Diffuse-type gastric cancer cells switch their driver pathways from FGFR2 signaling to SDF1/CXCR4 axis in hypoxic tumor microenvironments

Cancer-associated fibroblasts (CAFs) have been considered to play an important role for tumor progression of cancer. Solid tumors contain heterogeneous distribution of oxygen in their microenvironments. This study investigated the growth signaling of gastric cancer (GC) cells in focus on the interaction with CAFs and GC cells under normoxia and hypoxia. Four diffuse-type GC cell lines, two intestinal-type GC cell lines and three CAF cell lines were used. Cells were examined for expression of C-X-C chemokine receptor 4 (CXCR4), fibroblast growth factor receptor 2 (FGFR2) and stromal-derived factor 1 (SDF1) by RT-PCR, western blot, ELISA and immunohistochemical staining of xenografted tumors. GC cell proliferation was examined under hypoxia in the presence or absence of CAFs, a FGFR2 inhibitor, a CXCR4 inhibitor and HIF1α siRNA. Proliferation of diffuse-type GC cells, but not intestinal-type GC cells, was significantly increased by CAFs. CXCR4 expression by diffuse-type GC cells was significantly increased in hypoxia, while FGFR2 expression was decreased. CXCR4 expression was correlated with hypoxic microenvironment of xenografted tumor, but FGFR2 expression was not. FGFR2 inhibition significantly decreased the growth-stimulating activity of CAFs for diffuse-type GC cells in normoxia. In contrast, CXCR4 inhibition significantly decreased the growth-stimulating activity of CAFs in hypoxia. SDF1 production by CAFs was increased in hypoxia, while cancer cells did not produce SDF1. HIF1 siRNA significantly decreased both CXCR4 expression by diffuse-type GC cells and SDF1 production by CAFs. These findings suggest that diffuse-type GC cells might switch their driver pathways from FGFR2 signaling to SDF1/CXCR4 axis through HIF1 in hypoxic tumor microenvironments.

Abstract 436: SDF1α / CXCR4 axis might be associated with growth-interaction between cancer-associated fibroblasts and gastric cancer cells in hypoxic tumor microenvironment

Background: Cancer-associated fibroblasts (CAF) have been suggested to be associated with the progression of gastric cancer cells. Hypoxic region was frequently found in cancer microenvironment of gastric cancer. The aim of our study was to clarify the interaction between CAF and gastric cancer cells under hypoxia. We found that hypoxia up-regulated the growth and interaction between the CAF and gastric cancer cells through SDF1α/CXCR4 dependent mechanism.

Materials and Methods: Six gastric cancer cell lines and three fibroblasts cell lines were used. The expression level of CXCR4 under hypoxia was examined by RT-PCR, Western blot. SDF1 production from CAF under hypoxia wad examined by ELISA. The proliferation of diffuse type gastric cancer cells that were co-culture with CAF was examined under hypoxia, in comparison with that under normoxia. Proliferation activity of diffuse type gasitrc cancer cells was examined in the presence of CAF, CXCR4 inhibitor, FGFR2 inhibitor, HIF1α siRNA or CXCR4 siRNA under hypoxia, in comparison with that under normoxia.

Results: The proliferation of diffuse type gastric cancer cells was significantly increased in the presence of CAF. The proliferation - stimulating effects by CAF were evident in hypoxia, in compared with normoxia. CXCR4 expression of diffuse type gastric cancer cells was significantly increased under hypoxia, but decreased FGFR2 expression under hypoxia. HIF1α siRNA significantly down-regulated CXCR4 expression level in hypoxia. SDF1 from CAF was increased under hypoxia, and was also decreased by HIF1α knockdown. FGFR2 inhibitor significantly decreased he proliferation-stimulating activity of CAF under normoxia, but not under hypoxia. Although, CXCR4 inhibitor significantly decreased the proliferation-stimulating activity of CAF under hypoxia, but not under normoxia. These findings suggested that the key signaling associated with the growth-interaction between CAF and gastric cancer cells in hypoxic condition might be different from those in normoxic condition.

