Trop2 is overexpressed in gastric cancer and predicts poor prognosis

State-of-the-Art Advancements in Gastroesophageal Cancer Treatment: Harnessing Biomarkers for Precision Care

Gastroesophageal cancers (GECs) represent a significant clinical challenge. For early resectable GEC, the integration of immune checkpoint inhibitors into the perioperative chemotherapy and chemoradiation treatment paradigms are being explored and showing promising results. Frontline management of metastatic GEC is exploring the role of targeted therapies beyond PD-1 inhibitors, including anti-human epidermal growth factor receptor 2 agents, Claudin 18.2 inhibitors, and FGFR2 inhibitors, which have shown considerable efficacy in recent trials. Looking ahead, ongoing trials and emerging technologies such as bispecific antibodies, antibody-drug conjugates, and adoptive cell therapies like chimeric antigen receptor T cells are expected to define the future of GEC management. These advancements signify a paradigm shift toward personalized and immunotherapy-based approaches, offering the potential for improved outcomes and reduced toxicity for patients with GEC.

Cytotoxicity of fourth-generation anti-Trop2 CAR-T cells against breast cancer

The treatment of breast cancer (BC) remains a formidable challenge due to the emergence of drug resistance, necessitating the exploration of innovative strategies. Chimeric antigen receptor (CAR)-T cell therapy, a groundbreaking approach in hematologic malignancies, is actively under investigation for its potential application in solid tumors, including BC. Trophoblast cell surface antigen 2 (Trop2) has emerged as a promising immunotherapeutic target in various cancers and is notably overexpressed in BC. To enhance therapeutic efficacy in BC, a fourth-generation CAR (CAR4) construct was developed. This CAR4 design incorporates an anti-Trop2 single-chain variable fragment (scFv) fused with three costimulatory domains -CD28/4-1BB/CD27, and CD3ζ. Comparative analysis with the conventional second-generation CAR (CAR2; 28ζ) revealed that anti-Trop2 CAR4 T cells exhibited heightened cytotoxicity and interferon-gamma (IFN-γ) production against Trop2-expressing MCF-7 cells. Notably, anti-Trop2 CAR4-T cells demonstrated superior long-term cytotoxic functionality and proliferative capacity. Crucially, anti-Trop2 CAR4-T cells displayed specific cytotoxicity against Trop2-positive BC cells (MDA-MB-231, HCC70, and MCF-7) in both two-dimensional (2D) and three-dimensional (3D) culture systems. Following antigen-specific killing, these cells markedly secreted interleukin-2 (IL-2), tumor necrosis factor-alpha (TNF-α), IFN-γ, and Granzyme B compared to non-transduced T cells. This study highlights the therapeutic potential of anti-Trop2 CAR4-T cells in adoptive T cell therapy for BC, offering significant promise for the advancement of BC treatment strategies.

CEACAM5 and TROP2 define metaplastic and dysplastic transitions in human antral gastric precancerous lesions and tumors

BACKGROUND

Mucosal gastric atrophy and intestinal metaplasia (IM) increase the risk for the development of gastric cancer (GC) as they represent a field for development of dysplasia and intestinal-type gastric adenocarcinoma.

METHODS

We have investigated the expression of two dysplasia markers, CEACAM5 and TROP2, in human antral IM and gastric tumors to assess their potential as molecular markers.

RESULTS

In the normal antral mucosa, weak CEACAM5 and TROP2 expression was only observed in the foveolar epithelium, while inflamed antrum exhibited increased expression of both markers. Complete IM exhibited weak CEACAM5 expression at the apical surface, but no basolateral TROP2 expression. On the other hand, incomplete IM demonstrated high levels of both CEACAM5 and TROP2 expression. Notably, incomplete IM with dysplastic morphology (dysplastic incomplete IM) exhibited higher levels of CEACAM5 and TROP2 expression compared to incomplete IM without dysplastic features (simple incomplete IM). In addition, dysplastic incomplete IM showed diminished SOX2 and elevated CDX2 expression compared to simple incomplete IM. CEACAM5 and TROP2 positivity in incomplete IM was similar to that of gastric adenomas and GC. Significant association was found between CEACAM5 and TROP2 positivity and histology of GC.

CONCLUSIONS

These findings support the concept that incomplete IM is more likely associated with GC development. Overall, our study provides evidence of the heterogeneity of gastric IM and the distinct expression profiles of CEACAM5 and TROP2 in dysplastic incomplete IM. Our findings support the potential use of CEACAM5 and TROP2 as molecular markers for identifying individuals with a higher risk of GC development in the context of incomplete IM.

An electrochemical biosensor to assay Trop-2 of breast cancer cells fabricated by methylene blue-assisted assembly of DNA nanoparticles

Human trophoblast surface cell antigen 2 (Trop-2) on the tumor cell membrane can not only serve as the target for chemotherapy drugs, but also as a biomarker for typing and prognosis of breast cancer; however, assay of Trop-2 is seriously hampered due to the limitations of available tool. Herein, we have designed and fabricated an electrochemical biosensor for the assay of Trop-2 based on methylene blue (MB)-assisted assembly of DNA nanocomposite particles (DNPs). Specially, the recognition between Trop-2 and its aptamer may activate the primer exchange reaction (PER) on an electrode surface to produce long single-strand DNA (ssDNA) which can be self-assembled into DNPs by electrostatic interaction between negative charged DNA and positive charged and electro-active MB molecules which can also be used to give electrochemical signal. By using this electrochemical biosensor, ultrasensitive detection of tumor cells with high Trop-2 expressions can be conducted, with the limit of detection (LOD) of 1 cell/mL. Moreover, this biosensor can be further used for accurately profiling Trop-2 expression of tumor cells in mouse tissues, suggesting its great potential in the precise definition of breast cancer.

Immunohistochemical expression of TROP‑2 (TACSTD2) on the urothelial carcinoma of the urinary bladder and other types of cancer

In metastatic or locally advanced urothelial carcinoma (UC), therapeutic options have been limited to chemotherapy and immune checkpoint inhibitors. Novel targets and drugs such as antibody drug conjugates have been developed, and enfortumab vedotin targeting nectin-4 and sacituzumab govitecan (SG) targeting trophoblast cell surface antigen 2 (TROP-2), the protein product of the TACSTD2 gene, have been approved. The expression of TROP-2 was investigated within UC and other types of carcinomas, and within the tissue of different healthy organs to understand treatment responses and toxicities. The expression of TROP-2 in the tissues of 42 patients with UC, 13 patients with other types of cancer and in the normal tissues of 11 patients was retrospectively analyzed. Immunohistochemical staining of the TROP-2 protein was performed on a BenchMark ULTRA IHC/ISH System (Roche Tissue Diagnostics; Roche Diagnostics, Ltd.) according to accredited staining protocols in a routine immunohistochemistry accredited and certified facility of the laboratory of immunohistochemistry at the Institute of Pathology (Gerhard-Domagk Institute)- University Hospital Muenster (UKM)-Muenster-Germany]. Different expression levels of TROP-2 were observed, and the highest expression rate of TROP-2 was observed in UC, independent of the tumor stage. However, normal urothelial cells had similar expression levels. Except for ductal carcinoma in situ, the expression of TROP-2 was reduced in other types of cancer and in the healthy tissues from other organs, including pancreas, gall bladder, colon and prostate. Given the treatment response based on the expression level of TROP-2, SG would be effective in almost all cases of UC. However, it would also have an effect on the normal urothelium.

An assembly of TROP2-mediated signaling events

Trophoblast cell surface antigen 2 (TROP2) is a calcium-transducing transmembrane protein mainly involved in embryo development. The aberrant expression of TROP2 is observed in numerous cancers, including triple-negative breast cancer, gastric, colorectal, pancreatic, squamous cell carcinoma of the oral cavity, and prostate cancers. The main signaling pathways mediated by TROP2 are calcium signaling, PI3K/AKT, JAK/STAT, MAPKs, and β-catenin signaling. However, collective information about the TROP2-mediated signaling pathway is not available for visualization or analysis. In this study, we constructed a TROP2 signaling map with respect to its role in different cancers. The data curation was done manually by following the NetPath annotation criteria. The described map consists of different molecular events, including 8 activation/inhibition, 16 enzyme catalysis, 19 gene regulations, 12 molecular associations, 39 induced-protein expressions, and 2 protein translocation. The data of the TROP2 pathway map is made freely accessible through the WikiPathways Database ( https://www.wikipathways.org/index.php/Pathway:WP5300 ). Development of TROP2 signaling pathway map.

