Reduced E-Cadherin and Aberrant β-Catenin Expression are Associated With Advanced Disease in Signet-Ring Cell Carcinomas

A prognostic framework for predicting lung signet ring cell carcinoma via a machine learning based cox proportional hazard model

PURPOSE

Signet ring cell carcinoma (SRCC) is a rare type of lung cancer. The conventional survival nomogram used to predict lung cancer performs poorly for SRCC. Therefore, a novel nomogram specifically for studying SRCC is highly required.

METHODS

Baseline characteristics of lung signet ring cell carcinoma were obtained from the Surveillance, Epidemiology, and End Results (SEER) database. Univariate and multivariate Cox regression and random forest analysis were performed on the training group data, respectively. Subsequently, we compared results from these two types of analyses. A nomogram model was developed to predict 1-year, 3-year, and 5-year overall survival (OS) for patients, and receiver operating characteristic (ROC) curves and calibration curves were used to assess the prediction accuracy. Decision curve analysis (DCA) was used to assess the clinical applicability of the proposed model. For treatment modalities, Kaplan-Meier curves were adopted to analyze condition-specific effects.

RESULTS

We obtained 731 patients diagnosed with lung signet ring cell carcinoma (LSRCC) in the SEER database and randomized the patients into a training group (551) and a validation group (220) with a ratio of 7:3. Eight factors including age, primary site, T, N, and M.Stage, surgery, chemotherapy, and radiation were included in the nomogram analysis. Results suggested that treatment methods (like surgery, chemotherapy, and radiation) and T-Stage factors had significant prognostic effects. The results of ROC curves, calibration curves, and DCA in the training and validation groups demonstrated that the nomogram we constructed could precisely predict survival and prognosis in LSRCC patients. Through deep verification, we found the constructed model had a high C-index, indicating that the model had a strong predictive power. Further, we found that all surgical interventions had good effects on OS and cancer-specific survival (CSS). The survival curves showed a relatively favorable prognosis for T0 patients overall, regardless of the treatment modality.

CONCLUSIONS

Our nomogram is demonstrated to be clinically beneficial for the prognosis of LSRCC patients. The surgical intervention was successful regardless of the tumor stage, and the Cox proportional hazard (CPH) model had better performance than the machine learning model in terms of effectiveness.

Gastrointestinal signet ring cell malignancy: current advancement and future prospects

Globally, gastrointestinal cancer is the most widespread neoplastic disease and the primary contributor to cancer-associated fatalities. Gastrointestinal signet ring cell carcinoma (SRCC) exhibits unique distinguishing features in several aspects when compared to adenocarcinomas (ACs). The scarcity of signet ring cell carcinoma has resulted in a heightened significance of related clinical and molecular investigations. However, a comprehensive and systematic review of the clinical, molecular, therapeutic, and research aspects of this disease is currently absent. This review provides an overview of the latest developments in our understanding of the clinical and molecular features of gastrointestinal signet ring cell carcinoma (SRCC). Additionally, we have compiled a list of potential therapeutic targets or biomarkers, as well as an examination of the current treatment options and the possible mechanisms of formation.

Potential therapeutic targets discovery by transcriptome analysis of an in vitro human gastric signet ring carcinoma model

BACKGROUND

Loss of E-cadherin expression is frequently observed in signet ring carcinoma (SRCC). People with germline mutations in CDH1, which encodes E-cadherin, develop diffuse gastric cancer at a higher rate. Loss of E-cadherin expression is thus assumed to trigger oncogenic development.

METHODS

To investigate novel therapeutic targets for gastric SRCC, we engineered an E-cadherin-deficient SRCC model in vitro using a human gastric organoid (hGO) with CDH1 knockout (KO).

RESULTS

CDH1 KO hGO cells demonstrated distinctive morphological changes similar to SRCC and high cell motility. RNA-sequencing revealed up-regulation of matrix metalloproteinase (MMP) genes in CDH1 KO hGO cells compared to wild type. MMP inhibitors suppressed cell motility of CDH1 KO hGO cells and SRCC cell lines in vitro. Immunofluorescent analysis with 95 clinical gastric cancer tissues revealed that MMP-3 was specifically abundant in E-cadherin-aberrant SRCC. In addition, CXCR4 molecules translocated onto the cell membrane after CDH1 KO. Addition of CXCL12, a ligand of CXCR4, to the culture medium prolonged cell survival of CDH1 KO hGO cells and was abolished by the inhibitor, AMD3100. In clinical SRCC samples, CXCL12-secreting fibroblasts showed marked infiltration into the cancer area.

CONCLUSIONS

E-cadherin deficient SRCCs might gain cell motility through upregulation of MMPs. CXCL12-positive cancer-associated fibroblasts could serve to maintain cancer-cell survival as a niche. MMPs and the CXCL12/CXCR4 axis represent promising candidates as novel therapeutic targets for E-cadherin-deficient SRCC.

