Invasion and metastasis of SY86B human gastric carcinoma cells in nude mice

Machine learning to predict distant metastasis and prognostic analysis of moderately differentiated gastric adenocarcinoma patients: a novel focus on lymph node indicators

Background

Moderately differentiated gastric adenocarcinoma (MDGA) has a high risk of metastasis and individual variation, which strongly affects patient prognosis. Using large-scale datasets and machine learning algorithms for prediction can improve individualized treatment. The specific efficacy of several lymph node indicators in predicting distant metastasis (DM) and patient prognosis in MDGA remains obscure.

Methods

We collected data from MDGA patients from the SEER database from 2010 to 2019. Additionally, we collected data from MDGA patients in China. We used nine machine learning algorithms to predict DM. Subsequently, we used Cox regression analysis to determine the risk factors affecting overall survival (OS) and cancer-specific survival (CSS) in DM patients and constructed nomograms. Furthermore, we used logistic regression and Cox regression analyses to assess the specific impact of six lymph node indicators on DM incidence and patient prognosis.

Results

We collected data from 5,377 MDGA patients from the SEER database and 109 MDGC patients from hospitals. T stage, N stage, tumor size, primary site, number of positive lymph nodes, and chemotherapy were identified as independent risk factors for DM. The random forest prediction model had the best overall predictive performance (AUC = 0.919). T stage, primary site, chemotherapy, and the number of regional lymph nodes were identified as prognostic factors for OS. Moreover, T stage, number of regional lymph nodes, primary site, and chemotherapy were also influential factors for CSS. The nomograms showed good predictive value and stability in predicting the 1-, 3-, and 5-year OS and CSS in DM patients. Additionally, the log odds of a metastatic lymph node and the number of negative lymph nodes may be risk factors for DM, while the regional lymph node ratio and the number of regional lymph nodes are prognostic factors for OS.

Conclusion

The random forest prediction model accurately identified high-risk populations, and we established OS and CSS survival prediction models for MDGA patients with DM. Our hospital samples demonstrated different characteristics of lymph node indicators in terms of distant metastasis and prognosis.

Frequently Expressed Glypican-3 As A Promising Novel Therapeutic Target for Osteosarcomas

Osteosarcoma (OS) is the most common bone malignancy without a reliable therapeutic target. Glypican-3 (GPC3) mutation and upregulation have been detected in multi-drug resistant OS, and anti-GPC3 immunotherapy can effectively suppress the growth of organoids. Further profiling of GPC3 mutations and expression patterns in OS is of clinical significance. To address these issues, fresh OS specimens were collected from 24 patients for cancer-targeted next-generation sequencing (NGS) and three-dimensional patient-derived organoid (PDO) culture. A tumor microarray was prepared using 37 archived OS specimens. Immunohistochemical (IHC) staining was performed on OS specimens and microarrays to profile GPC3 and CD133 expression as well as intratumoral distribution patterns. RT-PCR was conducted to semi-quantify GPC3 and CD133 expression levels in the OS tissues. Anti-GPC3 immunotherapy was performed on OS organoids with or without GPC3 expression and its efficacy was analyzed using multiple experimental approaches. No OS cases with GPC3 mutations were found, except for the positive control (OS-08). IHC staining revealed GPC3 expression in 73.77% (45/61) of OSs in weak (+; 29/45), moderate (++; 8/45), and strong (+++; 8/45) immunolabeling densities. The intratumoral distribution of GPC3-positive cells was variable in the focal (+; 10-30%; 8/45), partial (++; 31-70%; 22/45), and the most positive patterns (+++; > 71%; 15/45), which coincided with CD133 immunolabeling (P = 9.89×10^-10 ). The anti-GPC3 antibody efficiently inhibits Wnt/β-catenin signaling and induces apoptosis in GPC3-positive PDOs and PDXs, as opposed to GPC3-negative PDOs and PDXs. The high frequency of GPC3 and CD133 co-expression and the effectiveness of anti-wildtype GPC3-ab therapy in GPC3-positive OS models suggest that GPC3 is a novel prognostic parameter and a promising therapeutic target for osteosarcoma.