Prognostic significance of trophoblastic cell surface antigen 2 expression and pathologic parameters in patients with ampullary adenocarcinoma

Trophoblastic cell surface antigen 2 (TROP2) has been reported to be up-regulated in several types of carcinomas and is associated with aggressive behavior and poor survival. However, TROP2 expression and its clinical significance in ampullary adenocarcinoma (AA) have not been investigated. We examined TROP2 expression by immunohistochemistry in 112 patients with AAs. The associations of TROP2 expression with clinicopathologic characteristics were evaluated by χ2 analyses or Fisher's exact tests. The associations of TROP2 expression and pathologic parameters with survival were evaluated by the Kaplan-Meier method and univariate and multivariate Cox regression analyses. Eighty-six AAs (76.8%) were positive for TROP2, which showed a membranous and cytoplasmic staining. TROP2 expression was associated with higher frequency (P = .04) and higher number (P = .03) of lymph node metastasis, higher pN stage (P = .03), less frequent adenoma (P = .04), and higher frequency of recurrence/metastasis (P = .004). TROP2 expression was associated with shorter disease-free survival (P = .02) and overall survival (P = .03). TROP2 expression was an independent prognostic factor for disease-free survival (P = .04). We demonstrated that TROP2 was expressed in 76.8% of AAs. TROP2 expression was associated with higher frequency and high number of lymph node metastasis and higher pN stage. More importantly, TROP2 expression was associated with higher frequency of recurrence/metastasis, shorter disease-free and overall survival and was an independent prognostic factor for disease-free survival. Our results suggest that TROP2 may be used both as a prognostic marker and as a therapeutic target for patients with AAs.

Efficacy, Safety, and Challenges of CAR T-Cells in the Treatment of Solid Tumors

Immunotherapy has been the fifth pillar of cancer treatment in the past decade. Chimeric antigen receptor (CAR) T-cell therapy is a newly designed adoptive immunotherapy that is able to target and further eliminate cancer cells by engaging with MHC-independent tumor-antigens. CAR T-cell therapy has exhibited conspicuous clinical efficacy in hematological malignancies, but more than half of patients will relapse. Of note, the efficacy of CAR T-cell therapy has been even more disappointing in solid tumors. These challenges mainly include (1) the failures of CAR T-cells to treat highly heterogeneous solid tumors due to the difficulty in identifying unique tumor antigen targets, (2) the expression of target antigens in non-cancer cells, (3) the inability of CAR T-cells to effectively infiltrate solid tumors, (4) the short lifespan and lack of persistence of CAR T-cells, and (5) cytokine release syndrome and neurotoxicity. In combination with these characteristics, the ideal CAR T-cell therapy for solid tumors should maintain adequate T-cell response over a long term while sparing healthy tissues. This article reviewed the status, clinical application, efficacy, safety, and challenges of CAR T-cell therapies, as well as the latest progress of CAR T-cell therapies for solid tumors. In addition, the potential strategies to improve the efficacy of CAR T-cells and prevent side effects in solid tumors were also explored.

Trop-2 as a Therapeutic Target in Breast Cancer

The emergence of Trop-2 as a therapeutic target has given rise to new treatment paradigms for the treatment of patients with advanced and metastatic breast cancer. Trop-2 is most highly expressed in triple negative breast cancer (TNBC), but the receptor is found across all breast cancer subtypes. With sacituzumab govitecan, the first FDA-approved, Trop-2 inhibitor, providing a survival benefit in patients with both metastatic TNBC and hormone receptor positive breast cancer, additional Trop-2 directed therapies are under investigation. Ongoing studies of combination regimens with immunotherapy, PARP inhibitors, and other targeted agents aim to further harness the effect of Trop-2 inhibition. Current investigations are also underway in the neoadjuvant and adjuvant setting to evaluate the therapeutic benefit of Trop-2 inhibition in patients with early stage disease. This review highlights the significant impact the discovery Trop-2 has had on our patients with heavily pretreated breast cancer, for whom few treatment options exist, and the future direction of novel Trop-2 targeted therapies.

Advances in Trop2-targeted therapy: Novel agents and opportunities beyond breast cancer

Trop2 is a transmembrane glycoprotein and calcium signal transducer with limited expression in normal human tissues. It is consistently overexpressed in a variety of malignant tumors and participates in several oncogenic signaling pathways that lead to tumor development, invasion, and metastasis. As a result, Trop2 has become an attractive therapeutic target in cancer treatment. The anti-Trop2 antibody-drug conjugate (Trodelvy™, sacituzumab govitecan) has been approved to treat metastatic triple-negative breast cancer. However, it is still unclear whether the success observed in Trop2-positive breast cancer could be replicated in other tumor types, owing to the differences in the expression levels and functions of Trop2 across cancer types. In this review, we summarize the recent progress on the structures and functions of Trop2 and highlight the potential diagnostic and therapeutic value of Trop2 beyond breast cancer. In addition, the promising novel Trop2-targeted agents in the clinic were discussed, which will likely alter the therapeutic landscape of Trop2-positive tumors in the future.

Signaling pathways and therapeutic interventions in gastric cancer

Gastric cancer (GC) ranks fifth in global cancer diagnosis and fourth in cancer-related death. Despite tremendous progress in diagnosis and therapeutic strategies and significant improvements in patient survival, the low malignancy stage is relatively asymptomatic and many GC cases are diagnosed at advanced stages, which leads to unsatisfactory prognosis and high recurrence rates. With the recent advances in genome analysis, biomarkers have been identified that have clinical importance for GC diagnosis, treatment, and prognosis. Modern molecular classifications have uncovered the vital roles that signaling pathways, including EGFR/HER2, p53, PI3K, immune checkpoint pathways, and cell adhesion signaling molecules, play in GC tumorigenesis, progression, metastasis, and therapeutic responsiveness. These biomarkers and molecular classifications open the way for more precise diagnoses and treatments for GC patients. Nevertheless, the relative significance, temporal activation, interaction with GC risk factors, and crosstalk between these signaling pathways in GC are not well understood. Here, we review the regulatory roles of signaling pathways in GC potential biomarkers, and therapeutic targets with an emphasis on recent discoveries. Current therapies, including signaling-based and immunotherapies exploited in the past decade, and the development of treatment for GC, particularly the challenges in developing precision medications, are discussed. These advances provide a direction for the integration of clinical, molecular, and genomic profiles to improve GC diagnosis and treatments.

TROP2 is a Good Indicator for Infiltrative Nature of Carcinoma Rather than Diagnosing Malignancy in Thyroid

TROP2 is a glycoprotein which is expressed in carcinomas rather than normal tissues and associated with poor prognosis. Immunohistohemical TROP2 staining was determined to be useful for diagnosing papillary thyroid carcinoma (PTC). In this study, we aimed to find out relationship between TROP-2 expression and the diagnosis of PTC, and clinico pathological parameters. This retrospective study was conducted on 270 cases (145 malignant and 124 benign). All histopathological parameters were re-evaluated blindly. We used 3 different scores for positivity for TROP2 expression (TES: Total estimation score, 5%, IRS:Immunoreactive score). Sensitivity was respectively according to TES, 5%and IRS; 55.5%, 54.1%, 51.4%. Specificity was 98.4% in all different scores. TROP2 positivity was correlated with older age in 5% score and TES. Absence of encapsulation, presence of infiltrating spreading, perineural invasion, extra thyroidal extension, tall cell and/or hobnail differentiation were associated with TROP2 expression in three different scores. Presence of lymphatic invasion was correlated with TROP2 positivity in 5% score and IRS. TROP2 expression was inversely proportional to follicular variant PTC and tumour size in 5% score. TROP-2 is a marker for aggressive behaviour rather than detecting malignancy, but if it stained and not malignant, it may also have potential for determining precursor lesion that demands further studies. Additionally, in 3 different scores, TES was most sensitive, but most variable that had correlation with TROP2 was seen at 5% score.

