Meta-analysis of Robot-assisted Versus Laparoscopic Surgery for Rectal Cancer

BACKGROUND/AIM

A meta-analysis was conducted to evaluate and compare the short- and long-term outcomes of robot-assisted (RAS) and conventional laparoscopic surgery (LAS) for rectal cancer.

MATERIALS AND METHODS

We searched MEDLINE for relevant papers published between 2010 and December 2017 by using specific search terms. We analyzed outcomes over short- and long-term periods.

RESULTS

We identified 23 papers reporting results that compared RAS for rectal cancer with LAS. Our meta-analysis included 4,348 patients with rectal cancer; 2,068 had undergone RAS, and 2,280 had undergone LAS. In the short- and long-term period, 27 and 7 outcome variables were examined, respectively. RAS for rectal cancer was significantly associated with a greater operative time and a lower conversion rate to open surgery in the short-term, and results in almost similar outcomes in the long-term, compared to LAS.

CONCLUSION

RAS may be an acceptable surgical treatment option compared to LAS for rectal cancer.

[Two cases of esophageal variceal rupture associated with chemotherapy for liver metastasis of breast cancer]

A morphological change resembling liver cirrhosis called pseudocirrhosis may be observed following chemotherapy for liver metastasis of breast cancer. Pseudocirrhosis is hypothesized to be caused by retraction of the hepatic capsule along with tumor shrinkage and subsequent scar formation around the metastatic lesion, as a response to the infiltrating tumor or chemotherapy-induced hepatic injury. The progression of cirrhotic changes may result in portal hypertension and esophageal varices. We managed two cases of esophageal variceal rupture during chemotherapy for breast cancer with liver metastasis. Hemostasis was successfully achieved by the endoscopic variceal ligation technique in both cases. We conclude that clinicians should be aware of the risk of pseudocirrhosis during chemotherapy for liver metastasis, and a periodic endoscopic follow-up is recommended along with appropriate management of esophageal varices.

[A case of solitary adrenal metastasis from breast cancer successfully resected by laparoscopy]

A 47-year-old woman had undergone breast-conserving treatment for right breast cancer (T3, N1, M0, Stage IIIA, human epidermal growth factor receptor[ HER]-2 enriched subtype) after primary systemic chemotherapy with trastuzumab. Pathological examination revealed a quasi-pathological complete response( CR) in the breast tumor and no axillary nodal involvement. The patient then received conventional breast irradiation and adjuvant trastuzumab therapy. However, adjuvant anti- HER2 therapy was discontinued in the 19th week because of a decreased left ventricular ejection fraction( approximately 50%). A left adrenal tumor was detected by abdominal computed tomography (CT) 2 years after surgery. Positron emission tomography( PET) scans showed strong accumulation in the left adrenal gland and in the lymph node near the adrenal tumor. No other obvious lesion was detected on meticulous examination. Laparoscopic adrenalectomy was performed for diagnosis and treatment. Pathological examination of the resected specimen revealed that the tumor was a metastatic adenocarcinoma with overexpression of the HER2 protein but without expression of hormonal receptors. The patient received 12 cycles of chemotherapy with paclitaxel and trastuzumab, which was followed by trastuzumab monotherapy. However, trastuzumab monotherapy could not be continued because the left ventricular ejection fraction decreased to 50% at 24 weeks after initiation of chemotherapy. The patient has been observed since the cessation of trastuzumab, without the administration of anticancer therapy, and she continues to have a good performance status without relapse. Herein, we report a case of solitary adrenal metastasis from breast cancer, an extremely rare condition, and review the relevant literature.

[Successful treatment of locally advanced squamous cell carcinoma of the esophagus by combination chemotherapy with 5-fluorouracil plus nedaplatin following tracheal stent tube placement-a case report]

The patient was a 68-year-old man who complained of hoarseness and dyspnea. Upper gastrointestinal endoscopy revealed a type 3 tumor located in the middle thoracic esophagus at 30 cm from the incisor tooth that involved one-fourth of the circumference of the esophagus. Histopathological examination revealed moderately differentiated squamous cell carcinoma. Chest computed tomography( CT) revealed severe tracheal stenosis due to compression by a metastatic lymph node along the left recurrent laryngeal nerve. The patient was diagnosed as having cT4( 106recL-trachea), N2( 101L, 106recL, 106recR), M0, Stage IVa unresectable esophageal carcinoma. After insertion of a tracheal stent tube( spiral Z stent: diameter, 18 mm; length, 80 mm) to improve dyspnea, combination chemotherapy with 5-fluorouracil( 5-FU) plus nedaplatin was administered. Subsequent CT and endoscopy showed that the main tumor and the metastatic lymph node had significantly reduced in size and that complete response (CR) had been achieved. Thirty months after the initial treatment, the patient showed no sign of disease recurrence, after completion of 19 cycles of chemotherapy. The patient did not experience any severe adverse events. We report a case of a patient with locally advanced squamous cell carcinoma of the esophagus successfully treated with 5-FU/nedaplatin combination chemotherapy following tracheal stent tube placement.