Conclusion: Hypoxic microenvironment switch the driver signaling from FGF7/FGFR2 to SDF-1/CXCR4 in diffuse type of gastric cancer. CXCR4/SDF1 axis might play an important role for the proliferation of gastric cancer in hypoxic tumor microenvironment.

Citation Format: Haruhito Kinoshita, Masakazu Yashiro, Hiroaki Kasashima, Go Masuda, Tamami Morisaki, Tatsunari Fukuoka, Katsunobu Sakurai, Takahiro Toyokawa, Kenjiro Kimura, Naoshi Kubo, Hiroaki Tanaka, Kazuya Muguruma, Masaichi Ohira, Kosei Hirakawa. SDF1α / CXCR4 axis might be associated with growth-interaction between cancer-associated fibroblasts and gastric cancer cells in hypoxic tumor microenvironment. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 436. doi:10.1158/1538-7445.AM2015-436

Abstract 992: Significance of an autophagy protein, microtubule-associated protein light chain 3 (LC3), in gastric cancer

Background: Autophagy is an intracellular degradation system that is induced under starvation or hypoxia. Recently, autophagy has been reported to be associated with carcinogenesis and tumor progression. The significance of autophagy in gastric cancer progression remains controversial. Microtubule-associated protein light chain 3 (LC3) is a component of autophagosomes that stimulate autophagy. There are 3 types of LC3 gene family members, LC3A, LC3B and LC3C. LC3A and LC3B were recently reported to be associated with autophagy in LC3 members. The aim of this study was to evaluate the significance of an autophagy protein, LC3, in gastric cancer.

Materials and Methods: A diffuse-type gastric cancer cell line, OCUM-2MD3, was used in this study. Effect of starvation on the expression level of LC3A and LC3B mRNA of OCUM-2MD3 cells was examined by RT-PCR under glucose free condition. A total of 528 patients who underwent resection of a primary gastric cancer were enrolled. The correlation between the clinicopathological features of 528 primary gastric carcinomas and LC3 expression was examined by immunohistochemistry.

Results: Expression level of LC3A and LC3B mRNA significantly increased five and two times respectively in OCUM-2MD3 under glucose free conditions compared to that under high glucose conditions. Immunohistochemical study showed that LC3 expression was positive in 94 (17.8%) of 528 gastric cancers. There was a statistically significant correlation between LC3 positive-expression and histologic type (p = 0.002), lymphatic invasion (p<0.001), venous invasion (p<0.001), and hepatic metastasis (p = 0.033). The Kaplan-Meier survival curve showed that LC3 expression was significantly associated with poor overall survival (p<0.001). Univariate analysis showed that LC3 expression was associated with poor prognosis in gastric cancer patients (p = 0.040), while multivariate analysis found that LC3 expression was not statistically significant (p = 0.255).

Conclusion: LC3 might play an important role for autophagy of gastric cancer cells in starvation condition. LC3 is associated with progression of gastric cancer, and is a useful prognostic marker for patients with gastric cancer.

Citation Format: Go Masuda, Masakazu Yashiro, Hiroaki Kasashima, Haruhito Kinoshita, Tatsunari Fukuoka, Tamami Morisaki, Tsuyoshi Hasegawa, Katsunobu Sakurai, Takahiro Toyokawa, Naoshi Kubo, Hiroaki Tanaka, Kazuya Muguruma, Masaichi Ohira, Kosei Chung. Significance of an autophagy protein, microtubule-associated protein light chain 3 (LC3), in gastric cancer. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 992. doi:10.1158/1538-7445.AM2015-992

Abstract 4100: Epithelial-mesenchymal transition and tumor vascular remodeling in eribulin chemotherapy for breast cancer

Purpose: Eribulin mesylate (eribulin) is a promising chemotherapeutic agent to treat locally advanced or metastatic breast cancer (MBC). Not only its cytotoxic efficacy, but its unique mechanisms to suppress epithelial-mesenchymal transition (EMT) of the cancer cells, or to promote tumor vascular remodeling attracted attention in basic models. In this study, we investigated markers of EMT and hypoxia in sets of clinical specimens before and after treatment of eribulin in an aim to verify its profound mechanisms.

