Lymphatic Metastasis Of Gastric Cancer Research Articles

Ultrasensitive in vivo detection of primary gastric tumor and lymphatic metastasis using upconversion nanoparticles.

Lymphatic metastasis is an important prognostic factor regarding long-term survival rate of gastric cancer (GC) patients. Pretreatment knowledge of lymph node status is extremely helpful for planning treatment and prognosis. However, to date, no imaging method has been demonstrated to be effective for detecting lymphatic metastasis in GC. Molecular imaging probes based on upconversion nanoparticles with unique optical and magnetic properties have provided great hope for early tumor detection. Herein we report highly sensitive detection of lymphatic spread using core@shell structured NaGdF4:Yb,Er@NaGdF4 upconversion nanoparticles coated with polyethylene glycol (PEG). A GC-specific probe was constructed through "click" reaction between the maleimide moiety of PEG ligand and the thiol group from partly reduced antigastric cancer antibody MGb2. The primary tumor and adjacent lymphatic metastasis site were clearly differentiated by upconversion luminescence imaging after the GC-specific probe was delivered through tail vein injection into tumor-bearing mice. Moreover, lymphatic metastases smaller than 1 mm were successfully detected, owing to the ultralow background under 980 nm excitation. It has been demonstrated that both primary and lymphatic metastatic sites in an orthotopic mouse model of human gastric cancer can be optically detected by using GC-specific upconversion luminescence nanoprobes. The current studies may therefore provide a highly effective approach for GC diagnosis.

Metastasis-associated in colon cancer-1 upregulates vascular endothelial growth factor-C/D to promote lymphangiogenesis in human gastric cancer

Lymphangiogenesis is actively contributed to lymphatic metastasis in gastric cancer (GC), and vascular endothelial growth factor (VEGF)-C and VEGF-D are key regulators for lymphangiogenesis. Metastasis-associated in colon cancer-1 (MACC1) was reported to be associated with lymph node metastasis in a few clinical studies, while little is known about the role of MACC1 in lymphangiogenesis. Hence, in the present study, we explored the potential role of MACC1 in lymphangiogenesis as well as the underlying mechanisms. By clinical observation, we found a positive relationship between MACC1 and lymphangiogenesis. Besides, similar results were also obtained from in vivo and in vitro studies. With an indirect co-culture system, we got that supernatant from MACC1 overexpressed GC cells accelerated human lymphatic endothelial cells' (HLECs') capacity of tube-like formation through enhancing cell proliferation and migration. Moreover, MACC1 overexpressed xenografts also presented more lymphatic vessels. Furthermore, MACC1 significantly increased the expression of VEGF-C/VEGF-D in GC cells and transplanted tumors, which was subsequently suppressed by c-Met inhibitor. All these data suggested a critical role for MACC1 in lymphatic dissemination of GC, providing evidence that MACC1 upregulated VEGF-C/VEGF-D secretion to promote lymphangiogenesis via c-Met signaling.

Identification of microRNAs associated with lymphangiogenesis in human gastric cancer

Lymphatic metastasis is a primary cause of gastric cancer-related death, yet factors governing tumor cell lymphatic metastasis have not been fully elucidated. MicroRNAs (miRNAs) are a recently discovered class of regulatory, non-coding RNAs, some of which are involved in gastric cancer progression. However, little is known about which miRNA contributes to the lymphatic metastasis in human gastric cancer. This prompted us to find the significant miRNAs associated with lymphangiogenesis in human gastric cancer. We screened vascular endothelial growth factor C (VEGF-C) expression in several gastric cancer cell lines as well as in the immortalized human gastric mucosal cell line GES-1, by real-time reverse transcriptase PCR (qRT-PCR). The gastric cancer cell lines MKN-45 and SGC-7901, which have commonly been cultured with human lymphatic endothelial cells (HLECs) in vitro, promoted tube formation of HLECs following transformation with a VEGF-C expression vector. Using microarrays, we identified a panel of differentially expressed miRNAs in HLECs that had been co-cultured with VEGF-C-transformed gastric cancer cells compared with non-transformed gastric cancer cells. A subset of miRNAs was further validated using qRT-PCR. We found altered expression of miRNAs in HLECs co-cultured with lymphangiogenesis-inducing VEGF-C-transformed gastric cancer cells, with 47 up-regulated and 42 down-regulated miRNAs. These findings were confirmed by qRT-PCR of selected miRNAs. Furthermore, several miRNAs were differentially expressed in patients with positive lymphatic metastasis of the primary gastric tumor. Up-regulated miRNAs included miR-648, miR-5002-3p, miR-4754, miR-4760-5p, miR-4491, miR-4252, miR-5007-3p, and miR-647; and down-regulated miRNAs included miR-3178, miR-593-5p, miR-4485, miR-135a-3p, miR-17, miR-1469, and miR-124-5p. Several lymphangiogenesis-related miRNAs are significantly altered during lymphatic metastasis of gastric cancer.