Curcumin in the treatment of urological cancers: Therapeutic targets, challenges and prospects

Urological cancers include bladder, prostate and renal cancers that can cause death in males and females. Patients with urological cancers are mainly diagnosed at an advanced disease stage when they also develop resistance to therapy or poor response. The use of natural products in the treatment of urological cancers has shown a significant increase. Curcumin has been widely used in cancer treatment due to its ability to trigger cell death and suppress metastasis. The beneficial effects of curcumin in the treatment of urological cancers is the focus of current review. Curcumin can induce apoptosis in the three types of urological cancers limiting their proliferative potential. Furthermore, curcumin can suppress invasion of urological cancers through EMT inhibition. Notably, curcumin decreases the expression of MMPs, therefore interfering with urological cancer metastasis. When used in combination with chemotherapy agents, curcumin displays synergistic effects in suppressing cancer progression. It can also be used as a chemosensitizer. Based on pre-clinical studies, curcumin administration is beneficial in the treatment of urological cancers and future clinical applications might be considered upon solving problems related to the poor bioavailability of the compound. To improve the bioavailability of curcumin and increase its therapeutic index in urological cancer suppression, nanostructures have been developed to favor targeted delivery.

Recently approved treatment options for patients with metastatic triple-negative and HER2-neu-positive breast cancer

Breast cancer (BC) is the most common cancer affecting women worldwide. In 2021, the estimated number of new breast cancer cases was 281 550 and about 43 500 women died from metastatic breast cancer (mBC). For women aged 20-59 years, mBC remains the leading cause of cancer death and is, therefore, an important public health concern. Only 5% of women initially present with metastatic disease. Approximately 20% of patients presenting with local or locoregional disease progress to mBC despite adjuvant therapy. Inspite of all the medicosurgical advancements, the overall prognosis for patients diagnosed with mBC remains poor, with median overall survival of approximately 31 months, although this varies based on tumor biology. In recent years, there has been significant progress in developing immunotargeted therapies such as antihuman epidermal growth factor receptor 2 (anti-HER2) or check point inhibitors that confirmed to have dramatically improve the prognosis of mBC, a historically unfavorable disease subset. Even with the major progress that has been made in understanding the biology of BC, challenges such as resistance frequency to therapies, unknown efficacy, concerns for safety of drug combination and toxicities still remain high. Therefore, a new targeted and more selective treatment approaches are the need of the hour. In this review, we aim to outline the most recently approved medications in treatment of Her2-positive and triple-negative breast cancers.

Selection of Payloads for Antibody-Drug Conjugates Targeting Ubiquitously Expressed Tumor-Associated Antigens: a Case Study

The main objective of this work was to demonstrate which kind of payload is the suitable choice for antibody-drug conjugates directed to widely expressed tumor-associated antigen. Trop-2 is overexpressed in various solid tumors, but it is also present on the epithelium of several normal tissues. A well-designed anti-Trop-2 ADC demands a good balance of efficacy and toxicity. In this research, MMAE, SN-38, and DXd were selected as candidates for payloads of the anti-Trop-2 mAb SY02. The antitumor activities and safety profiles of these ADCs were investigated to compare the therapeutic windows. Robust in vitro cytotoxicity was observed on human pancreatic cancer cell CFPAC-1 and breast cancer cell MDA-MB-468 with IC₅₀ generally in the subnanomolar range. Consistent with in vitro assay, SY02-DXd and SY02-SN-38 demonstrated superior efficacy in CFPAC-1 xenograft models with TGI rates of 98.2% and 87.3%, respectively. However, SY02-MMAE could hardly inhibit the tumor growth. Subsequently, antitumor activities of these ADCs were further compared in MDA-MB-468 xenograft model. Complete tumor regression was observed in SY02-DXd and SY02-MMAE groups, indicating their potent antitumor activities. In an exploratory safety and pharmacokinetic study, SY02-DXd demonstrated the best safety profile with minimal adverse events in cynomolgus monkeys, while SY02-MMAE exhibited severe on-target skin toxicity which caused death. In conclusion, SY02-DXd demonstrated superior efficacy and safety with the widest therapeutic window. Based on the efficacy and safety results, moderate cytotoxic payloads would be ideal choices for ADCs targeting ubiquitously expressed antigens.

TROP2 Down-Regulated DSG2 to Promote Gastric Cancer Cell Invasion and Migration by EGFR/AKT and DSG2/PG/β-Catenin Pathways

AIMS

Explore the specific mechanism of TROP2 in promoting cancer in gastric cancer, and provide a basis for the prevention and treatment of gastric cancer. Background Gastric cancer (GC) is the fourth most commonly found cancer and the second highest cause of cancer related death worldwide, TROP2 overexpression is closely related with many cancers including gastrointestinal tumors, DSG2 is an important protein in cell adhesion and its loss is related to cell migration.

OBJECTIVE

Explore the specific mechanism of TROP2 in promoting cancer in gastric cancer, and provide a basis for the prevention and treatment of gastric cancer.

METHOD

DSG2 was identified as an interacting protein of TROP2 in GC cells by co-immunoprecipitation and mass spectrometry. The regulated behavior of TROP2 on DSG2 expression was investigated with TROP2 over-expressure or knockdown. Cell-cell adhesion capacity medicated by DSG2 was evaluated by adhesion related assays. Electron microscope observation was utilized for accessing GC tumor desmosome assembly. Proteins in EGFR/AKT and DSG2/PG/β-catenin pathways were evaluated by western blotting.

RESULT

This study suggests that abundant expression of TROP2 in GC cells lessened DSG2 levels as well as desmosome adhesion, increased cell invasion, migration and promoted malignant progression through EGFR/AKT and DSG2/PG/β-catenin pathways.

CONCLUSION

TROP2 promotes gastric cancer cell invasion and migration by decreasing DSG2 expression through EGFR/AKT and DSG2/PG/β-catenin pathways.

Positive H. pylori status predicts better prognosis of non-cardiac gastric cancer patients: results from cohort study and meta-analysis

BACKGROUND

Previous researches have associated Helicobacter pylori (H. pylori) with a prognosis of gastric cancer (GC), however, without a concert conclusion. This study aimed to study this issue further by a prospective cohort study and a meta-analysis.

METHODS

Histologically diagnosed gastric cancer (GC) patients were recruited into the primary prospective cohort study between January 2009 to December 2013. All the patients were followed-up periodically to record information on post-surgery therapy and overall survival status. The pre-surgery status of H. pylori was measured by enzyme-linked immunosorbent assay. A meta-analysis was conducted after retrieving related researches in the databases of PubMed and Embase up to April 2020. Pooled hazard ratios (HRs) and 95% confidence intervals (CIs) were summarized to validate the relationship between H. pylori infection and the survival time of GC patients. I² statistics and Q test were used to assess the heterogeneity. Sensitivity analyses were performed using Galbraith's plot, leave-one-out analysis, subgroup analyses and meta-regression to explore the sources of heterogeneity and the stability of the summary results.

RESULTS

A total of 743 GC patients with radical tumorectomy were included prospectively and 516 (69.4%) were positive on H. pylori. H. pylori-positive patients tended to survive longer than -negative ones (HR 0.92, 95%CI: 0.74-1.15), though the tendency was not statistically significant. Cohort studies on the prognosis of GC were retrieved comprehensively by assessing the full-text and 59 published studies, together with the result of our study, were included in the further meta-analysis. The summarized results related the positive status of H. pylori to better overall survival (HR 0.81, 95%CI: 0.72-0.90) and disease-free survival (HR 0.83, 95%CI: 0.67-0.99). Results from subgroup analyses indicated that the pooled magnitude of this association was relatively lower in studies not referring to H. pylori in title and abstract.

