Cd44v6 acts as a directional responding factor in the process of transcoelomic metastasis from gastric carcinoma to Krukenberg tumor.

INTRODUCTION: Due to the limited number of studies focusing on the optimal treatment of multiple Krukenberg tumor (KT)-gastric carcinoma (KT - GC), it is necessary to conduct large-scale studies to confirm the definite role of serum tumor markers in the diagnosis and prognosis of KT. Moreover, the clinical significance of variant 6 of CD44 (CD44v6) in transcoelomic metastasis should be considered. AREAS COVERED: This review covers molecular pre-cancer diagnosis, gastric carcinoma metastasis, and anti-cancer treatments. Additionally, gastrointestinal cancer metastasis is a key area for improvement. EXPERT OPINION: The detection of CD44v6 differs in the World Health Organization Classification of Gastric Adenocarcinoma, the Lauren Classification of Gastric Adenocarcinoma, and the anatomic location of gastric adenocarcinoma. The results were compared among the three groups. The mechanism of gastric adenocarcinoma metastasis still requires further elucidation. CD44v6 molecular detection helps clarify the pre-cancer diagnosis of KT before seeding. If subsequent studies confirm its role as a signaling molecule, it could pave the way for new research directions in clinical practice; however, additional academic confirmation is necessary.

A comparative study of RTK gene status between primary tumors, lymph-node metastases, and Krukenberg tumors.

Krukenberg tumor (KT) refers to a rare ovarian tumor that has metastasized from a primary site. Patients with KTs have a poorer prognosis and worse survival. Thus far, little is known about the frequency of receptor tyrosine kinase (RTK) gene amplification and the concordance of gene amplification between primary tumors, lymph-node metastases, and KTs. Herein, 50 paired samples, including primary cancers, metastatic lymph nodes, and KTs were collected, and RTK gene amplification was tested by fluorescence in situ hybridization (FISH). There were four cases positive for human epidermal growth factor receptor type 2 (HER2) amplification, all of which showed conversion of HER2 status between different lesions. Of the two cases with c-mesenchymal-epithelial transition (c-MET) amplification, the primary tumors and lymph nodes were negative while the right involved ovaries were positive. Inconsistent fibroblast growth factor receptor 2 (FGFR2) status in different lesions was observed in three of the six FGFR2-amplified cases. Co-amplification of RTK genes was identified in only one patient for primary cancer and two for KTs. Collectively, there were 46, 48, 50, and 44 cases negative for HER2, c-MET, EGFR, and FGFR2 amplification in all lesions, respectively. There was no significant difference in overall survival between KTs of gastric origin and colorectal origin. However, of all synchronous cancers, KTs of colorectal origin had a better prognosis than those of gastric origin. In conclusion, the positive rate of RTK gene amplification in KTs was low. Intratumoral heterogeneity was frequent in KTs with RTK gene amplification. A mutually exclusive pattern of RTK gene amplification was dominant in primary cancers, lymph-node metastases, and KTs. There was no survival difference between KTs of gastric origin and colorectal origin. However, of all synchronous cancers, KTs of colorectal origin had a better prognosis than those of gastric origin.

An Optimised Protocol Harnessing Laser Capture Microdissection for Transcriptomic Analysis on Matched Primary and Metastatic Colorectal Tumours.

Generation of large amounts of genomic data is now feasible and cost-effective with improvements in next generation sequencing (NGS) technology. Ribonucleic acid sequencing (RNA-Seq) is becoming the preferred method for comprehensively characterising global transcriptome activity. Unique to cytoreductive surgery (CRS), multiple spatially discrete tumour specimens could be systematically harvested for genomic analysis. To facilitate such downstream analyses, laser capture microdissection (LCM) could be utilized to obtain pure cell populations. The aim of this protocol study was to develop a methodology to obtain high-quality expression data from matched primary tumours and metastases by utilizing LCM to isolate pure cellular populations. We demonstrate an optimized LCM protocol which reproducibly delivered intact RNA used for RNA sequencing and quantitative polymerase chain reaction (qPCR). After pathologic annotation of normal epithelial, tumour and stromal components, LCM coupled with cDNA library generation provided for successful RNA sequencing. To illustrate our framework's potential to identify targets that would otherwise be missed with conventional bulk tumour sequencing, we performed qPCR and immunohistochemical technical validation to show that the genes identified were truly expressed only in certain sub-components. This study suggests that the combination of matched tissue specimens with tissue microdissection and NGS provides a viable platform to unmask hidden biomarkers and provides insight into tumour biology at a higher resolution.

Comparison of a Panel of Biomarkers Between Gastric Primary Cancer and the Paired Krukenberg Tumor.

To compare a panel of selected biomarkers between gastric primary cancer and the paired Krukenberg tumor, a total of 21 cases of metastatic tumors originating from stomach and the paired gastric primary cancers were collected. The expressions of a panel of selected biomarkers were tested by IHC. FISH was used to determine the status of HER2/neu in cases scored IHC 2+. The differences of the expressions of the biomarkers were evaluated between metastatic tumors and the paired gastric primary cancers. Bcl-2 was negative in all the cases. The HER2/neu expression was consistent between the gastric primary cancers and the paired metastatic tumors in 17 patients. In the other 4 cases, the HER2/neu expression was negative in gastric primary cancers but positive in the matched metastatic tumors. The concordance rate of c-MET, p53, and Ki-67 expression was 71.4%, 81.0%, and 76.2%, respectively. In conclusion, the expression of Bcl-2 is negative in all gastric primary tumors and the paired metastatic cancers. There is major concordance of the expression of HER2/neu, c-MET, p53, and Ki-67 between gastric primary cancers and the paired metastatic tumors, which suggests that the status of these biomarkers remain stable during the metastatic process.

Metastatic tumor evolution and organoid modeling implicate TGFBR2 as a cancer driver in diffuse gastric cancer.

BACKGROUND: Gastric cancer is the second-leading cause of global cancer deaths, with metastatic disease representing the primary cause of mortality. To identify candidate drivers involved in oncogenesis and tumor evolution, we conduct an extensive genome sequencing analysis of metastatic progression in a diffuse gastric cancer. This involves a comparison between a primary tumor from a hereditary diffuse gastric cancer syndrome proband and its recurrence as an ovarian metastasis. RESULTS: Both the primary tumor and ovarian metastasis have common biallelic loss-of-function of both the CDH1 and TP53 tumor suppressors, indicating a common genetic origin. While the primary tumor exhibits amplification of the Fibroblast growth factor receptor 2 (FGFR2) gene, the metastasis notably lacks FGFR2 amplification but rather possesses unique biallelic alterations of Transforming growth factor-beta receptor 2 (TGFBR2), indicating the divergent in vivo evolution of a TGFBR2-mutant metastatic clonal population in this patient. As TGFBR2 mutations have not previously been functionally validated in gastric cancer, we modeled the metastatic potential of TGFBR2 loss in a murine three-dimensional primary gastric organoid culture. The Tgfbr2 shRNA knockdown within Cdh1-/-; Tp53-/- organoids generates invasion in vitro and robust metastatic tumorigenicity in vivo, confirming Tgfbr2 metastasis suppressor activity. CONCLUSIONS: We document the metastatic differentiation and genetic heterogeneity of diffuse gastric cancer and reveal the potential metastatic role of TGFBR2 loss-of-function. In support of this study, we apply a murine primary organoid culture method capable of recapitulating in vivo metastatic gastric cancer. Overall, we describe an integrated approach to identify and functionally validate putative cancer drivers involved in metastasis.