Hypoxia stimulates the EMT of gastric cancer cells through autocrine TGFβ signaling

Epithelial mesenchymal transition (EMT) is considered to be correlated with malignancy of cancer cells and responsible for cancer invasion and metastasis. We previously reported that distant metastasis was associated with hypoxia in gastric cancer. We therefore investigated the effect of hypoxic condition on EMT of gastric cancer cells. Gastric cancer cells were cultured in normoxia (21% O₂) or hypoxia (1% O₂) for 24 h. EMT was evaluated as the percentage of spindle-shaped cells in total cells. Effect of transforming growth factor β1 (TGFβ1) or tyrosine kinase inhibitors on the EMT was evaluated. The expression level of TGFβ1 and TGFβR was evaluated by real time RT-PCR. The TGFβ1 production from cancer cells was measured by ELISA. Hypoxia stimulated EMT of OCUM-2MD3 and OCUM-12 cells, but not that of OCUM-2M cells. The expression level of TGFβ1 mRNA under hypoxia was significantly higher than that under normoxia in all of three cell lines. The expression level of TGFβR mRNA was significantly increased by hypoxia in OCUM-2MD3 cells, but not in OCUM-2M cells. TGFβR inhibitor, SB431542 or Ki26894, significantly suppressed EMT of OCUM-2MD3 and OCUM-12. TGFβ1 production from OCUM-2MD3 and OCUM-12 cells was significantly increased under hypoxia in comparison with that under normoxia. These findings might suggest that hypoxia stimulates the EMT of gastric cancer cells via autocrine TGFβ/TGFβR signaling.

RhoA/ROCK signaling mediates plasticity of scirrhous gastric carcinoma motility

The small guanosine triphosphatase (GTPase) Rho and its downstream effector Rho-associated kinase (ROCK) is one of a key mediator involved in controlling focal adhesions and the dynamics of actin stress fibers. The molecular mechanisms for the function of Rho/ROCK pathway leading to the progression in scirrhous gastric carcinoma cells have not been defined. The activation of RhoA in several gastric carcinoma cells was examined. The role of RhoA/ROCK pathway in the metastatic processes of gastric carcinoma cells, using a human scirrhous gastric cancer cell line, OCUM-2MD3 was investigated by in vitro adhesion and invasion assay. The effect of ROCK inhibitor, Y-27632 on the mRNA expression of the integrin family and MMP in gastric carcinoma cells was subsequently examined by Reverse transcriptional (RT)-PCR analysis. Finally, Random OCUM-2MD3 cell motility was evaluated using Time-lapse microscopy. ROCK inhibitor significantly increased the adhesion of OCUM-2MD3 cells to the extracellular matrix (ECM) protein matrigel. Further examination using ECM components showed enhanced binding ability was obtained only in laminin and Integrin subunits α3-integrin was clearly up-regulated by treatment with Y-27632 in OCUM-2MD3 cells. ROCK inhibitor also enhanced the invasion of OCUM-2MD3 cells through matrigel and the expression of membrane-type 1 matrix metalloproteinase (MT1-MMP). Time-lapse microscopy showed conversion of OCUM-2MD3 cells from round to more elongated morphology in the presence of Y-27632, suggesting that inhibition of RhoA/ROCK pathway undergo a so-called 'amoeboid to mesenchymal' transition. The fact that Rac1 inhibitor decreased the facilitated invasion by ROCK inhibitor suggested the possibility that increased invasion ability of OCUM-2MD3 cells was related to Rac activity. These data may suggest that RhoA/ROCK regulate plasticity of metastatic gastric carcinoma via mesenchymal-amoeboid transition, leading to provide new insights for designing a new and effective treatment for this type of refractory carcinoma.

Borrmann's macroscopic criteria and p-Smad2 expression are useful predictive prognostic markers for cytology-positive gastric cancer patients without overt peritoneal metastasis

BACKGROUND

All patients with peritoneal-free cancer cells (CY1) do not always develop a peritoneal recurrence (P1). The goal of this study was to identify characteristic features of peritoneal-free cancer cells that could develop into peritoneal recurrence.

METHODS

Of 1,474 patients, 91 were identified with CY1P0, and the remaining 1,383 with CY0P0. Immunohistochemical staining with anti-phosphorylated Smad 2 (p-Smad2) was performed on paraffin-embedded specimens from the 91 CY1P0 patients.

RESULTS

CY1 was significantly correlated with Borrmann's type-4 cancer, clinical T stage, and lymph node metastasis. CY1P0 patients with Borrmann's type-4 cancer more frequently develop peritoneal recurrence than do those with other types of tumors. The 5-year survival rate of patients with Borrmann's type-4 tumors was significantly (p = 0.023) low (6.3%) compared with that of patients with other types of tumors (27.7%). The prognosis for p-Smad2-positive patients was significantly poorer than that of p-Smad2-negative patients. In CY1 and/or P1 patients with Borrmann's type-4 tumors, no significant difference in prognosis was identified between those who had surgery and those who did not.

CONCLUSIONS

Activated Smad signaling might be associated with a high potential for peritoneal recurrence in CY1P0 patients. Borrmann's macroscopic criteria and p-Smad2 expression are useful markers for surgeons selecting advanced gastric cancer patients with CY1P0 for gastrectomy.