CONCLUSIONS

In conclusion, gastric cancer patients with H. pylori have a better prognosis than patients of H. pylori negative. More stringent surveillance strategies may be necessary for patients with H. pylori negative at cancer diagnosis.

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.

Oncogene-mediated metabolic gene signature predicts breast cancer outcome

Breast cancer remains the second most lethal cancer among women in the United States and triple-negative breast cancer is the most aggressive subtype with limited treatment options. Trop2, a cell membrane glycoprotein, is overexpressed in almost all epithelial cancers. In this study, we demonstrate that Trop2 is overexpressed in triple-negative breast cancer (TNBC), and downregulation of Trop2 delays TNBC cell and tumor growth supporting the oncogenic role of Trop2 in breast cancer. Through proteomic profiling, we discovered a metabolic signature comprised of TALDO1, GPI, LDHA, SHMT2, and ADK proteins that were downregulated in Trop2-depleted breast cancer tumors. The identified oncogene-mediated metabolic gene signature is significantly upregulated in TNBC patients across multiple RNA-expression clinical datasets. Our study further reveals that the metabolic gene signature reliably predicts poor survival of breast cancer patients with early stages of the disease. Taken together, our study identified a new five-gene metabolic signature as an accurate predictor of breast cancer outcome.

Recent advances in trophoblast cell-surface antigen 2 targeted therapy for solid tumors

Trophoblast cell-surface antigen 2 (Trop 2) is a transmembrane glycoprotein that is highly expressed in various cancer types with relatively low or no baseline expression in most normal tissues. Its overexpression is associated with tumor growth and poor prognosis; Trop 2 is, therefore, an ideal therapeutic target for epithelial cancers. Several Trop 2 targeted therapeutics have recently been developed for the treatment of cancers, such as anti-Trop 2 antibodies and antibody-drug conjugates (ADCs), as well as Trop 2-specific cell therapy. In particular, the safety and clinical benefit of Trop 2-based ADCs have been demonstrated in clinical trials across multiple tumor types, including those with limited treatment options, such as triple-negative breast cancer, platinum-resistant urothelial cancer, and heavily pretreated non-small cell lung cancer. In this review, we elaborate on recent advances in Trop 2 targeted modalities and provide an overview of novel insights for future developments in this field.

Trop2 Expression in Extramammary Paget's Disease and Normal Skin

Extramammary Paget's disease (EMPD) is a rare skin cancer arising in the apocrine gland-rich areas. Most EMPD tumors are dormant, but metastatic lesions are associated with poor outcomes owing to the lack of effective systemic therapies. Trophoblast cell surface antigen 2 (Trop2), a surface glycoprotein, has drawn attention as a potential therapeutic target for solid tumors. Sacituzumab govitecan, an antibody-drug conjugate of Trop2, has recently entered clinical use for the treatment of various solid cancers. However, little is known about the role of Trop2 in EMPD. In this study, we immunohistochemically examined Trop2 expression in 116 EMPD tissue samples and 10 normal skin tissues. In normal skin, Trop2 was expressed in the epidermal keratinocytes, inner root sheaths, and infundibulum/isthmus epithelium of hair follicles, eccrine/apocrine glands, and sebaceous glands. Most EMPD tissues exhibited homogeneous and strong Trop2 expression, and high Trop2 expression was significantly associated with worse disease-free survival (p = 0.0343). These results suggest the potential use of Trop2-targeted therapy for EMPD and improve our understanding of the skin-related adverse effects of current Trop2-targeted therapies such as sacituzumab govitecan.

CORO1C is Associated With Poor Prognosis and Promotes Metastasis Through PI3K/AKT Pathway in Colorectal Cancer

Trophoblast cell surface protein 2 (Trop2) is one of the cancer-related proteins that plays a vital role in biological aggressiveness and poor prognosis of colorectal cancer (CRC). The study of the Trop2 related network is helpful for us to understand the mechanism of tumorigenesis. However, the effects of the related proteins interacting with Trop2 in CRC remain unclear. Here, we found that coronin-like actin-binding protein 1C (CORO1C) could interact with Trop2 and the expression of CORO1C in CRC tissues was higher than that in paracarcinoma tissues. The expression of CORO1C was associated with histological type, lymph node metastasis, distant metastasis, AJCC stage, venous invasion, and perineural invasion. The correlation between CORO1C expression and clinical characteristics was analyzed demonstrating that high CORO1C expression in CRC patients were associated with poor prognosis. Furthermore, CORO1C knockdown could decrease the cell proliferation, colony formation, migration and invasion in vitro and tumor growth in vivo. The underlying mechanisms were predicted by bioinformatics analysis and verified by Western blotting. We found that PI3K/AKT signaling pathway was significantly inhibited by CORO1C knockdown and the tuomr-promoting role of CORO1C was leastwise partly mediated by PI3K/AKT signaling pathway. Thus, CORO1C may be a valuable prognostic biomarker and drug target in CRC patients.

FIS1 Overexpression Is Correlated with Tumor Metastasis in Gastric Adenocarcinoma

BACKGROUND

Due to poor prognosis and treatment failure, gastric cancer (GC) is still regarded as one of the deadliest malignancies worldwide, demanding new molecular targets for therapeutic and diagnostic approaches. Therefore, the current study was aimed to investigate the expression levels of FIS1 gene involving in mitochondrial fission as a promising target in gastric tumor progression.

MATERIAL AND METHODS

A total of eighty clinical tissue samples including 40 gastric primary tumor samples and 40 paired marginal samples were prepared. Total RNA was extracted and reverse transcribed to complementary DNA. Then, FIS1 expression levels were quantified in GC samples compared to normal ones using q-PCR. Furthermore, the correlation between FIS1 expression and clinicopathological features of patients was evaluated.

RESULTS

The obtained results illustrated that FIS1 is significantly (p = 0.0013) overexpressed in gastric tumors compared to noncancerous marginal tissues; indicating the possible role of FIS1 through gastric tumorigenesis. Further analysis showed that FIS1 upregulation was significantly (p = 0.0419) correlated with metastasis in patients. Also, ROC curve analysis estimated an area under the curve (AUC) value of 0.7209 for FIS1 to discriminate cancer patients from healthy cases.

CONCLUSION

Taken together, our findings suggested FIS1 as a promising tumor marker where its overexpression predicts tumor metastasis of gastric cancer.

DNA methylation of tumor associated calcium signal transducer 2 (TACSTD2) loci shows association with clinically aggressive renal cell cancers

Background

DNA methylation is frequently observed in the development and progression of many human tumors as well as renal cell cancer (RCC). Tumor Associated Calcium Signal Transducer 2 (TACSTD2) participates in cell cycle progression through MAPK signalling pathway activation. Moreover, tumor-specific hypermethylation and association with aggressive cancer characteristics has been found for lung adenocarcinoma, hepatocellular carcinoma and cholangiocarcinoma. Whether TACSTD2 is tumor specifically hypermethylated in RCC or shows association of methylation with adverse clinicopathological parameters and survival of patients has not been investigated at yet.

Methods

Quantitative methylation-specific PCR (qMSP) analysis of a locus in the intron 1 region of TACSTD2 gene was carried out in a cross-sectional study of 127 paired RCC and normal samples. In silico analysis of TACSTD2 methylation in the TCGA Kidney Renal Clear Cell Carcinoma (KIRC) dataset of 280 patients served as validation cohort. Statistical analyses were carried out using the two-sided paired t-test for matched tumor and normal sample comparisons, logistic regression for subgroup comparisons, Cox regression for analysis of recurrence free survival (RFS) and Pearson correlation analysis for correlation of TACSTD2 methylation and TACSTD2 mRNA in KIRC data.