Cadherin-17 induces tumorigenesis and lymphatic metastasis in gastric cancer through activation of NFκB signaling pathway

Cadherin-17 (CDH17), as a structurally unique member of the cadherin superfamily, has been identified to predict a poor prognosis for gastric cancer (GC). Our previous study demonstrated the positive correlation between CDH17 and lymph node micrometastasis in GC. We sought to further identify the role of CDH17 in the tumorigenesis and lymphatic metastasis of GC. Hence, we inhibited the CDH17 expression in MKN-45 gastric cancer cells by using RNA interference. Consequently, the malignant potency of cancer cells was evaluated, and the change in NFκB signaling pathway was also probed. Tumor growth and lymphatic metastasis model were conducted in nude mice to confirm the hypothesis. Downregulation of CDH17 not only suppressed the proliferation, adherence and invasion potency of MKN-45 cells, but also induced cell cycle arrest. Meanwhile, the NFκB signaling pathway was inactivated as well, with the reductions of downstream proteins including VEGF-C and MMP-9. Moreover, silencing CDH17 inhibited tumor growth in vivo significantly, and there was no lymph node metastasis detected in the mice without CDH17 expression, as opposed to the positive nodes found in controls. CDH17 is a novel oncogene in gastric cancer cells, which is associated with lymphatic metastasis and proliferation strongly. The inactivation of NFκB signaling pathway might be involved in targeting CDH17 in GC. On the whole, CDH17 is proposed to serve as a biomarker and attractive therapeutic target in GC.

Response letter regarding the interpretation of gene expression data

This is a response letter to Verna E's comments regarding our previous manuscript published last year in the World Journal of Gastroenterology entitled "Relationship between LYVE-1, VEGFR-3 and CD44 gene expressions and lymphatic metastasis in gastric cancer", which evaluated the relationship between these expression levels and clinicopathological parameters (Ozmen F et al, World J Gastroenterology 2011; 17: 3220-3228). The mean values for lymphatic vessel endothelial hyaluronan receptor-1, CD44 and vascular endothelial growth factor receptor-3 expression (represented as 2(-ΔΔCt)) were 1.13, 1.24 and 1.17, respectively, suggesting an increase in gene expression in tumor tissue compared to normal tissue. Despite the increase in gene expression in the cancer tissues (2(-ΔΔCt) > 1), only some of the results reached statistical significance, which was thoroughly discussed in our paper. In the present letter, we report that his comments are flawed and result in confusion. Therefore, we herein provide more explanation regarding gene expression in gastric cancer. We hope that this letter will address Verna E's misunderstandings.

Relationship between LYVE-1, VEGFR-3 and CD44 gene expressions and lymphatic metastasis in gastric cancer.