Abstract 2552: Synergistic antitumor effects of FGFR2 inhibitor with 5-fluorouracil on diffuse-type gastric carcinoma

Purpose: Diffuse-type gastric carcinoma carries the highest mortality because of a frequent metastasis to lymph node. S1, a 5-fluorouracil (5-FU) analog, is clinically available for gastric cancer at advanced stage. Fibroblast growth factor receptor 2 (FGFR2) is required for the proliferation of diffuse-type gastric carcinoma. The objective of this study is to clarify the benefit of a combination of S1 and kinase inhibitors including FGFR2 inhibitor Ki23057 in gastric cancer.

Experimental Design: OCUM-2MLN and KATO-III were derived from diffuse-type gastric carcinoma. MKN-7 and MKN-74 were derived from intestinal-type gastric carcinoma. MTT assay was used to examine the growth-inhibitory activity of 5 small-synthetic molecules including Ki23057, Sunitinib, Glivec, Lapatinib, or SU11274, in cells cultured with 5-FU. Combination effects of 5-FU with Ki23057 on proliferation, apoptosis, and mRNA expression were examined. S1 and/or Ki23057 were administered to murine models of diffuse-type gastric carcinoma created by the orthotopic inoculation of OCUM-2MLN cells.

Results: Ki23057 at 100 nM significantly (p<0.01) inhibited the proliferation, and decreased the phosphorylation of FGFR2 in diffuse-type gastric carcinoma cells, but not in intestinal-type gastric carcinoma. Ki23057 showed synergistic anti-tumor effects for diffuse-type gastric carcinoma cells in combination with 5-FU using CalcuSyn analysis, but Sunitinib, Glivec, Lapatinib, and SU11274 did not. The combination of Ki23057 and 5-FU decreased DPD expression, and increased apoptosis rates, and p21 expression level of diffuse-type gastric carcinoma cells. The combined administration of S1 and Ki23057 significantly (p<0.05) decreased orthotopic tumors as well as lymph node metastasis more effectively than S1 alone.

Conclusion: The combined treatment with 5-FU and Ki23057 produced synergistic anti-tumor effects, and is a therapeutically promising for diffuse-type gastric carcinoma treatment.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 2552. doi:10.1158/1538-7445.AM2011-2552

Transforming growth factor β signaling inhibitor, SB-431542, induces maturation of dendritic cells and enhances anti-tumor activity

The transforming growth factor β (TGFβ) stimulates tumor progression and metastasis. Secretion of TGFβ by tumor cells also suppresses an antitumor immune response in which dendritic cells (DCs) play an important role to activate cytotoxic T lymphocytes (CTLs). Herein we report that the small molecule TGFβ signaling inhibitor SB-431542, induces DC maturation in vitro and triggers antitumor activity in vivo. We added SB-431542 to cultures of murine bone-marrow derived DCs (BM-DCs) derived from BALB/c mice and human DCs generated from peripheral monocytes (human DCs) at different concentrations in triplicates and examined expression of co-stimulatory molecules by FACS and production of Interleukin-12 (IL-12) by ELISA. SB induced phenotypic maturation of BM-DCs and human DCs and improved their abilities to produce IL-12 in a dose-dependent manner. SB-431542 also augmented capacity of murine and human DCs to activate naive T cells in allogeneic mixed lymphocyte reaction. Interestingly, SB-431542 augmented the capacity of BM-DCs and human DCs to incorporate FITC-conjugated dextran. Intraperitoneal administration of SB-431542 initiated 3 and 7 days after the implantation of colon-26 cancer cells into the peritoneal cavity of BALB/c mice significantly induced CTL activity against colon-26. We incubated human DCs with SB-431542 and cell lysate of scirrhous gastric cancer cell line OCUM-8, and then examined CTL activities against OCUM-8. CD8 T cells activated by human DCs treated with SB-431542 showed modest augmentation CTL activity against cancer cells. Furthermore, pretreatment of human DCs with SB-431542 upregulated cytotoxic activity against K562 cells, suggesting SB should have potential to activate DCs to natural killer cells. In conclusion, TGFβ receptor I kinase inhibitor such as SB-431542 might induce anti-tumor immune response in immuno-tolerant patients associated with TGFβ activity.

Phosphorylated smad2 in advanced stage gastric carcinoma

BACKGROUND

Transforming growth factor β (TGFβ) receptor signaling is closely associated with the invasion ability of gastric cancer cells. Although Smad signal is a critical integrator of TGFβ receptor signaling transduction systems, not much is known about the role of Smad2 expression in gastric carcinoma. The aim of the current study is to clarify the role of phosphorylated Smad2 (p-Smad2) in gastric adenocarcinomas at advanced stages.

METHODS

Immunohistochemical staining with anti-p-Smad2 was performed on paraffin-embedded specimens from 135 patients with advanced gastric adenocarcinomas. We also evaluated the relationship between the expression levels of p-Smad2 and clinicopathologic characteristics of patients with gastric adenocarcinomas.