Results

Higher methylation levels in RCC were significantly associated with advanced disease (p < 0.001), high tumor stage (p = 0.003), tumor differentiation (p = 0.033) and presence of lymph node (p = 0.021) or distant metastases (p = 0.008). TACSTD2 hypermethylation was associated with a shorter RFS of patients and demonstrate statistical independency from clinical parameters as state of metastasis, tumor stage, grade and state of advanced disease. In silico validation using TCGA KIRC data also demonstrated association of TACSTD2 loci with adverse clinicopathology and shortened RFS of patients. In addition, in silico analyses of TCGA KIRC data showed an inverse correlation between DNA methylation levels of TACSTD2 and mRNA expression.

Conclusions

Our results suggest an association between TACSTD2 methylation and disease progression and clinical course of RCC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-08172-1.

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.

Toxicarioside O Inhibits Cell Proliferation and Epithelial-Mesenchymal Transition by Downregulation of Trop2 in Lung Cancer Cells

Toxicarioside O (TCO), a natural product derived from Antiaris toxicaria, has been identified to be a promising anticancer agent. In this study, we aimed to investigate the effect of TCO on the proliferation and epithelial-mesenchymal transition (EMT) of lung cancer cells and its molecular mechanisms. Here, we indicated that TCO inhibits the proliferation of lung cancer cells both in vitro and in vivo. Our results demonstrated that TCO induces apoptosis in lung cancer cells. Moreover, we found that TCO suppresses EMT program and inhibits cell migration in vitro. Mechanistically, TCO decreases the expression of trophoblast cell surface antigen 2 (Trop2), resulting in inhibition of the PI3K/Akt pathway and EMT program. Overexpression of Trop2 rescues TCO-induced inhibition of cell proliferation and EMT. Our findings demonstrate that TCO markedly inhibits cell proliferation and EMT in lung cancer cells and provides guidance for its drug development.

Trop2: Jack of All Trades, Master of None

Trophoblast cell surface antigen 2 (Trop2) is a widely expressed glycoprotein and an epithelial cell adhesion molecule (EpCAM) family member. Although initially identified as a transmembrane protein, other subcellular localizations and processed forms were described. Its congenital mutations cause a gelatinous drop-like corneal dystrophy, a disease characterized by loss of barrier function in corneal epithelial cells. Trop2 is considered a stem cell marker and its expression associates with regenerative capacity in various tissues. Trop2 overexpression was described in tumors of different origins; however, functional studies revealed both oncogenic and tumor suppressor roles. Nevertheless, therapeutic potential of Trop2 was recognized and clinical studies with drug-antibody conjugates have been initiated in various cancer types. One of these agents, sacituzumab govitecan, has been recently granted an accelerated approval for therapy of metastatic triple-negative breast cancer. In this article, we review the current knowledge about the yet controversial function of Trop2 in homeostasis and pathology.

Molecular biology and immunology of gastric cancer peritoneal metastasis

Peritoneal metastases occur in 55-60% of patients with gastric cancer (GC) and are associated with a 2% 5-year overall survival rate. There are limited treatment options for these patients, and no targeted therapy or immunotherapy is available. Rational therapeutic targets remain to be found. In this review, we present the published literature and our own recent experience in molecular biology to identify important molecules and signaling pathways as well as cellular immunity involved in the peritoneal metastasis of GC. We also suggest potential novel strategies for improving the outcomes of GC patients with peritoneal metastasis.

Trop2 inhibition of P16 expression and the cell cycle promotes intracellular calcium release in OSCC

Trop2 is an intracellular calcium signal transducer and a prognostic biomarker in many cancers. P16 is a cell cycle gene that negatively regulates cell proliferation and division in most human cancers. Oral squamous cell carcinoma (OSCC) is a common malignant tumor subgroup of head and neck squamous cell carcinoma worldwide. Both Ca²⁺-dependent and cell cycle signaling pathways play vital roles in OSCC, although the molecular mechanisms remain to be elucidated. We aimed to examine the function of Trop2 and P16 in regulating intracellular calcium ions and the cell cycle in OSCC cell lines. Furtherly, the mRNA and protein expression levels of Trop2 and P16 in OSCC tissue samples were assessed, and their function was evaluated as potential clinical prognostic biomarkers. Trop2 promoted intracellular calcium ion release in OSCC and induced S phase of the cell cycle. Moreover, Trop2-mediated Ca²⁺ inhibited P16 expression through the AMP-activated protein kinase pathway in OSCC. Interestingly, P16 overexpression could not reverse these phenomena in vitro. We also demonstrated that human OSCC tissues showed high Trop2 mRNA and protein expression, and Trop2+/P16- expression is an independent prognostic marker for OSCC patients. Our data suggest that Trop2+/P16- may be a valuable prognostic marker for OSCC and that Trop2 inhibits P16 expression and induces S phase by promoting intracellular calcium release in OSCC.

Trop2 is upregulated in the transition to dysplasia in the metaplastic gastric mucosa

Intestinal-type gastric adenocarcinoma arises in a field of pre-existing metaplasia. While biomarkers of cancer and metaplasia have been identified, the definition of dysplastic transition as a critical point in the evolution of cancer has remained obscure. We have evaluated Trop2 as a putative marker of the transition from metaplasia to dysplasia in the stomach in multiple mouse models of metaplasia induction and progression. In addition, TROP2 expression was evaluated in human samples by immunostaining tissue microarrays for metaplasia, dysplasia, and gastric cancer. Dysplastic mouse organoids were evaluated in vitro following shRNA knockdown of Trop2 expression. In mouse models, no Trop2 was observed in the normal corpus and Trop2 was not induced in acute models of metaplasia induction with either L635 or DMP-777. In Mist1-Kras mice, Trop2 expression was not observed in metaplasia at 1 month after Kras induction, but was observed in dysplastic glands at 3-4 months after Kras induction. In human tissues, no Trop2 was observed in normal corpus mucosa or SPEM, but Trop2 expression was observed in incomplete intestinal metaplasia, with significantly less expression in complete intestinal metaplasia. Trop2 expression was observed in all dysplastic and 84% of gastric cancer lesions, although expression levels were variable. Dysplastic mouse organoids from Mist1-Kras mice expressed Trop2 strongly. Knockdown of Trop2 with shRNA markedly reduced organoid growth and budding behavior, and induced the upregulation of apical villin expression. We conclude that Trop2 is upregulated in the transition to dysplasia in the stomach and promotes dysplastic cell behaviors. © 2020 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Trop2 Promotes Multidrug Resistance by Regulating Notch1 Signaling Pathway in Gastric Cancer Cells

BACKGROUND Chemotherapy is widely used in gastric cancer treatment, but multidrug resistance remains a leading cause of chemotherapy failure. Trop2 is highly expressed in gastric tumor tissues and greatly influences cancer progression. However, little is known about the relationship between Trop2 and drug resistance in gastric cancer. MATERIAL AND METHODS In the present study, Trop2 was knocked down in BGC823 cells and overexpressed in HGC27. CCK-8 assay was performed to explore the relationship of Trop2 expression and cell proliferation treated with anticancer drugs. Flow cytometry was performed to assess the relationship between Trop2 and cell apoptosis after chemotherapy. Subcutaneous xenograft models were generated to explore the curative effect of DDP to GC in vivo. MRP1 and Notch1 expressions were assessed by Western blot. RESULTS Trop2 decreased cell proliferation inhibition and apoptosis after chemotherapeutic treatments. DDP showed stronger therapeutic effects on Trop2-knockdown tumor than control in vivo. MRP1 and Notch1 signaling pathway were confirmed to participate in Trop2-induced drug resistance. CONCLUSIONS Our findings suggest that Trop2 promotes the resistance of gastric cancer to chemotherapy by activating the Notch1 pathway.

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.