Experimental Design: A series of 20 sets of the tissue specimens of MBC obtained before and after chemotherapy from patients treated either with eribulin (n = 10), or with paclitaxel (n = 10) were immunohistochemically investigated with the expression of E-cadherin, N-cadherin, Vimentin, and CA9. The cut-off for E-cadherin positivity was >30% positive tumor cells with membrane staining. The cut-off for N-cadherin and Vimentin positivity were >10% positive tumor cells with cytoplasm staining. And, the cut-off for CA9 positivity was >10% positive tumor cells with membrane staining.

Results: Looking at the relation between the transition in this protein expression and therapeutic effect, cases observed with positive conversion in E-cadherin expression and cases observed with negative conversion in CA9 expression had significantly high response rate (RR) (p = 0.004, p = 0.024). Among high RR cases, E-cadherin expression was remarkably increased, the N-cadherin, Vimentin and CA9 expression were reduced. A significant prolongation of progression-free survival (PFS) was observed in patients with tumor showed E-cadherin positive-conversion (p = 0.041, log-rank). Significantly longer periods of time to treatment-failure (TTF) were achieved in patients with tumors showed E-cadherin positive-conversion (p = 0.018, log-rank) or showed CA9 negative-conversion (p = 0.038, log-rank). There was no difference in over-all survival (OS) of the patients when stratified with the expression of and change in EMT markers. No difference was observed either in PFS, TTF, or OS of the patients according to the expressions of and change in N-cadherin and Vimentin.Conclusions: Increased expression of E-cadherin was observed along with reduced expression of N-cadherin, Vimentin, and CA9, EMT suppression was caused by eribulin chemotherapy, and further, it was suggested that vascular remodeling may have been induced.

Citation Format: Kashiwagi Shinichiro, Yuka Asano, Yukie Tauchi, Tokumoto Mao, Tamami Morisaki, Satoru Noda, Hidemi Kawajiri, Tsutomu Takashima, Naoyoshi Onoda, Kosei Hirakawa. Epithelial-mesenchymal transition and tumor vascular remodeling in eribulin chemotherapy for breast cancer. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4100. doi:10.1158/1538-7445.AM2015-4100

Abstract 1824: Predictive value of neutrophil-lymphocyte ratio for the efficacy of preoperative chemotherapy in triple-negative breast cancer

Purpose: Abnormalities in the subpopulations in white blood cells, such as neutrophilia and lymphopenia, have been reported in tumor-bearing patients, and the neutrophil/ lymphocyte ratio (NLR) has been found to associate with prognosis in patients following radical surgery. The NLR was reported to associate with prognosis in cancer patients by influencing both cancer progression and chemosensitivity. The correlation between NLR and the outcome of neoadjuvant chemotherapy (NAC) in breast cancer patients has not been elucidated yet. The aim of this study is to evaluate NLR as one of the possible markers to predict the outcome of NAC in patients with TNBC by a retrospective investigation of the consecutive patient series treated with a standardized single protocol in our institute.

Experimental Design: NLR was evaluated in a total of 177 patients with early-stage breast cancer treated with NAC consisting FEC (5-fluorouracil, epirubicin, and cyclophosphamide) followed by weekly paclitaxel followed by curative surgery. The correlation between NLR and the prognosis including the efficacy of the NAC was evaluated retrospectively. NLR was calculated from the preoperative blood sample by dividing the absolute neutrophil count by the absolute lymphocyte count. On the basis of previous studies, an NLR value of 3.0 was used as the cut-off value to discriminate between high-NLR (3.0 and over) and low-NLR (less than 3.0) groups.