To investigate the expression levels of lymphatic vessel endothelial hyaluronan receptor-1 (LYVE-1), vascular endothelial growth factor receptor-3 (VEGFR-3) and CD44 genes and the relationship between their levels and clinicopathological parameters in gastric cancer. Tissue samples were obtained from 33 patients (8 females) with gastric cancer. mRNA levels of LYVE-1, VEGFR-3 and CD44 in normal and tumor tissues were quantitatively measured using real time polymerase chain reaction. The results were correlated with lymph node metastasis, histological type and differentiation of the tumor, T-stage, and presence of vascular, perineural and lymphatic invasions. The distribution of molecules in the tissue was evaluated using immunohistochemistry. LYVE-1, CD44 and VEGFR-3 gene expression levels were significantly higher in gastric cancer than in normal tissue. While there was no correlation between gene expressions and clinicopathologic features such as histologic type, differentiation and stage, gene expression levels were found to be increased in conjunction with positive lymph node/total lymph node ratio and the presence of perineural invasion. A significant correlation was also found between LYVE-1 and CD44 over-expressions and perineural invasion and lymph node positivity in gastric cancers. When the distribution of LYVE-1 antibody-stained lymphatic vessels in tissue was evaluated, lymphatic vessels were located intra-tumorally in 13% and peri-tumorally in 27% of the patients. Moreover, lymph node metastases were also positive in all patients with LYVE-1-staining. LYVE-1, VEGFR-3 and CD44 all play an important role in lymphangiogenesis, invasion and metastasis. LYVE-1 is a perfectly reliable lymphatic vessel marker and useful for immunohistochemistry.

Smad4/Smad7 balance: A role of tumorigenesis in gastric cancer

Smad signaling pathway plays an important role in tumorigenesis and progression in cancer (Halder, S.K., Rachakonda, G., Deane, N.G., Datta, P.K., 2008. Smad7 induces hepatic metastasis in colorectal cancer. Br. J. Cancer 99, 957–965). The protein level of Smad is associated with growth, inhibition, and metastasis in different cancers. It is unclear if the differentiation, metastasis and apoptosis are reduced by Smad expression pattern in gastric cancer. To determine the effect of Smad on gastric cancer cells, we investigated the relationship of Smad4/Smad7 expression, and differentiation, metastasis, and apoptosis in different gastric cancer. The results show that Smad4 expression in the gastric cancer tissue was dramatically lower than that in the peritumoral tissue. A lower expression of Samd4 was significantly lower in the poorly differentiated tissue than that in the well and middle differentiated tissues ( P < 0.01). In contrast, Smad7 expression in gastric cancer tissues was significantly higher than that in the peritumoral tissue. Smad7 was overexpressed in poorly differentiated tissue, also higher than those in the middle, and well differentiated tissues ( P < 0.05). The Smad4 or Smad7 expression obviously related with the lymphatic metastasis in gastric cancer. There were 45 cases with lymphatic metastasis in all 78 patients. Smad4 expression in the cases with lymphatic metastasis was lower than the cases without metastasis ( P < 0.01), whereas Smad7 expression in the cases with lymphatic metastasis was much higher than the case without metastasis ( P < 0.01). To better understand the mechanisms involved in tumorigenesis of gastric cancer, we established SGC7901 gastric cancer cell lines transduced with Smad4 or Smad7 plasmid DNA. Apoptosis and survival of cancer cells was induced after Smad4 and Smad7 transduction. This effect is concentration and time dependent. Thus, this study provides a mechanism by which a balance between Smad4 and Smad7 in human gastric cancer is critical for differentiation, metastasis, and apoptosis of tumor cells.

Relationship between preoperative staging by endoscopic ultrasonography and MMP-9 expression in gastric carcinoma

To investigate the relationship between the staging by endoscopic ultrasonography (EUS) and the expression of carcinoma metastasis associated gene in the patients with gastric carcinoma. Sixty-three patients with gastric cancer were diagnosed by electric gastroscopy and EUS. The preoperative staging of gastric cancer was measured by EUS and compared with pathologic staging and MMP-9 expression. Peripheral serum level of MMP-9 was measured with enzyme-linked immunosorbent assay (ELISA), while the expression of MMP-9 protein was tested with immunohistochemistry and hybridization in situ in the gastric carcinoma tissues. The total accuracy of EUS in estimating invasive depth of gastric cancer was 80.95%, while that in estimating lymphatic metastasis was 73.02%. Serum MMP-9 levels were consistent with the expression of MMP-9 protein and MMP-9 mRNA in tissue, a result closely correlated with invasive degree, staging with EUS and lymphatic metastasis in gastric cancer (P<0.05). The total accuracy of estimating invasive depth in gastric cancer was 95.22% using both EUS and MMP-9. The MMP-9 level of preoperative serum presents the reference value for preoperative staging by EUS in the patients with gastric cancer. When serum MMP-9 level in gastric cancer is significantly high, physicians should pay closer attention to the metastasis which reaches the serosa or beyond. Combining EUS and MMP-9 improves the accuracy in deciding the invasion and metastasis in the patients with gastric carcinoma.