Overexpression of PSMA7 predicts poor prognosis in patients with gastric cancer

Gastric cancer (GC) is the fourth most common tumor and the second most common cause of cancer-associated mortality worldwide. Current tumor biomarkers for GC, such as serum carcinoembryonic antigen and carbohydrate antigen 19-9, are not ideal due to their limited role as prognostic indicators for GC. Proteasome subunit α7 (PSMA7) is a multifunctional protein, which has been revealed to be involved in the development and progression of various types of malignancy. However, little is known about the role of PSMA7 in GC. In the present study, PSMA7 was identified to be overexpressed at the mRNA and protein levels in GC tissues, compared with in non-tumor tissues, using reverse transcription-quantitative PCR and immunohistochemistry. Furthermore, PSMA7 expression is associated with tumor invasion, lymph node metastasis, distant metastasis, and Tumor-Node-Metastasis stage. Univariate and multivariate Cox regression analysis identified that PSMA7 expression is an independent prognostic factor for poor survival. Kaplan-Meier survival curves revealed that high PSMA7 expression is associated with a poor prognosis in patients with GC. Overall, the results of the present study suggested that PSMA7 may be a promising biomarker for the prognosis of GC, and may represent a new diagnostic marker and molecular therapeutic target for GC.

Association Between Intra-Tumoral Immune Response and Programmed Death Ligand 1 (PD-L1) in Gastric Cancer

Background

Targeting of PD-1/PD-L1 immune checkpoints exhibits excellent clinical outcomes in numerous types of solid tumors, including gastric cancer. However, the tumor microenvironment of gastric cancer is very complex and the association of PD-L1 with the tumor microenvironment in gastric cancer is still not clear.

Material/Methods

This study analyzed the characteristics of PD-L1 expression and used immunohistochemistry to assess CD8 and CD4 tumor-infiltrating leucocytes (TILs) in 478 cases of gastric cancer compared with the expression patterns in 70 matched adjacent tissues, and 32 cases of benign gastric tissues. Standardized methods for TILs assessment in gastric cancer were used.

Results

The results indicated that PD-L1 expression was increased in gastric cancer tissues (193 out of 478, 40.37%) compared with matched adjacent tissues (14 out of 70, 20.00%) and benign gastric tissues (10 out of 32, 31.25%). It was observed that in gastric cancer patients, positive PD-L1 status in tumor cells (tPD-L1) was associated with distant metastasis (χ²=3.344, P=0.044). The positive expression pattern of tPD-L1 was associated with higher density of TILs, and this pattern was most significant in the non-metastasis group, compared to the metastasis group. We also found that tPD-L1 was not prognostic for overall survival in gastric cancer patients, but tPD-L1 and tCD8 combined positive status in gastric cancer patients was strongly associated with better overall survival rates both in the univariate analysis [hazard ratio (HR)=2.341, 95% confidence interval (CI)=1.147–3.556, P<0.001 and in the multivariate analysis (HR=1.844, 95% CI=1.136–2.592, P=0.031).

Conclusions

These data suggested an interaction between tPD-L1 expression and TILs in gastric cancer, and tPD-L1 expression positively correlated with high densities of tCD8 and indicated a better overall survival and decreased metastasis in gastric cancer patients.

The killing effect of novel bi-specific Trop2/PD-L1 CAR-T cell targeted gastric cancer

Due to their high heterogeneity and complex tumor microenvironment, the treatment of solid tumors by CAR-T cell technology is limited. This study developed bi-specific Trop2/PD-L1 specific third-generation CAR-T cells by lentiviral infection. The specific killing ability of the bi-specific CAR-T cells against Trop2⁺ and PD-L1⁺ expressed on the gastric cancer cell line by CCK-8 assay, was confirmed in vitro. The killing ability of bi-specific Trop2/PD-L1 CAR-T cells was higher than that of mono-specific CAR-T cells (Trop2 CAR-T and PD-L1 CAR-T) and the independent control group (CD19-CAR-T and CIK). The bi-specific Trop2/PD-L1 CAR-T cells produced IFN-γ and IL-2 in response to the overexpression of Trop2 and PD-L1 in gastric cancer cells through ELASA assay. The levels of cytokines (IFN-γ and IL-2) released by bi-specific Trop2/PD-L1 CAR-T cells were the highest among all other types of CAR-T cells and the independent control group. To further demonstrate the ability of bi-specific Trop2/PD-L1 CAR-T cells in vivo, this study testified to the anti-tumor effect of several types of CAR-T cells through a xenograft model bearing human gastric tumors. The results indicated that bi-specific Trop2/PD-L1 CAR-T cells can significantly reduce the tumor growth through intratumoral injection, with a higher inhibition effect than Trop2 specific CAR-T cells and the independent control group (CD19-CAR-T and untreated group). These results suggest that novel bi-specific Trop2/PD-L1 CAR-T cells are able to target Trop2/PD-L1 and checkpoint blockade, and reveal the killing effect on gastric cancer, therefore improving the killing effect of CAR-T cells in solid tumors.

Targeting Trop-2 in solid tumors: future prospects

Trop-2 is a transmembrane glycoprotein that is upregulated in all cancer types independent of baseline levels of Trop-2 expression. Trop-2 is an ideal candidate for targeted therapeutics due to it being a transmembrane protein with an extracellular domain overexpressed on a wide variety of tumors as well as its upregulated expression relative to normal cells. As a result, several Trop-2-targeted therapeutics have recently been developed for clinical use, such as anti-Trop-2 antibodies and Trop-2-targeted antibody-drug conjugates (ADC). Subsequently, multiple early-phase clinical trials have demonstrated safety and clinical benefit of Trop-2-based ADCs across multiple tumor types. This includes clinical benefit and tolerability in tumor types with limited treatment options, such as triple-negative breast cancer, platinum-resistant urothelial cancer, and small-cell lung cancer. In this review, we elaborate on all clinical trials involving Trop-2.

Elevated epiregulin expression predicts poor prognosis in gastric cancer

Epiregulin (EREG) is a novel family member of EGF-like ligands and have elevated expression in a variety of human cancers. EREG expression promotes tumor progression and metastasis and reduces patient survival. However, the expression of EREG and its prognostic value are not clear in gastric cancer (GC). We assessed EREG mRNA and protein expression in GC tissues from Chinese patients using quantitative real-time polymerase chain reaction (qRT-PCR) and immunohistochemical staining of tissue microarray, and analyzed the correlation between the level of EREG expression and patient clinical characteristics and prognosis. We found that EREG expression was significantly higher in GC tissues than in matched adjacent noncancerous tissues. High EREG protein expression in GC was significantly associated with TNM stage including tumor size, lymph node metastases and distant metastases as well as poor overall survival. These finding demonstrate that EREG is an independent prognostic biomarker for GC.

Silencing of the TROP2 gene suppresses proliferation and invasion of hepatocellular carcinoma HepG2 cells

Objectives

Overexpression of human trophoblast cell surface antigen 2 (Trop2) has been observed in many cancers; however, its roles in proliferation, apoptosis, migration, and invasion of hepatocellular carcinoma (HCC) remain unclear. Thus, this study aimed to characterize the function of Trop2 in HCC.

Methods

Trop2 protein expression was detected by immunohistochemistry in HCC tissues. Cell proliferation, apoptosis, and invasion were respectively measured by CCK-8, flow cytometry, Transwell, and wound healing assays. Expression levels of epithelial–mesenchymal transition-related proteins and Trop2 protein in HCC cell lines were detected by western blotting after silencing of the TROP2 gene.

Results

Trop2 protein was highly expressed in HCC tissues and HCC cell lines. Trop2 mRNA and protein expression levels decreased in HepG2 and HCCLM3 cells after transfection with Trop2 siRNA. Silencing of the TROP2 gene in HepG2 and HCCLM3 cells strongly inhibited cell proliferation and migration, while enhancing cell apoptosis. Investigation of the molecular mechanism revealed that silencing of the TROP2 gene suppressed epithelial–mesenchymal transition of HepG2 and HCCLM3 cells.

Conclusions

The results of the present study may improve understanding of the role of Trop2 in regulation of cell proliferation and invasion, and may aid in development of novel therapy for HCC.