RESULTS

The p-Smad2 expression level was high in 63 (47%) of 135 gastric carcinomas. The p-Smad2 expression level was significantly higher in diffuse type carcinoma (p = 0.007), tumours with peritoneal metastasis (p = 0.017), and tumours with lymph node metastasis (p = 0.047). The prognosis for p-Smad2-high patients was significantly (p = 0.035, log-rank) poorer than that of p-Smad2-low patients, while a multivariate analysis revealed that p-Smad2 expression was not an independence prognostic factor.

CONCLUSION

The expression of p-Smad2 is associated with malignant phenotype and poor prognosis in patients with advanced gastric carcinoma.

[A long-term survival case of unresectable intrahepatic cholangiocarcinoma treated with chemotherapy]

An 83-year-old man commuting to our hospital with postoperative ascending colon cancer was pointed out an increase of CA19-9. CT scan revealed an intrahepatic cholangiocarcinoma in the left lobe. In May 2007, an operation was performed. We recognized a lymph node swelling in the hepatoduodenal ligament. Pathologically, it was moderately differentiated adenocarcinoma. Therefore, the operation did only the cholecystectomy. Gemcitabine was administered once a week for 3 weeks followed by a week rest. It was administered for about 20 months and the evaluation during the period was PR or SD. Afterwards, the tumor had increased gradually. Gemcitabine was changed to S-1. Then, S-1 was changed to gemcitabine again because the enlargement of the tumor and the rise of tumor markers were observed. Consequently, tumor markers decreased. Now, the patient is under an outpatient care maintaining ADL.

Combination effect of a TGF-beta receptor kinase inhibitor with 5-FU analog S1 on lymph node metastasis of scirrhous gastric cancer in mice

Transforming growth factor-beta (TGF-beta) signals are closely associated with the distant metastases of gastric cancer. The aim of this study was to clarify the effect of a TGF-beta receptor I (TbetaR-I) phosphorylation inhibitor, Ki26894, in combination with anticancer drugs, on the lymph node (LN) metastasis of scirrhous gastric cancer. A novel TbetaR-I kinase inhibitor, Ki26894, inhibits the phosphorylation of Smad2 at the ATP binding site of TbetaR-I. S1 is a 5-fluorouracil analog. The human scirrhous gastric cancer cell line OCUM-2MLN and the human gastric fibroblasts NF-33 were used. OCUM-2MLM cells in the upper well and NF-33 cells in the lower well were co-incubated with or without Ki26894. The proliferation of OCUM-2MLN cells was significantly stimulated by co-culture with NF-33 cells. Ki26894 significantly suppressed the growth interactions between OCUM-2MLN cells and NF-33 cells. Gastric cancer models established by orthotopic inoculation of OCUM-2MLN cells showed diffusely infiltrating gastric adenocarcinoma accompanied by LN metastases. We divided these mice into four groups, (control vehicle, Ki26894, S1, Ki26894 plus S1), and examined the effect of Ki26894 and/or S1 on phosphorylation of Smad2, tumor size, LN metastases, and lymphatic involvements. Ki26894 inhibited the Smad2 phosphorylation of cancer cells and decreased the extent of lymphatic involvement, compared with the control or S1 only group. The Ki26894 plus S1 administration group significantly suppressed tumor growth and decreased LN metastasis more effectively than either alone. These findings suggested that the TbetaR-I kinase inhibitor with S1 is useful for the treatment of scirrhous gastric carcinoma with LN metastasis. (Cancer Sci 2010).

Abstract 1566: Effects of VEGFR-3 phosphorylation inhibitor on lymph node metastasis in diffuse-type gastric carcinoma

Background: Vascular endothelial growth factor receptor-3 (VEGFR-3) signaling mediates lymphangiogenesis and lymphatic invasion, however the effect of VEGFR-3 inhibition on the lymph node (LN) metastasis remains unclear. The aim of this study is to clarify the benefit of a VEGFR-3 inhibitor Ki23057 for LN metastasis.

Methods: Ki23057 was administered orally to gastric cancer models created by orthotopic inoculation of diffuse-type gastric cancer cells, OCUM-2MLN. Effects of Ki23057 on lymphatic vessel invasion, lymphatic vessel density, and VEGFR-3 phosphorylation were examined by immunostaining or immunoblotting.

Results: Ki23057 inhibited the autophosphorylation of VEGFR-3 with IC50 values of 4.3 nM in the cell-free kinase assay. Murine gastric cancer models created by the orthotopic inoculation of OCUM-2MLN cells showed the diffusely infiltrating growth and frequently developed LN metastasis. The oral administration of Ki23057 significantly (p<0.01) reduced the size of orthotopic tumors and the number of the metastatic LN in gastric cancer models. The degree of lymphatic invasion and lymphangiogenesis was significantly (p<0.05) lower in the gastric tumors treated by Ki23057. Ki23057 inhibited the phosphorylation of VEGFR-3 of lymphatic endothelial cells in gastric tumors.

Conclusion: The inhibition of lymphangiogenesis targeting VEGFR-3 phosphorylation is a therapeutic strategy for inhibiting LN metastasis of diffuse-type gastric cancer.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 1566.