Signet ring cell cancer of stomach and gastro-esophageal junction: molecular alterations, stage-stratified treatment approaches, and future challenges

Purpose

There has been an increase in the incidence of signet ring cell cancer (SRCC) of the stomach and gastro-esophageal junction (GEJ). The multistage carcinogenesis involving genetic and epigenetic aberrations may have a major role in the increasing incidence of SRCC. Although there are numerous studies on the prognostic value of SRCC, they are markedly inconsistent in their results, making it impossible to draw any meaningful conclusions. We aimed to examine the available evidences on molecular alterations and stage-stratified treatment approaches in SRCC of the stomach and GEJ.

Methods

A systematic search was carried out in PubMed. Studies available in English related to SRCC of stomach and gastro-esophageal junction were identified and evaluated.

Results

This study reviewed the current evidence and provided an insight into the molecular alterations, stage-stratified treatment approaches, and future challenges in the management of SRCC of the stomach and GEJ. Specific therapeutic strategies and personalized multimodal treatment have been recommended based on the tumor characteristics of SRCC.

Conclusion

Multistage carcinogenesis involving genetic and epigenetic aberrations in SRCC is interlinked with stage-dependent prognosis. Specific therapeutic strategy and personalized multimodal treatment should be followed based on the tumor characteristics of SRCC. Endoscopic resection, radical surgery, and perioperative chemotherapy should be offered in carefully selected patients based on stage and prognostic stratification. Future studies in genetic and molecular analysis, histopathological classification, and options of multimodality treatment will improve the prognosis and oncological outcomes in SRCC of gastric and GEJ.

Overview on new progress of hereditary diffuse gastric cancer with CDH1 variants

Hereditary diffuse gastric cancer (HDGC), comprising 1%-3% of gastric malignances, has been associated with CDH1 variants. Accumulating evidence has demonstrated more than 100 germline CDH1 variant types. E-cadherin encoded by the CDH1 gene serves as a tumor suppressor protein. CDH1 promoter hypermethylation and other molecular mechanisms resulting in E-cadherin dysfunction are involved in the tumorigenesis of HDGC. Histopathology exhibits characteristic signet ring cells, and immunohistochemical staining may show negativity for E-cadherin and other signaling proteins. Early HDGC is difficult to detect by endoscopy due to the development of lesions beneath the mucosa. Prophylactic gastrectomy is the most recommended treatment for pathogenic CDH1 variant carriers. Recent studies have promoted the progression of promising molecular-targeted therapies and management strategies. This review summarizes recent advances in CDH1 variant types, tumorigenesis mechanisms, diagnosis, and therapy, as well as clinical implications for future gene therapies.

Differentiating breast carcinoma with signet ring features from gastrointestinal signet ring carcinoma: assessment of immunohistochemical markers

Signet ring morphology is recognized throughout the gastrointestinal tract. However, this pattern may be observed in other primary sites giving rise to diagnostic challenges in the work-up of metastases. Relatively newer immunohistochemical markers have not been evaluated in this context. We assessed expression patterns of several common immunohistochemical markers in tumors with Signet ring morphology to delineate a pragmatic approach to this differential diagnosis. Primary breast and gastrointestinal carcinomas showing Signet ring features were reviewed. Non-mammary and non-gastrointestinal tumors with this morphology were included for comparison. Estrogen receptor (ER), progesterone receptor (PR), E-cadherin, CK7, CK20, GCDFP-15, mammaglobin, CDX2, GATA-3, and HepPar-1 immunohistochemistry was performed. Expression patterns were compared between breast and gastrointestinal tumors as well as lobular breast and gastric tumors. Ninety-three cases were identified: 33 breast carcinomas including 13 lobular, 50 gastrointestinal tumors including 23 gastric, and 10 from other sites. ER (sensitivity=81.8%, specificity=100%, positive predictive value (PPV)=100%, negative predictive value (NPV)=89.3%) and GATA-3 (sensitivity=100%, specificity=98%, PPV=96.8%, NPV=100%) expression were associated with breast origin. CK20 (sensitivity=66.7%, specificity=93.3%, PPV=94.1%, NPV=63.6%) and CDX2 (sensitivity=72%, specificity=100%, PPV=100%, NPV=68.9%) demonstrated the strongest discriminatory value for gastrointestinal origin. These markers exhibited similar discriminatory characteristics when comparing lobular and gastric signet ring carcinomas. In a limited trial on metastatic breast and gastric cases, these markers successfully discriminated between breast and gastric primary sites in 15 of 16 cases. ER and GATA-3 are most supportive of mammary origin and constitute an effective panel for distinguishing primary breast from primary gastrointestinal Signet ring tumors when combined with CK20 and CDX2 immunohistochemistry.