion and venous invasion. By contrast, increased pTROP2 expression was associated with intestinal type, low tumor invasion depth (T1/2), no lymph node metastasis and no lymphatic invasion. Increased TROP2 expression was associated with poorer overall survival (OS) (P<0.01; log rank test), whereas increased pTROP2 expression was significantly associated with improved OS (P<0.01; log rank test). In conclusion, increased expression levels of TROP2, but not pTROP2, may be associated with the metastatic ability of GC, resulting in poor prognosis of patients with GC.

Development and characterization of TrMab‑6, a novel anti‑TROP2 monoclonal antibody for antigen detection in breast cancer.

Trophoblast cell-surface antigen 2 (TROP2) is a type I transmembrane glycoprotein that is overexpressed in a number of cancer types, including triple-negative breast cancer. The current study aimed to develop a highly sensitive and specific monoclonal antibody (mAb) targeting TROP2, which could be used to evaluate TROP2 expression using flow cytometry, western blot analysis and immunohistochemistry by employing the Cell-Based Immunization and Screening (CBIS) method. The established anti-TROP2 mAb, TrMab-6 (mouse IgG2b, κ), detected TROP2 on PA-tagged TROP2-overexpressing Chinese hamster ovary-K1 (CHO/TROP2-PA) and breast cancer cell lines, including MCF7 and BT-474 using flow cytometry. Western blot analysis indicated a 40 kDa band in lysates prepared from CHO/TROP2-PA, MCF7 and BT-474 cells. Furthermore, TROP2 in 57/61 (93.4%) of the breast cancer specimens was strongly detected using immunohistochemical analysis with TrMab-6. In conclusion, the current study demonstrated that TrMab-6 may be a valuable tool for the detection of TROP2 in a wide variety of breast cancer types.

Molecular Profiling Reveals Limited Targetable Biomarkers in Neuroendocrine Carcinoma of the Cervix.

Neuroendocrine carcinoma of the cervix (NEC) is a rare and highly aggressive cervical malignancy. Given that no targeted therapy has been approved specifically to NEC, we investigated the presence of novel, potentially targetable biomarkers in a large cohort of NEC. Sixty-two NEC were molecularly profiled for biomarkers of targeted therapies including antibody-drug conjugates [delta-like canonical notch ligand 3 (DLL3), a trophoblast cell surface antigen 2 (TROP-2), and folate receptor 1 (FOLR1)], NTRK1-3 gene fusions, and immune checkpoint inhibitors [programmed death-ligand 1 (PD-L1), tumor mutational burden, and microsatellite instability] using immunohistochemistry and DNA/RNA next-generation sequencing assays. A cohort of squamous cell carcinomas of the cervix (n=599) was used for comparison for immune-oncology biomarkers. DLL3 expression was observed in 81% of the cases. DLL3 expression was inversely correlated with commonly observed pathogenic mutations in PIK3CA (17%) (P=0.018) and PTEN (10%) (P=0.006). Other more frequently seen pathogenic mutations (TP53 17%, KRAS 11%, and CTNNB1 5%) were not associated with DLL3 expression. TROP-2 expression was detected in only 1 case and no case expressed FOLR1. Although NTRK protein expression was observed in 21% of the cases, none of these had an NTRK gene fusion. PD-L1 expression (10%) and high tumor mutational burden (3%) were significantly less frequent in NEC compared with the squamous cell carcinoma cohort (79% and 11%, respectively). None of the NEC exhibited high microsatellite instability status. Despite frequent DLL3 expression in NEC, a potential therapeutic benefit of DLL3-targeted drugs remains uncertain given the recent failure of the Rova-T therapeutic trial in small cell lung carcinomas. Small cohorts of NEC enriched in PIK3CA/PTEN/AKT and programmed cell death protein 1/PD-L1 alterations indicate therapeutic roles for their respective inhibitors.

MiR-488-3p sponged by circ-0000495 and mediated upregulation of TROP2 in head and neck squamous cell carcinoma development.