Abstract 5118: Rho/ROCK pathway mediates plasticity of scirrhous gastric carcinoma cell motility

The small guanosine triphosphatase (GTPase) Rho and its downstream effector Rho-associated kinase (ROCK) is one of a key mediator involved in controlling focal adhesions and the dynamics of actin stress fibers. This pathway has been shown to play important roles in the regulation of various cellular processes, such as cell shape changes and adhesion dynamics that drive migration. The underlying molecular mechanisms for the function of Rho/ROCK pathway leading to the development and progression in scirrhous gastric carcinoma cells have not been defined. We investigated the role of the Rho/ROCK pathway in the adhesion and invasion of gastric carcinoma cells, using a human scirrhous gastric cancer cell line, OCUM-2MD3. ROCK inhibitor, Y27632 significantly increased the adhesion of OCUM-2MD3 cells to the extracellular metrix (ECM) protein matrigel, but had no effect on attachment to polylysine. Further examination using ECM components showed enhanced binding ability was obtained only in laminin, but not in fibronectin, Type I collagen, and Type IV collagen. Reverse transcriptional (RT)-PCR analysis revealed that integrin subunits α3-integrin was clearly up-regulated by treatment with Y-27632 in OCUM-2MD3 cells, reflecting the specificity of ECM protein showing high adhesiveness property of gastric carcinoma cells. ROCK inhibitor also enhanced the invasion of OCUM-2MD3 cells through matrigel. The fact that Y27632 up-regulated the expression of membrane-type 1 matrix metalloproteinase by RT-PCR suggested the possibility that increased invasion ability of OCUM-2MD3 cells was related to proteolytic activity of extracellular matrices. Time-lapse microscopy showed conversion of OCUM-2MD3 cells from elongated to more round morphology with bleb in the presence of Y27632, suggesting that inhibition of Rho/ROCK pathway undergo a so-called ‘amoeboid to mesenchymal’ transition. Taken together, these data suggests that Rho/ROCK regulate plasticity of metastatic gastric carcinoma via mesenchymal-amoeboid transition, leading to clarify the specific progression of scirrhous gastric carcinoma.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 5118.

Plasma pharmacokinetics after combined therapy of gemcitabine and oral S-1 for unresectable pancreatic cancer

Background

The combination of gemcitabine (GEM) and S-1, an oral 5-fluorouracil (5-FU) derivative, has been shown to be a promising regimen for patients with unresectable pancreatic cancer.

Methods

Six patients with advanced pancreatic cancer were enrolled in this pharmacokinetics (PK) study. These patients were treated by oral administration of S-1 30 mg/m² twice daily for 28 consecutive days, followed by a 14-day rest period and intravenous administration of GEM 800 mg/m² on days 1, 15 and 29 of each course. The PK parameters of GEM and/or 5-FU after GEM single-administration, S-1 single-administration, and co-administration of GEM with pre-administration of S-1 at 2-h intervals were analyzed.

Results

The maximum concentration (Cmax), the area under the curve from the drug administration to the infinite time (AUCinf), and the elimination half-life (T1/2) of GEM were not significantly different between GEM administration with and without S-1. The Cmax, AUCinf, T1/2, and the time required to reach Cmax (Tmax) were not significantly different between S-1 administration with and without GEM.

Conclusion

There were no interactions between GEM and S-1 regarding plasma PK of GEM and 5-FU.

Inhibitory effect of a TGFbeta receptor type-I inhibitor, Ki26894, on invasiveness of scirrhous gastric cancer cells

Background:

Gastric cancer cells frequently metastasise, partly because of their highly invasive nature. Transforming growth factor-β (TGF-β) receptor signalling is closely associated with the invasion of cancer cells. The aim of this study was to clarify the effect of a TGF-β receptor (TβR) phosphorylation inhibitor on the invasiveness of gastric cancer cells.

Methods:

Four gastric cancer cell lines, including two scirrhous-type cell lines and two non-scirrhous-type cell lines, were used. A TβR type I (TβR-I) kinase inhibitor, Ki26894, inhibits the phosphorylation of Smad2 at an ATP-binding site of TβR-I. We investigated the expression levels of TβR and phospho-Smad2, and the effects of TGF-β in the presence or absence of Ki26894 on Smad2 phosphorylation, invasion, migration, epithelial-to-mesenchymal transition (EMT), Ras homologue gene family member A (RhoA), ZO-2, myosin, and E-cadherin expression of gastric cancer cells.

Results:

TβR-I, TβR-II, and phospho-Smad2 expressions were found in scirrhous gastric cancer cells, but not in non-scirrhous gastric cancer cells. Ki26894 decreased Smad2 phosphorylation induced by TGF-β1 in scirrhous gastric cancer cells. Transforming growth factor-β1 upregulated the invasion, migration, and EMT ability of scirrhous gastric cancer cells. Transforming growth factor-β1 significantly upregulated the activity of RhoA and myosin phosphorylation, whereas TGF-β1 decreased ZO-2 and E-cadherin expression in scirrhous gastric cancer cells. Interestingly, Ki26894 inhibited these characteristics in scirrhous gastric cancer cells. In contrast, non-scirrhous gastric cancer cells were not affected by TGF-β1 or Ki26894 treatment.

Conclusion:

A TβR-I kinase inhibitor decreases the invasiveness and EMT of scirrhous gastric cancer cells. Ki26894 is therefore considered to be a promising therapeutic compound for the metastasis of scirrhous gastric carcinoma.