Establishment and characterization of three novel human gastric cancer cell lines with differentiated intestinal phenotype derived from liver metastasis

Gastric cancers with liver metastasis are fatal diseases with rapid progression and poor patient outcome. To date, however, the molecular basis of their growth and metastasis remains essentially unknown, largely because of the presence of few available gastric cancer cell lines established from liver metastasis. In the present study, we developed two novel cultured cell lines (designated GLM-1 and GLM-2) and one transplantable line in nude mice (designated GLM-3) derived from liver metastasis of gastric cancer patients. These GLM cell lines share unique biological features such as differentiation, growth and metastasis. They form moderately differentiated tumors with CD10 positive and MUC2 negative intestinal absorptive phenotype when injected into nude mice. Their growth is stimulated by EGF and TGF-alpha in vitro like other gastric cancer cell lines. However, GLM cells differ from conventional gastric cancer cell lines in their high apoptotic rate, even in the absence of apoptosis inducing stimuli as revealed by Caspase3/7 assay and the TUNEL method. This apoptosis is further enhanced by phosphatidylinositol 3-kinase (PI3K) inhibitor (LY294002), but not by MEK1/2 inhibitor (U0126), indicating the strong dependency of their survival on PI3K/Akt pathway rather than MAPK pathway, the major downstream signaling pathways of EGFR. GLM-1 cells can metastasize to the liver after intrasplenic injection, and GLM-3 cells have spontaneous lung metastatic potential after subcutaneous transplantation, respectively. These results indicate that the GLM series are the first cell lines reflecting the intestinal-type differentiated adenocarcinoma, a major subtype of gastric cancer with liver metastasis. Therefore, they would be excellent models for understanding the mechanism of metastatic growth and the development of a new molecular targeting therapy for gastric cancer with liver metastasis.

Establishment of two cell lines from human gastric scirrhous carcinoma that possess the potential to metastasize spontaneously in nude mice

Few experimental studies have been conducted to clarify the mechanism of development of metastasis in scirrhous carcinoma of the stomach. In the present study, we attempted to establish gastric carcinoma cell lines by incubation of cancer cells collected from the body fluids of patients with gastric cancer. At the same time, xenografting of these cells to nude mice was performed. It was found that, of the gastric carcinoma cell lines thus established, two cell lines, designated as HSC-44PE and HSC-58, formed s.c. tumors with a high infiltrative potential (often invading the lymphatics around the cancer tissue) when implanted. Metastasis to the lymph nodes and lungs was observed in 20-40% of all the animals, indicating that the two cell lines are also capable of metastasizing spontaneously. Through repeated selection, i.e., repeated cycles of removal, culture, and implantation of the HSC cancer cells from metastatic lesions, we obtained 5 subclones of HSC-44PE and HSC-58 (designated as m2509, m2615, m2792, m2917, and m2691), which, when implanted orthotopically, exhibited the following characteristics as compared to the parent cells: (1) a higher percentage take (survival), similar frequency of metastasis, shorter time to metastasis (less than 100 days), and consistent metastasizing potential; (2) a relatively high frequency of metastasis to lymph nodes, including distant metastasis to axillary lymph nodes; (3) the potential to cause occasional bloody ascites; (4) enhanced expression of dysadherin, CD44, and other molecules. This is the first report of cultured scirrhous gastric carcinoma cells showing the potential for spontaneous metastasis.

Establishment and characterization of a new spontaneous metastasis model of human gastric carcinoma in nude mice

A poorly differentiated medullary carcinoma of human stomach, designated HY-1, was successfully transplanted to nude mice by either the subcutaneous or intramuscular route for five generations. The transplanted tumor showed spontaneous lung metastases in nearly 100% of KSN and Balb/c female nude mice. There were over 20 visible lung metastatic nodules in KSN and Balb/c nude mice bearing tumors for over 80 days. Immunostaining of type IV collagen and electron microscopy revealed that tumor cells were often in direct contact with basement membrane (BM) of tumor blood vessels in the primary tumor tissue. At the site of contact between tumor cells and vascular BM, focal disappearance of the BM, disruption of endothelial cells and entry of tumor cell clusters into vascular lumen were observed. Immunostaining of 72 kDa gelatinase/type IV collagenase demonstrated that tumor cells expressed this enzyme in their cytoplasm. These results suggest that spontaneous metastasis of this tumor may be partly due to a marked tendency to vascular invasion involving the following sequential events: tumor cell contact with vascular BM, BM degradation possibly by 72 kDa gelatinases and endothelial disruption. This model could be a useful tool for understanding the mechanism of hematogenous metastasis of human gastric cancer.