Results: NLR distributed from 0.5 to 10.6 with a median of 2.0. Fifty-eight patients with low NLR (less than 3) had a higher pCR rate (p<0.001), and more frequently diagnosed to have TNBC (p<0.001) compared with those with high NLR (3 and over). Among TNBC patients who achieved pCR, DFS (p = 0.006) and OS (p<0.001) were significantly longer in patients with low NLR than that with high NLR. Low NLR was associated with a significantly favorable prognosis in TNBC patients who achieved pCR, according to univariate analysis (p = 0.044, HR = 0.06).

Conclusions: Low NLR in patients with TNBC could be expected to show high efficacy, and favorable outcome after NAC.

Citation Format: Yuka Asano, Shinichiro Kashiwagi, Tamami Morisaki, Satoru Noda, Hidemi Kawajiri, Tsutomu Takashima, Naoyoshi Onoda, Kosei Hirakawa. Predictive value of neutrophil-lymphocyte ratio for the efficacy of preoperative chemotherapy in triple-negative breast cancer. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 1824. doi:10.1158/1538-7445.AM2015-1824

Abstract 1405: Novel biomarkers for gastric cancer stem cells utilizing comparative proteomics analysis

Purpose: Cancer stem cells (CSCs) are responsible for cancer progression, metastasis, and recurrence. The identification of CSC markers may open a new therapeutic perspective on the basis of selectively targeting this small population of cancer cells, however, the specific markers of CSCs remain undiscovered. The aim of this study was to identify novel biomarkers of gastric CSCs for clinical diagnosis using proteomics technology.

Materials and Methods: Since the side population (SP) cells of gastric cancer possess CSC-like properties, we used CSC-like SP cells, OCUM-12/SP cells and OCUM-2MD3/SP cells in this study. Their parent OCUM-12 cells and OCUM-2MD3 cells were also used. Protein lysates from each cell line were analyzed using QSTAR Elite Liquid Chromatography with Tandem Mass Spectrometry, coupled with isobaric tags for relative and absolute quantitation technology. Proteins overexpressed in SP cells were determined by comparing the proteomes among parent cells and CSC-like SP cells. Candidate proteins detected by proteomics technology were validated by RT-PCR, western blot, invasion assay, and immunohistochemical analysis of 300 gastric cancers.

Results: Based on the results of LC-MS/MS, eight proteins, including RBBP6, GLG1, VPS13A, DCTPP1, HSPA9, HSPA4, ALDOA, and KRT18, were up-regulated in both OCUM-12/SP cells and OCUM-2MD3/SP cells when compared to their corresponding parent cells. RT-PCR analysis indicated that the expression level of RBBP6, HSPA4, DCTPP1, HSPA9, VPS13A, ALDOA, GLG1, and CK18 was high in OCUM-12/SP and OCUM-2MD3/SP, in compared with the control of parent OCUM-12 and OCUM-2MD3. These proteins were significantly associated with advanced invasion depth, lymph node metastasis, distant metastasis, or advanced clinical stage. RBBP6, DCTPP1, HSPA4, and ALDOA expression in particular were significantly associated with a poor prognosis in the 300 gastric cancer patients. RBBP6 was determined to be an independent prognostic factor. The motility-stimulating ability of OCUM-12/SP cells and OCUM-2MD3/SP cells was inhibited by RBBP6 siRNA.

Conclusion: The eight proteins, RBBP6, GLG1, VPS13A, DCTPP1, HSPA9, HSPA4, ALDOA, and KRT18, utilizing comparative proteomics analysis, were perceived to be potential CSC markers of gastric cancer. Of the eight candidate proteins, RBBP6 was suggested to be a promising prognostic biomarker and a therapeutic target for gastric cancer.