Synergistic antitumor effects of FGFR2 inhibitor with 5-fluorouracil on scirrhous gastric carcinoma

Scirrhous gastric carcinoma (SGC) carries the highest mortality because of a frequent metastasis to lymph node (LN). S1, a 5-fluorouracil (5-FU) analog, is clinically available for gastric cancer at an advanced stage. Fibroblast growth factor receptor 2 (FGFR2) is required for the proliferation of SGC. The objective of this study is to clarify the benefit of a combination of S1 and kinase inhibitors including FGFR2 inhibitor Ki23057 in gastric cancer. OCUM-2MLN and KATO-III were derived from SGC. MKN-7 and MKN-74 were derived from non-SGC. MTT assay was used to examine the growth-inhibitory activity of 5 small-synthetic molecules including Ki23057, Sunitinib, Glivec, Lapatinib or SU11274, in cells cultured with 5-FU. Combination effects of 5-FU with Ki23057 on proliferation, apoptosis and mRNA expression were examined. S1 and/or Ki23057 were administered to murine models of SGC created by the orthotopic inoculation of OCUM-2MLN cells. Ki23057 at 100 nM significantly (p < 0.01) inhibited the proliferation and decreased the phosphorylation of FGFR2 in SGC cells, but not in non-SGC. Ki23057 showed synergistic antitumor effects for SGC cells in combination with 5-FU using CalcuSyn analysis, but Sunitinib, Glivec, Lapatinib and SU11274 did not. The combination of Ki23057 and 5-FU decreased DPD expression and increased apoptosis rates and p21 expression level of SGC cells. The combined administration of S1 and Ki23057 significantly (p < 0.05) decreased orthotopic tumors as well as LN metastasis more effectively than S1 alone. These findings suggested that the combined treatment with 5-FU and Ki23057 produced synergistic antitumor effects and is therapeutically promising for SGC treatment.

In vitro and in vivo evidence that a combination of lapatinib plus S-1 is a promising treatment for pancreatic cancer

Lapatinib is a small molecule inhibitor of both HER2 and the epidermal growth factor receptor (EGFR). We investigated the effect of treatment with lapatinib alone or in combination with a fluoropyrimidine derivative S-1 against pancreatic cancer. The HER2/EGFR expression in each of the four pancreatic cancer cell lines MiaPaca-2, PANC-1, Capan-1 and Capan-2 was measured by flow cytometry. The anti-tumor effects of lapatinib (30 mg/kg) and/or S-1 (10 mg/kg) were evaluated using female BALB/c nude mice xenografts generated using these four cell lines. Synergy between lapatinib and S-1 was examined by median effect analysis in vitro. Resected pancreatic cancer tissues from 137 patients were immunohistochemically stained with anti-human HER2 and EGFR antibodies. The administration of lapatinib as a single agent substantially suppressed tumor growth in vivo of all pancreatic cancer cell lines examined. A strong correlation was observed between HER2 expression and the anti-tumor effect of lapatinib in vivo. Lapatinib synergized with S-1 to inhibit the tumor growth of MiaPaca-2 and PANC-1 xenografts. When used as a single agent in vitro, lapatinib barely inhibit the cell growth of any cell line. However, lapatinib synergized with the anti-tumor activity of the S-1 components 5-fluorouracil and 5-chloro-2,4-dihydrogenase against all cell lines. Immunohistochemical staining demonstrated that 70% of the pancreatic cancers overexpressed HER2 and/or EGFR. Both lapatinib monotherapy and combined treatment with S-1 may be promising treatments for patients with pancreatic cancers; the majority these cancers express lapatinib target molecules.

Effects of VEGFR-3 phosphorylation inhibitor on lymph node metastasis in an orthotopic diffuse-type gastric carcinoma model

BACKGROUND

Vascular endothelial growth factor receptor-3 (VEGFR-3) signalling mediates lymphangiogenesis and lymphatic invasion; however, the effect of VEGFR-3 inhibition on the lymph node (LN) metastasis remains unclear. The aim of this study is to clarify the benefit of a VEGFR-3 inhibitor Ki23057 for LN metastasis.

METHODS

Ki23057 was administered orally to gastric cancer models created by orthotopic inoculation of diffuse-type gastric cancer cells, OCUM-2MLN. The effects of Ki23057 on lymphatic vessel invasion, lymphatic vessel density, and VEGFR-3 phosphorylation were examined by immunostaining or immunoblotting.

RESULTS

Ki23057 inhibited the autophosphorylation of VEGFR-3, with IC50 values of 4.3 nM in the cell-free kinase assay. Murine gastric cancer models created by the orthotopic inoculation of OCUM-2MLN cells showed the diffusely infiltrating growth and frequently developed LN metastasis. The oral administration of Ki23057 significantly (P<0.01) reduced the size of orthotopic tumours and the number of the metastatic LN in gastric cancer models. The degree of lymphatic invasion and lymphangiogenesis was significantly (P<0.05) lower in the gastric tumours treated by Ki23057. Ki23057 inhibited the phosphorylation of VEGFR-3 of lymphatic endothelial cells in gastric tumours.