Changes of trace elements in regional lymph nodes of gastric carcinoma

To explore the relationship between the changes of trace elements and lymphatic metastasis in gastric carcinoma. Trace elements including Fe, Mg, Mn, Ca, Cu, Zn, Se were measured in primary gastric carcinoma and regional lymph nodes from 40 patients with gastric carcinoma, and compared among the primary tumor, metastatic, and non-metastatic nodes. There were no significant differences in the contents of Fe, Mg, Mn and Ca among primary gastric tumors, regional lymph nodes with or without metastasis (P=0.372 - 0.741, P > 005), and no significant differences in the contents of all 7 trace elements between primary tumors and metastatic lymph nodes (P=0.15 - 0.59, P > 005). Compared with metastatic lymph nodes, the contents of Zn, Se significantly decreased, while Cu and Cu/Zn significantly increased (P=0.001 - 0.009, P< 0.01) in non-metastatic lymph nodes. The content of Zn in N2 positive lymph nodes was significant lower than that in N1 positive nodes (P=0.027). There were no significant difference in the contents of all 7 elements between intestinal type and diffuse type (P=0.149 - 0.758, P > 0.05). Lymphatic metastasis of gastric cancer is concomitant with the changes of trace elements, and the changes of Zn, Cu, Se may be related with lymphatic metastasis.

Relationship between lymph node sinuses with blood and lymphatic metastasis of gastric cancer.

To elucidate the relationship between lymph node sinuses with blood and lymphatic metastasis of gastric cancer. Routine autopsy was carried out in the randomly selected 102 patients (among them 100 patients died of various diseases, and 2 patients died of non-diseased reasons), their superficial lymph nodes locating in bilateral necks (include supraclavicle), axilla, inguina, thorax, and abdomen were sampled. Haematoxylin-Eosin staining was performed on 10 % formalin-fixed and paraffin-embedded lymph node tissue sections (5 um). The histological patterns of the lymph sinuses containing blood were observed under light microscope. The expression of CD31, a marker for endothelial cell, was detected both in blood and non-blood containing lymph node sinuses with the method of immunohistochemistry. Among the 1 322 lymph nodes sampled from the autopsies of 100 diseased cases, lymph node sinuses containing blood were found in 809 lymph nodes sampled from 91 cases, but couldn't be seen in the lymph nodes sampled from the non-diseased cases. According to histology, we divided the blood containing lymph node sinuses into five categories: vascular-opening sinus, blood-deficient sinus, erythrophago-sinus, blood-abundant sinus, vascular-formative sinus. Immunohistochemical findings showed that the expression of CD31 was strongly positive in vascular-formative sinuses and some vascular-opening sinuses while it was faint in blood-deficient sinuses, erythrophago-sinuses and some vascular-opening sinuses. It was almost negative in blood-abundant sinus and non-blood containing sinus. In the state of disease, the phenomenon of blood present in the lymph sinus is not uncommon. Blood could possibly enter into the lymph sinuses through the lymphaticovenous communications between the veins and the sinuses in the node. Lymph circulation and the blood circulation could communicate with each other in the lymph node sinuses. The skipping and distal lymphatic metastasis of gastric cancer may have some connection with the blood containing lymph node sinuses.

Macroscopic Findings and Lymphatic Metastasis of Gastric Cancer Infiltrating into Tunica Muscularis Propria

Macroscopic Findings and Lymphatic Metastasis of Gastric Cancer Infiltrating into Tunica Muscularis Propria