Citation Format: Masakazu Yashiro, Tamami Morisaki, Tsuyoshi Hasegawa, Anna Kakehashi, Haruhito Kinoshita, Tatsunari Fukuoka, Hiroaki Kasashima, Go Masuda, Katsunobu Sakurai, Naoshi Kubo, Hiroaki Tanaka, Kazuya Muguruma, Masaichi Ohira, Hideki Wanibuchi, Kosei Hirakawa. Novel biomarkers for gastric cancer stem cells utilizing comparative proteomics analysis. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 1405. doi:10.1158/1538-7445.AM2015-1405

The significance and the predictive factors of microscopic lymph node metastasis in patients with clinically node negative papillary thyroid cancer: A retrospective cohort study

BACKGROUND

The management of pathological lateral node involvement (pN1b) from papillary thyroid cancer (PTC) are controversial.

METHODS

A consecutive series of 246 patients, diagnosed with clinically node negative (cN0) PTC who had undergone surgery with prophylactic lateral node dissection, and without postoperative radioactive iodine administration from 2001 to 11, were reviewed to clarify the significance of pN1b.

RESULTS

Eighty-five (35%) patients had pN1b disease. One-half and 30% had pN1b in younger (age less than 45) and older patients (age 45 or over), respectively. Tumor size (≥ 21 mm) could predict pN1b disease in older patients. Patients with pN1b disease recurred more frequently (9 cases, 10.6%) than those without (4 cases, 2.4%), and 2 cases with pN1b died of the disease.

CONCLUSIONS

pN1b disease was commonly found in patients with PTC even when they were diagnosed clinically as node negative. pN1b disease with prognostic meaning was often found in the older patients with larger PTC indicating the necessity for adjuvant treatments.

Comparative proteomics analysis of gastric cancer stem cells

Cancer stem cells (CSCs) are responsible for cancer progression, metastasis, and recurrence. To date, the specific markers of CSCs remain undiscovered. The aim of this study was to identify novel biomarkers of gastric CSCs for clinical diagnosis using proteomics technology. CSC-like SP cells, OCUM-12/SP cells, OCUM-2MD3/SP cells, and their parent OCUM-12 cells and OCUM-2MD3 cells were used in this study. Protein lysates from each cell line were analyzed using QSTAR Elite Liquid Chromatography with Tandem Mass Spectrometry, coupled with isobaric tags for relative and absolute quantitation technology. Candidate proteins detected by proteomics technology were validated by immunohistochemical analysis of 300 gastric cancers. Based on the results of LC-MS/MS, eight proteins, including RBBP6, GLG1, VPS13A, DCTPP1, HSPA9, HSPA4, ALDOA, and KRT18, were up-regulated in both OCUM-12/SP cells and OCUM-2MD3/SP cells when compared to their corresponding parent cells. RT-PCR analysis indicated that the expression level of RBBP6, HSPA4, DCTPP1, HSPA9, VPS13A, ALDOA, GLG1, and CK18 was high in OCUM-12/SP and OCUM-2MD3/SP, in compared with the control of parent OCUM-12 and OCUM-2MD3. These proteins were significantly associated with advanced invasion depth, lymph node metastasis, distant metastasis, or advanced clinical stage. RBBP6, DCTPP1, HSPA4, and ALDOA expression in particular were significantly associated with a poor prognosis in the 300 gastric cancer patients. RBBP6 was determined to be an independent prognostic factor. The motility-stimulating ability of OCUM-12/SP cells and OCUM-2MD3/SP cells was inhibited by RBBP6 siRNA. These findings might suggest that the eight proteins, RBBP6, GLG1, VPS13A, DCTPP1, HSPA9, HSPA4, ALDOA, and KRT18, utilizing comparative proteomics analysis, were perceived to be potential CSC markers of gastric cancer. Of the eight candidate proteins, RBBP6 was suggested to be a promising prognostic biomarker and a therapeutic target for gastric cancer.