CONCLUSION

The inhibition of lymphangiogenesis targeting VEGFR-3 phosphorylation is a therapeutic strategy for inhibiting LN metastasis of diffuse-type gastric cancer.

Expression of ERas oncogene in gastric carcinoma

BACKGROUND

Embryonic stem cell expressed Ras (ERas) oncogene is associated with the tumorigenicity of embryonic stem cells. The aim of this study was to clarify the significance of ERas expression in clinical samples of gastric carcinomas.

MATERIALS AND METHODS

Three hundred and few tissues from gastric cancer patients were analyzed by immunohistochemical techniques using an anti-ERas antibody. ERas mRNA expression in 77 gastric carcinomas was examined by reverse-transcription polymerase chain reaction.

RESULTS

ERas expression was positive in 135 (44%) of 304 gastric carcinomas. ERas-positive expression had a significant relationship with invasion depth (p<0.01), histological type (p<0.01), clinical stage (p=0.013) and curability (p=0.001). Prognosis of ERas-negative patients was significantly (p=0.029) poorer than that of ERas-positive patients, while ERas was not an independent prognostic factor. Expression of ERas mRNA was found in 35 (45%) out of 77 gastric cancer tissues.

CONCLUSION

ERas oncogene is associated with the tumorigenic process of human gastric carcinomas.

Cancer stem cell-like SP cells have a high adhesion ability to the peritoneum in gastric carcinoma

Cancer stem cells (CSCs) are considered to be responsible for cancer metastasis, but the evidence to conclusively prove this hypothesis remains uncertain. The side population (SP), as evaluated by a flow cytometric analysis using Hoechst 33342, has been known as CSC-rich population. The aim of this study was to clarify the characterization of the SP cells in peritoneal metastasis of gastric carcinoma. Gastric cancer cell lines OCUM-2M, OCUM-2D, and OCUM-2MD3 (a daughter cell line with high potential for peritoneal metastasis) were used. We isolated SP cells from OCUM-2M and OCUM-2D using flow cytometry. Serial sorting was performed three times to enrich SP cells, and they were designated as OCUM-2M/SP and OCUM-2D/SP cells. Flow cytometric analysis showed 0.46%, 0.29%, 5.24%, 6.49%, and 11.3% of the SP cells to be found in OCUM-2M, OCUM-2D, OCUM-2MD3, OCUM-2M/SP, and OCUM-2D/SP cells, respectively. The intraperitoneal inoculation of SP cells and OCUM-2MD3 cells produced peritoneal metastasis, but parent cells did not. The adhesion ability of SP and OCUM-2MD3 cells was significantly high in comparison to that of parent cells. The expression level of adhesion molecules alpha2-, alpha5-, beta3-, and beta5-integrin, and CD44, was high in SP cells compared to parent cells. The expression of stemness markers, Oct3/4 and Sox2, increased in the SP-cell-injected tumors. These findings suggested that CSC-like SP cells expressing alpha2-, alpha5-, beta3-, and beta5-integrin, and CD44, may play an important role for peritoneal metastasis in gastric carcinoma. Oct3/4 and Sox2 may be associated with CSC in gastric cancer.

DNA methyltransferase inhibitor 5-aza-CdR enhances the radiosensitivity of gastric cancer cells

The National Comprehensive Cancer Network guidelines recommend radiotherapy as a standard treatment for patients with a high risk of recurrence in gastric cancer. Because radiation is harmful to the surrounding organs, a radiation sensitizer might therefore be useful to decrease the side effects of patients with advanced gastric carcinoma. The aim of the current study was to clarify the effect of a DNA methyltransferase inhibitor, 5-aza-2'-deoxycytidine (CdR), on radiation sensitivity in gastric cancer cells. Five gastric cancer cell lines, OCUM-2M, OCUM-12, KATO-III, MKN-45, and MKN-74, were used. The effects of 5-aza-CdR with irradiation on the growth activity, cell-cycle distribution, apoptosis, and apoptosis-associated gene expression were examined. 5-aza-CdR sensitized three of five gastric cancer cell lines to radiation. A combination of irradiation and 5-aza-CdR significantly (P<0.05) decreased the growth activity compared with irradiation alone in OCUM-2M, OCUM-12, and MKN-45 cells, but not in KATO-III and MKN-74 cells. The percentage of cells in G2-M phase and the apoptotic rate with irradiation in combination with 5-aza-CdR were increased in OCUM-2M, OCUM-12, and MKN-45 cells compared with irradiation alone, but not in KATO-III and MKN-74 cells. 5-aza-CdR increased the expression of p53, RASSF1, and death-associated protein kinases (DAPK) genes compared with the control or irradiation alone. These findings suggest that 5-aza-CdR might therefore be useful as a radiation sensitizer to treat some types of gastric carcinoma. The arrest at G2-M phase and increased apoptotic rate might be partly mediated by enhanced expression of the p53, RASSF1, or DAPK gene families by 5-aza-CdR.

A novel transforming growth factor beta receptor kinase inhibitor, A-77, prevents the peritoneal dissemination of scirrhous gastric carcinoma

PURPOSE

Transforming growth factor beta receptor (TGFbeta-R) is reported to correlate with the malignant potential of scirrhous gastric carcinoma. The aim of the current study is to clarify the possibility of molecular target therapy with a TGFbeta-R inhibitor, A-77, for the treatment of peritoneal dissemination of scirrhous gastric cancer.