The role and molecular mechanism of Trop2 induced epithelial-mesenchymal transition through mediated β-catenin in gastric cancer

The present study elucidates the potential role of Trop2 in tumor invasion and the promotion of epithelial‐mesenchymal transition (EMT) when binding β‐catenin in GC. The role of Trop2 in promoting EMT in GC cells was examined by a variety of experimental assays. Moreover, the underlying molecular mechanism of Trop2 in promoting EMT was studied by in vivo and in vitro assays. The Trop2 expression in relation to tumor metastasis status was detected by IHC in 248 cases of GC tissues and 86 cases of matched adjacent tissues. Trop2 promoted the metastasis and induces EMT in GC. Meanwhile, the elevated protein levels of Trop2 and mesenchymal markers were also found in the TGF‐β1‐induced EMT model in GC cells. Importantly, Trop2 physically bound and activated β‐catenin to promote EMT; moreover, Trop2 increased the accumulation of β‐catenin in the nucleus to accelerate metastasis in GC cells. Inhibition of Trop2 expression in GC cells prevented the migration and invasion of GC cells in vivo. Trop2+/vimentin+ expression was higher in GC tissues than that in matched adjacent tissues, and Trop2+/vimentin+ expression in GC was associated with the differentiation, TNM stage, and distant metastases. These sets of data reveal a novel regulatory network of Trop2 in EMT and GC metastasis, suggesting Trop2 as a useful marker for inducing EMT and metastasis of GC, which may help to lead a better understanding of the pathogenesis of the GC.

TROP2 promotes the proliferation and metastasis of glioblastoma cells by activating the JAK2/STAT3 signaling pathway

Trophoblast cell surface antigen 2 (TROP2), a single transmembrane domain protein, is often found to be highly expressed in various types of human cancers. However, the biological function and molecular mechanism of TROP2 in glioblastoma have not been fully elucidated, particularly in regards to cell proliferation and metastasis of glioblastoma cells. In the present study, it was demonstrated that TROP2 expression was increased in glioblastoma tissues and glioblastoma cell lines by immunohistochemical analysis and western blot analysis. High TROP2 expression was significantly correlated with the poor survival of glioblastoma patients. MTT assay, BrdU incorporation assay, flow cytometry and Transwell assay were performed to demonstrate that knockdown of TROP2 in glioblastoma cells inhibited cell proliferation and metastasis. We found that the effects of TROP2-knockdown on glioblastoma cells were associated with the inhibition of JAK2 and STAT3 phosphorylation and decreased transcription of STAT3 target genes. In addition, blocking the activation of JAK2/STAT3 signaling by WP1066 negated the effects of TROP2 overexpression. Furthermore, exogenous IL-6, which functions as a potent activator of JAK2/STAT3 signaling, was able to rescue the phosphorylation of JAK2 and STAT3 in TROP2-silenced glioblastoma cells and regulate phenotypic changes in these cells. Therefore, we revealed a novel mechanism by which TROP2 activates the JAK2/STAT3 pathway to promote the growth and metastasis of glioblastoma cells. These data offer insight into the function of TROP2 in glioblastoma and indicate that TROP2 is a promising biomarker and therapeutic target for glioblastoma patients.

High expression of TROP2 is correlated with poor prognosis of oral squamous cell carcinoma

Human trophoblastic cell-surface antigen 2 (TROP2) is a cell surface glycoprotein that exhibits high expression in various carcinomas but low or no expression in normal tissues. High TROP2 expression plays an important role in promoting tumor development and aggressiveness, which is correlated with reduced patient survival. However, there are few studies regarding TROP2 in relation to both oral squamous cell carcinoma (OSCC) and oral potentially malignant lesions. The expression of TROP2 protein and mRNA was investigated in OSCC tissues, oral potentially malignant lesion tissues, and normal oral tissues using immunohistochemistry and quantitative real-time polymerase chain reaction (qRT-PCR). The association between TROP2 expression and clinicopathological characteristics of OSCC was also analyzed, and the prognostic value of TROP2 was evaluated. The expression of TROP2 protein and mRNA were both higher in OSCC tissues than in oral potentially malignant lesion tissues or normal oral tissues. Positive TROP2 expression was related to differentiation, lymph node metastases, TNM stage, perineural infiltration, and vascular invasion. Poor overall survival was associated with high TROP2 expression and other factors associated with poor overall survival including poor differentiation, lymph node metastasis, TNM stage, vascular invasion, and perineural invasion in univariate analyses. TROP2 expression as well as TNM stage and vascular invasion were independent prognostic factors associated with the overall survival of OSCC patients in multivariate analyses. In summary, High TROP2 expression is associated with poor overall survival and serves as an independent prognostic factor in OSCC. The results suggest that TROP2 expression could be an effective prognostic biomarker for OSCC.

Review of recent efforts to discover biomarkers for early detection, monitoring, prognosis, and prediction of treatment responses of patients with gastric cancer

Gastric cancer (GC) is the leading cause of cancer-related death worldwide. Despite recent advances in diagnosis and therapy, the prognosis of patients with GC is poor. Many patients have inoperable disease upon diagnosis or experience recurrent disease after curative gastrectomy. Unfortunately, tumor markers for GC, such as serum carcinoembryonic antigen and carbohydrate antigen 19-9, lack sufficient sensitivity and specificity. Therefore, effective biomarkers are required to detect early GC and to predict tumor recurrence and chemosensitivity. Areas covered: Here we aimed to review recent developments in techniques that improve the detection of aberrant expression of GC-associated molecules, including protein coding genes, microRNAs, long noncoding RNAs, and methylated promoter DNAs. Expert commentary: Detection of genetic and epigenetic alterations in gastric tissue or in the circulation will likely improve the diagnosis and management of GC to achieve significantly improved outcomes.

The diagnostic value of TROP-2, SLP-2 and CD56 expression in papillary thyroid carcinoma

OBJECTIVE

The study aimed to explore some novel diagnostic biomarkers for papillary thyroid carcinoma (PTC) by identifying the different expression of TROP-2, SLP-2 and CD56 in benign and malignant thyroid lesions.

METHODS

We evaluated the mRNA expressions of TROP-2 and SLP-2 in fine needle aspirates (FNAs) which contained 10 PTCs and 10 benign follicular adenomas (FAs) using quantitative real-time PCR (qRT-PCR). Immunohistochemical (IHC) staining of TROP-2, SLP-2 and CD56 was also performed on postoperative samples of 30 PTCs and 29 FAs. Membranous or cytoplasmic staining in > 10% of cells was considered as positive. Diagnostic sensitivity, specificity, positive predictive value, negative predictive value (NPV) and diagnostic accuracy of these three biomarkers were carried out. We further analyzed the associations between the clinical features and the expressions of markers in PTCs.

RESULTS

The mRNA expressions of both TROP-2 and SLP-2 were increased substantially in PTCs in comparison with those in FAs (P < 0.05). Similarly, IHC for these two proteins demonstrated higher positive staining in PTCs than in FAs (96.5% vs. 12.5% for TROP-2, 83.3% vs. 20.7% for SLP-2, P < 0.05). Conversely, CD56 expression was lost with 86.7% of PTCs. In identifying malignancy, TROP-2 was the most sensitive marker and CD56 was the most specific one. When the markers were combined, the sensitivity and NPV increased to 100% and had better diagnostic accuracy. However, no association was found between biomarker expressions and clinicopathological factors in PTCs.

CONCLUSIONS

We found that TROP-2, SLP-2 and CD56 were effective diagnostic markers for PTC, especially when they were combined to use.

TROP2 promotes cell proliferation and migration in osteosarcoma through PI3K/AKT signaling

Human trophoblast cell surface antigen 2 (TROP2) has been noted to serve an important role in the proliferation and migration of various types of human cancers. However, the potential role and the molecular mechanisms of TROP2 in osteosarcoma (OS) remain largely unclear. In the present study, high expression of TROP2 in human OS tissues and cell lines was observed. Overexpression of TROP2 promoted the proliferation and migration of OS cell lines, while TROP2 knockdown markedly decreased cell growth and migration. Furthermore, it was revealed that TROP2 overexpression significantly activated the phosphoinositide 3‑kinase/protein kinase B (PI3K/AKT) signaling pathway. Collectively, these results suggested that TROP2 may promote OS cell proliferation and migration via PI3K/AKT signaling and may serve as a novel treatment target for OS.