[A case of squamous cell lung carcinoma that was difficult to distinguish from squamous cell carcinoma of the breast]

A 74 -year-old man was hospitalized for chest pain. Chest computed tomography showed a 4 × 8 cm-sized tumor pressing on the left pectoralis major muscle. Subsequent imaging showed progression of the tumor along with rib erosion and intrapleural invasion. The patient was admitted to our hospital for a follow-up examination of the tumor. Bronchoscopy results were normal. Ultrasound-guided percutaneous needle biopsy was performed. Histopathology indicated squamous cell carcinoma on the basis of the presence of keratin pearls. We therefore diagnosed the patient with squamous cell lung carcinoma fStage IIb (T3N0M0) and subsequently administered chemoradiotherapy owing to the inoperable status of the lesion. We report a case of squamous cell lung carcinoma that was difficult to differentiate from squamous cell carcinoma of the breast, along with a review of the literature.

[Four cases of malignant primary breast lymphoma]

Primary malignant lymphoma of the breast (PBL) is comparatively rare in Japan.Herein, the authors present report 4 cases of PBL. All patients had the primary finding of a palpable left breast mass.Malignant lymphoma was strongly suspected by core needle biopsy, and final diagnosis was made on surgical specimens. All cases were diffuse large B-cell lymphoma and were treated with targeted chemotherapy with R-CHOP. Only 1 of the 4 patients needed multidisciplinary therapy due to advanced age.Whenever PBL is suspected, targeted therapy should be considered.

[Clinical experience with a handheld vacuum-assisted biopsy system (VACORA® )for mammary lesions]

We evaluated the usefulness and safety of a handheld vacuum-assisted biopsy system (VACORA®) in 253 lesions suspected to be malignant. Biopsy samples were successfully obtained from 252 lesions, and no complications occurred that required other treatments during or after the biopsy. The definitive diagnosis rate using VACORA / ®was 89.3% (226/253). For 27 lesions, biopsy using Mammotome®or open biopsy was performed because a diagnosis could not be made with the VACORA® system, despite a category 4 result on ultrasonography. The lesions that were diagnosed as benign using the VACORA® system did not manifest malignant features during the observation period (1-36 months). We considered the VACORA® biopsy system as an effective technique that has both convenience and high diagnostic accuracy.

[Eribulin chemotherapy after taxane treatment in advanced metastatic breast cancer]

Clinical outcomes, including adverse events, in 52 advanced breast cancer patients treated with eribulin chemotherapy after taxane treatment (TX) were analyzed to confirm the effectiveness and safety of this treatment.The objective response rate (ORR) in patients was 34.6% (TX group 31.6%, non-TX group 36.4%). There were no significant differences in overall survival, time to treatment failure, or progression-free between three TX and non-TX groups. Further, adverse events did not differ between groups expression of neutropenia of Grade 3 or more. On the other hand, the number of patients with sensory peripheral neuropathy of Grade 1 or more was significantly more in the TX group than in the non-TX group. Eribulin chemotherapy was effective for the treatment of advanced breast cancer regardless of a history of taxane treatment.In addition, sensory peripheral neuropathy is a possible complication that can occur in advanced breast cancer patients treated with eribulin chemotherapy with taxane treatment history.

[Clinical experience of nab-Paclitaxel treatment in 31 patients with breast cancer]