EXPERIMENTAL DESIGN

Three scirrhous gastric cancer cell lines and two fibroblasts were used. For in vivo experiments, the A-77 was administered i.p. to mouse models of peritoneal dissemination. The influences of A-77 on the adhesion ability, invasion ability, and the expression of adhesion molecules were examined in vitro.

RESULTS

The A-77 administration resulted in a significantly (P < 0.01) better prognosis for the mice with peritoneal dissemination (median survival time, 51 days), compared with the control (median survival time, 25 days). A-77 therefore significantly (P < 0.01) decreased the weight and number of metastatic nodes. The adhesive ability and invasion ability of cancer cells were significantly decreased by A-77. A-77 decreased the expression of alpha(2), alpha(3), and alpha(5) integrins in gastric cancer cells. The histologic findings showed the degree of fibrosis to be less in the tumors treated by A-77. A-77 decreased the growth of fibroblast and invasion-stimulating activity of fibroblasts on cancer cells.

CONCLUSION

The TGFbeta-R inhibitor, A-77, decreased the expression of integrins in cancer cells and the proliferation of fibroblasts, which resulted in the decreased adhesive and invasive abilities of scirrhous gastric cancer cells to peritoneum. A-77 is thus considered to be useful for the inhibition of peritoneal dissemination of scirrhous gastric carcinoma.

[Efficacy of m-FOLFOX6 therapy for colorectal cancer in elderly patients]

Combination chemotherapy of oxaliplatin, fluorouracil/leucovorin (FOLFOX) has reportedly become a standard regimen for colorectal cancer. In this study, we investigated the efficacies and adverse effects of modified FOLFOX6 (m-FOLFOX6) regimen in elderly patients. Thirty-nine patients with colorectal cancer, who received m-FOLFOX6 in our institution, were studied. Ten of the 39 patients, were older than 70 (elderly patients). Efficacies and adverse effects of m-FOLFOX6 were compared between patients over 70 years of age and those younger than 69 (younger patients). In terms of the response rate, there were no differences between the older and younger elderly patients. Moreover, the grade and frequency of adverse events were similar between them. We concluded that m-FOLFOX6 may bring about the same response rate in older and younger elderly patients. Moreover, m-FOLFOX6 may be given safely regardless of patient age.

Selective cyclooxygenase-2 inhibitor downregulates the paracrine epithelial-mesenchymal interactions of growth in scirrhous gastric carcinoma

The importance of cancer-mesenchymal interactions in the aggressive behavior of scirrhous gastric cancer is supported by experimental and clinical evidences. We have previously reported that gastric fibroblasts secretion of keratinocyte growth factor (KGF) underline the remarkable proliferation of scirrhous gastric cancer cells. Cyclooxygenase-2 (COX-2) is not only expressed in cancer cells, but also in interstitial fibroblasts in gastric carcinoma. To clarify the mechanisms responsible for the antiproliferation effect of COX-2 inhibitors, effect of COX-2 inhibitor on the paracrine epithelial-mesenchymal interactions of growth was examined. Scirrhous gastric cancer cell line, OCUM-2M, gastric fibroblasts, NF-21, and COX-2 inhibitor, JTE-522, were used. Growth-interaction was examined by calculating the number of cancer cells or by measuring [(3)H] thymidine incorporation of cancer cells. Effect of JTE-522 on KGF expression from NF-21 cells and OCUM-2M cells was analyzed by ELISA and RT-PCR. The conditioned medium from gastric fibroblasts significantly stimulated the growth of scirrhous gastric cancer cells. JTE-522 at the concentrations of 10(-5) and 10(-6) M significantly decreased the growth-stimulating activity of gastric fibroblasts. JTE-522 reduced the expression of KGF mRNA and the production of KGF from gastric fibroblasts. Oral administration of JTE-522 significantly decreased the size of xenografted tumor coinoculated with OCUM-2M cells and NF-21 cells in nude mice. JTE-522 decreased COX-2 expression and Ki67 labeling index within the coinoculated tumor. These findings suggested that a selective COX-2 inhibitor, JTE-522, downregulates KGF production from gastric fibroblasts, resulting in the inhibition of paracrine epithelial-mesenchymal interactions of proliferation between scirrhous gastric cancer cells and gastric fibroblasts.

Primary leiomyosarcoma of the breast: report of a case

We describe herein a case of primary leiomyosarcoma of the breast in a 59-year-old woman. Preoperative clinical examination and cytology findings indicated a benign breast tumor, but intraoperative histopathological examination of the tumor revealed malignant spindle cells, and a modified radical mastectomy was performed. Immunohistochemical analysis subsequently confirmed a diagnosis of leiomyosarcoma. Primary leiomyosarcoma of the breast is extremely rare and difficult to diagnose before surgery because of the need for mitotic figures and immunohistochemical staining to confirm the diagnosis. When pre- and intraoperative examinations indicate the possibility of a leiomyosarcoma, an extended excision with sufficient margins should be performed to remove all of the affected tissue. A review of the literature on this unusual tumor of the breast is presented.