TROP2 (trophoblast cell surface antigen 2) overexpression has been reported in many human cancers. The correlation between TROP2 and tumor aggressiveness has implied it could be a prognostic indicator. However, the roles of TROP2 and their underlying mechanisms remain of great interest in head and neck squamous cell carcinoma (HNSCC) biology. In the current study, the prognostic significance of TROP2 in HNSCC archival samples was determined using immunohistochemistry. Quantitative reverse transcriptase PCR (qRT-PCR) was used to measure the phenotypic effects of TROP2 knockdown, miR-488-3p re-expression, and circRNAs expression. Cell viability, migration/invasion as well as in vivo tumor formation assays were accessed. The interactions of miRNAs-TROP2 or circRNAs-miRNAs were determined by qRT-PCR, western blot analysis and luciferase assays. TROP2 was demonstrated overexpression in HNSCC patients and cancer cell lines. High expression of TROP2 was significantly associated with patient relapse. TROP2 promoted tumor cell proliferation, migration, invasion, and tumor growth, through AKT and MAPK pathways. Further investigation revealed that TROP2 is a direct target of miR-488-3p, while circ-0000495 bounds to miR-488-3p. Our study unraveled a novel mechanism by which down-regulation of miR-488-3p sponged by circ-0000495 releases its epigenetic silencing to TROP2. The increased TROP2 promotes tumor proliferation, therefore, providing evidence in support of targeting the circ-0000495/miR-488-3p/TROP2 axis in contributing to HNSCC therapy and preventing tumor metastasis.

TROP2 increases growth and metastasis of human oral squamous cell carcinoma through activation of the PI3K/Akt signaling pathway.

Most malignant neoplasms of the oral cavity are oral squamous cell carcinoma (OSCC), which is a type of highly malignant tumor with a propensity for forming distant metastases. Trophoblast cell surface antigen 2 (TROP2) is a transmembrane protein that is overexpressed in several types of tumor cells, although its role and regulatory mechanism in OSCC have not been determined. The aim of the present study was to examine the effects of TROP2 in human OSCC cell lines. The present study demonstrated that TROP2 protein expression was upregulated in OSCC cell lines. Transfection of short hairpin RNA (shRNA) targeting TROP2 (sh-TROP2) reduced cell proliferation, migration and invasion of OSCC cell lines, whereas overexpression of TROP2 increased proliferation, migration and invasion. sh-TROP2 transfection in OSCC cell lines inhibited tumor growth in OSCC mouse models. Furthermore, TROP2 expression activated the phosphoinositide 3-kinase (PI3K)/Akt signaling pathway in human OSCC cells. These results suggest that TROP2 induces cell growth, migration and invasion through activation of the PI3K/Akt signaling pathway in OSCC cells.

The diagnostic significance of trophoblast cell-surface antigen-2 expression in benign and malignant thyroid lesions.

Thyroid cancers are the most common malignancy of the endocrine system. Over-expression of trophoblast cell-surface antigen 2 (TROP-2) in various tumors has been found to correlate with poor prognosis and aggressive tumor behavior. The aim of this study was to evaluateTROP-2 expression in thyroid neoplasms. This study contained 152 cases, including 48 follicular nodular disease (FND), 29 follicular adenoma (FA), 57 papillary thyroid carcinoma (PTC), 12 follicular thyroid carcinoma (FTC), 3 medullary thyroid carcinoma (MTC), 2 poorly differentiated thyroid carcinoma (PDTC) and 1 undifferentiated thyroid carcinoma (UDTC). TROP-2 expression was investigated via immunohistochemistry in sections prepared from paraffin blocks of the cases. The cases comprised 32 (21%) males and 120 (79%) females with a mean age of 46.8 years (range, 15-85 years). TROP-2 expression was observed in 74.6% of the malignant lesions of the thyroid except for medullary carcinoma, poorly differentiated and undifferentiated thyroid carcinoma. Immunoreactivity was 3.4% in FA, 41.7% of cases with FTC and 81.8% in PTC follicular variant (PTC fv). The difference between FA/FTC and FA/PTC follicular variant were both significant (P < 0.005, P < 0.001, respectively). There was no difference between FTC/PTC fv (P = 0.089). TROP-2 can be considered a useful marker for distinguishing PTC fv cases from follicular nodular disease and follicular adenoma cases because of its high sensitivity in the identification of papillary carcinomas of the thyroid.