Nanoparticle albumin-bound paclitaxel (nab-PTX, Abraxane®) does not require premedication, and it can be used for patients with alcohol intolerance. We administered nab-PTX to 31 patients with breast cancer between October 2010 and April 2013. Eighteen patients had progressive, recurring breast cancers and 13 patients had locally advanced operable breast cancers. The treatment schedules were 175 or 260 mg/m² every 3 weeks (q3w). No patient experienced an allergic reaction. Grade 1-3 sensory neuropathies were observed in 20 patients; however, no patient experienced grade 4 neuropathy. In patients with locally advanced, operable breast cancer, 1 patient treated with 175 mg/m² q3w had a partial response (PR), while of the patients treated with 260 mg/m² q3w, 10 patients showed a PR, and 1 patient had stable disease (SD). Of the patients with progressive, recurring breast cancer, 2 patients showed a PR and 4 patients had SD when treated with 175 mg/m² q3w, whereas 1 patient displayed a PR and 1 patient had SD when treated with 260 mg/m² q3w. Our investigation suggests that nab-PTX is well tolerated, even by patients with advanced breast cancer.

High-impedance wire grid method to study spatiotemporal behavior of hot electron clump generated in a plasma

High-impedance Wire Grid (HIWG) detector has been developed to study spatiotemporal behavior of a hot electron clump generated in an electron cyclotron resonance (ECR) plasma. By measuring the floating potentials of the wire electrodes, and generating structure matrix made of geometrical means of the floating potentials, the HIWG detector reconstructs the spatial distribution of high-temperature electron clump at an arbitrary instant of time. Time slices of the spike event in floating potential revealed the growth and decay process of a hot spot occurs in an ECR plasma.

Abstract 3606: The effect of PGE2 receptor inhibitor on the microenviroment of scirrhous gastric cancer

Introduction: Prostaglandins and cyclooxygenase2 have been suggested to play an important role for the proliferation and migration of cancer cells. But Prostaglandins (PG) have been suggested to affect cancer cells in various directions. For example, PGF2α and PGD2 has been demonstrated to have anti-tumor effects against some types of cancer cells. But PGE2 has been demonstrated to promote the proliferation and migration of cancer. Therefore, the investigation of the involvement of PG signals for cancer in lower level of arachidonic acid cascade is very important. The aim of this study is to investigate the effects of PGE2 and PGE2 receptor inhibitor (EP2 inhibitor) on the growth-interaction between cancer cells and fibroblasts.

Methods: Three human gastric cancer cell lines (OCUM-2M, OCUM-2MD3, OCUM-12) and a human gastric fibroblast (CAF45) cell line were used in this study. Serum-free conditioned medium (SF-CM) from CAF-45 stimulated with PGE2 or EP2 inhibitor was prepared and used in study. Cell proliferation was studied by MTT assay and cell count in the presence or absence of CAF45. Cell migration was studied by wound healing assay in the presense or absence of SF-CM. In vivo study, We examined the effect of EP2 inhibitor on subcutaneous and orthotopically transplanted tumors.

Results: In proliferation, PGE2 significantly stimulated the proliferation and migration of cancer cells. PGE2 significantly stimulated the proliferation and migration of cancer cells co-cultured with CAF45 or SF-CM more in comparison with single culture. EP2 inhibitor significantly decreased the proliferation and migration of cancer cells, EP2 inhibitor significantly decreased the proliferation migration of cancer cells co-cultured with CAF-45 or SF-CM more in comparison with single culture. In vivo study, EP2 inhibitor significantly suppressed the subcutaneous tumor in nude mice and suppressed orthotopic tumor growth and lymph node metastasis.

Conclusion: PGE2 is associated with progression of gastric cancer. PGE2 receptor inhibitors might be promising anti-cancer drug for gastric carcinoma.

Citation Format: Tatsunari Fukuoka, Masakazu Yashiro, Hiroshi Takeda, Takayuki Maruyama, Hiroaki Kasashima, Go Masuda, Haruhito Kinoshita, Tamami Morisaki, Katsunobu Sakurai, Masatsune Shibutani, Sadaaki Yamazoe, Kenjiro Kimura, Hisashi Nagahara, Takahiro Toyokawa, Ryosuke Amano, Naoshi Kubo, Hiroaki Tanaka, Kazuya Muguruma, Hiroshi Otani, Kiyoshi Maeda, Masaichi Ohira, Kosei Hirakawa. The effect of PGE2 receptor inhibitor on the microenviroment of scirrhous gastric cancer. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 3606. doi:10.1158/1538-7445.AM2014-3606