TROP2 promotes proliferation, migration and metastasis of gallbladder cancer cells by regulating PI3K/AKT pathway and inducing EMT

The human trophoblast cell surface antigen 2 (TROP2) is overexpressed in many cancers. However, its effect on proliferation, migration and metastasis of gallbladder cancer remains unclear. In this study, we found that TROP2 was highly expressed in gallbladder cancer. Overexpression of TROP2 was associated with poor prognosis. Knockdown of TROP2 in gallbladder cancer cell lines strongly inhibited the cell proliferation, clone formation, invasion and migration in vitro, while TROP2 overexpression had opposite effects. In addition, knockdown of TROP2 increased the expression of total PTEN, p-PTEN and PDK-1 but reduced p-AKT via PI3K/AKT pathway. TROP2 downregulation also inhibited vimentin and increased E-cadherin expression during epithelial-mesenchymal transition (EMT). Moreover, gallbladder cancer cells with TROP2 knockdown formed smaller xenografted tumors in vivo. In consistent with in vitro results, TROP2 inhibition decreased Akt phosphorylation, increased PTEN expression and postponed EMT of gallbladder cancer cells in vivo. In conclusion, we revealed that TROP2 promoted the proliferation, migration and metastasis of gallbladder cancer cells by regulating PI3K/AKT pathway and inducing EMT. TROP2 could serve as a potential prognostic biomarker and therapeutic target for the clinical management of gallbladder cancer.

Association of tumor TROP2 expression with prognosis varies among lung cancer subtypes

TROP2 is a transmembrane glycoprotein that is overexpressed in various cancers. Emerging evidence suggests that TROP2-targeting therapies are efficacious and safe in patients with multiple prior treatments. TROP2 is a promising target for lung cancer treatment; however, little is known regarding the association of TROP2 expression with clinicopathological/molecular features, including prognosis, in lung cancer. We examined consecutive cases of adenocarcinoma, squamous cell carcinoma (SqCC), and high-grade neuroendocrine tumor (HGNET) for the membranous expression of TROP2 using immunohistochemistry. High TROP2 expression was observed in 64% (172/270) of adenocarcinomas, 75% (150/201) of SqCCs, and 18% (21/115) of HGNETs. Intriguingly, the association of TROP2 expression with mortality was dependent on the lung cancer subtype. High TROP2 expression was associated with higher lung cancer-specific mortality in adenocarcinomas [univariable hazard ratio (HR) = 1.60, 95% confidence interval (CI) = 1.07–2.44, P = 0.022)], but not in SqCCs (univariable HR = 0.79, 95% CI = 0.35–1.94, P = 0.79). In HGNETs, high TROP2 expression was associated with lower lung cancer-specific mortality in both univariable and multivariable analyses (multivariable HR = 0.13, 95% CI = 0.020–0.44, P = 0.0003). Our results suggest a differential role for TROP2 in different lung cancer subtypes.

A phase 1, dose-escalation study of PF-06664178, an anti-Trop-2/Aur0101 antibody-drug conjugate in patients with advanced or metastatic solid tumors

Purpose and Methods Trop-2 is a glycoprotein over-expressed in many solid tumors but at low levels in normal human tissue, providing a potential therapeutic target. We conducted a phase 1 dose-finding study of PF-06664178, an antibody-drug conjugate that targets Trop-2 for the selective delivery of the cytotoxic payload Aur0101. The primary objective was to determine the maximum tolerated dose and recommended phase 2 dose. Secondary objectives included further characterization of the safety profile, pharmacokinetics and antitumor activity. Eligible patients were enrolled and received multiple escalating doses of PF-06664178 in an open-label and unblinded manner based on a modified continual reassessment method. Results Thirty-one patients with advanced or metastatic solid tumors were treated with escalating doses of PF-06664178 given intravenously every 21 days. Doses explored ranged from 0.15 mg/kg to 4.8 mg/kg. Seven patients experienced at least one dose limiting toxicity (DLT), either neutropenia or rash. Doses of 3.60 mg/kg, 4.2 mg/kg and 4.8 mg/kg were considered intolerable due to DLTs in skin rash, mucosa and neutropenia. Best overall response was stable disease in 11 patients (37.9%). None of the patients had a partial or complete response. Systemic exposure of PF-06664178 increased in a dose-related manner. Serum concentrations of free Aur0101 were substantially lower than those of PF-06664178 and total antibody. No correlation of Trop-2 expression and objective response was observed, although Trop-2 overexpression was not required for study entry. The intermediate dose of 2.4 mg/kg appeared to be the highest tolerated dose, but this was not fully explored as the study was terminated early due to excess toxicity. Conclusion PF-06664178 showed toxicity at high dose levels with modest antitumor activity. Neutropenia, skin rash and mucosal inflammation were dose limiting toxicities. Findings from this study may potentially aid in future antibody drug conjugate design and trials.

Prognostic role and clinical significance of trophoblast cell surface antigen 2 in various carcinomas

Introduction

Trophoblast cell surface antigen 2 (TROP2) has been linked to disease prognosis in various human cancers and plays a critical role in tumor development, progression, and metastasis. A number of relevant studies have been published on this topic. A meta-analysis of the latest literature to evaluate the value of TROP2 as a predictive prognosticator of cancer was performed.

Methods

Several online databases were searched, and relevant articles were retrieved. Overall and subcategory meta-analyses were performed, and results were collated.

Results

Twenty-seven articles, including 29 studies, were included, involving 4,852 cancer patients, and results showed that the above-baseline expression of TROP2 was significantly associated with poorer overall survival (OS) (pooled hazard ratio [HR]: 1.84, 95% confidence interval [CI]: 1.45–2.35), disease-free survival (DFS) (pooled HR: 2.77, 95% CI: 1.73–4.42), and progression-free survival (PFS) (pooled HR: 1.71, 95% CI: 1.25–2.35). The following clinical characteristics were also significantly linked with TROP2 overexpression: moderate/poor differentiation (pooled HR: 3.03, 95% CI: 1.99–4.63), distant metastasis (pooled HR: 2.46, 95% CI: 1.05–5.75), lymph node metastasis (pooled HR: 2.47, 95%: CI 1.72–3.56), and advanced TNM stage (pooled HR: 2.02, 95% CI: 1.38–2.95).

Conclusion

TROP2 overexpression was predictive of poor prognosis in human cancers and may be an independent prognostic predictive biomarker. Further studies should be performed to confirm the significance of TROP2 in clinical practice.

Positive Helicobacter pylori status is associated with better overall survival for gastric cancer patients: evidence from case-cohort studies

Helicobacter pylori (H. pylori) infection increases the gastric cancer risk; however, the influences of H. pylori infection status on the outcomes for gastric cancer patients have not yet clearly defined. Herein, we systematically assessed the epidemiological studies regarding the associations between the H.pylori infection status at diagnosis and the prognosis for gastric cancer patients with the meta-analysis methods. Thirty-three eligibility studies with 8,199 participants that had determined the H.pylori infection status and the outcomes for gastric cancer patients were identified through searching the PubMed and MEDLINE databases updated to March 1^st, 2017. The random-effects model suggested that positive H. pylori infection was associated with better overall survival with the pooled hazard ratio (HR) was 0.79 [95% confidence interval (CI) = 0.66-0.93; Q = 134.86, df = 32, P-heterogeneity < 0.001; I² = 76.3%] compared to negative patients. The association was found to be more prominent in studies with higher quality, longer following-up time and more sensitive detection methods. An inverse but not statistically significant association between the H.pylori status and the disease-free survival of the patients (pooled HR = 0.84, 95% CI = 0.61-1.05;Q = 30.48, df = 11, P-heterogeneity = 0.001; I² = 63.9%) was found, while no significant association was noticed in any subgroup analyses. These results suggested that gastric cancer patients with positive H.pylori infection status at diagnosis have better overall survival compared to negative; however, more studies are warranted to confirm the results and elucidate the underlying mechanisms.