Abstract 1980: Role of lysyl oxidase and lysyl oxidase-like 2 in gastric carcinoma

Object: Lysyl oxidase (LOX) family is the extracellular matrix-modifying enzymes comprising of LOX and LOX-like (LOXL) 1-4. These enzymes have intracellular functions involved in the regulation of motility, migration, differentiation, and transcription in various types of cells. LOX is associated with mesenchymal reconstruction that is essential for cancer invasion and metastasis. LOX overexpression is crucial to promoting tumor growth and metastasis in several cancers such as breast cancer and colorectal cancer, however, role of LOX in gastric cancer remain unknown. Here, we investigated the clinicopathological significance of LOX and LOXL2 in gastric cancer.

Materials and Methods: A total of 549 patients who had undergone surgery for gastric cancer at Osaka-City University were enrolled. LOX and LOXL2 expressions were evaluated by intensity of staining and percentage of stained tumor cells at the invading tumor front. This study was approved by the Osaka City University ethics committee. Informed consent was obtained from all patients.

Results: LOX and LOXL2 expression were positive in 265 (48.3%) and 342 (58.5%) of the 549 gastric tumors. Both LOX and LOXL2 expression in cancer cells were significantly associated with macroscopic type (p<0.01), histological type (p<0.01), depth of invasion (p<0.01), lymph node status (p<0.01), vessel invasion (p<0.01). The prognosis of patients with LOX-positive tumors or LOXL2-positive tumors was significantly (p<0.001 or p<0.001, log-rank) worse than that of patients with LOX-negative or LOXL2-negative tumors, respectively. A multivariate analysis indicated LOX and LOXL2 expression in cancer cells to be an independent prognostic factor (p=0.016 or p<0.001).

Conclusions: LOX and LOXL2 expression might be associated with metastatic activity of gastric cancer cells. LOX and LOXL2 might be useful predictive prognostic factors for patients with gastric cancer.

Citation Format: Hiroaki Kasashima, Masakazu Yashiro, Yukie Go, Go Masuda, Haruhito Kinoshita, Mao Tokumoto, Tamami Morisaki, Tatsunari Fukuoka, Takahiro Toyokawa, Naoshi Kubo, Hiroaki Tanaka, Kazuya Muguruma, Masaichi Ohira, Kosei Hirakawa. Role of lysyl oxidase and lysyl oxidase-like 2 in gastric carcinoma. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 1980. doi:10.1158/1538-7445.AM2014-1980

Abstract 3612: Effect of cancer associated fibroblast on gastric cancer cells under hypoxia

Background:

Cancer-associated fibroblasts (CAF) have been suggested to be associated with the scirrhous gastric cancer (SGC) progression. SGC have a heterogeneously hypoxic environment which has been currently considered to be associated with aggressive tumor phenotypes cancer. Stromal cell-derived factor (SDF)-1 and C-X-C chemokine receptor type 4 (CXCR4) form an important chemokine/receptor pair, and are supposed to be up-regulated by hypoxia inducible factor-1 (HIF-1). The aim of our study was to clarify the effect of hypoxic environment on the CAF and CXCR4/SDF-1 axis in SGC.

Experimental Design:

Proliferation of SGC cells grown in monoculture and co-culture with CAF under hypoxia. SGC and CAF expression level of CXCR4 and SDF-1 under hypoxia were examined by RT-PCR and ELISA. Proliferation and migration of SGC cells with SDF-1 or hepatocyte growth factor (HGF) or conditioned medium from CAF under hypoxia, furthermore, added c-Met inhibitor or CXCR4 inhibitor.

Results:

The proliferation that co-culture of SGC cells with CAF was significantly increased under hypoxia. The expression level of CXCR4 mRNA was significantly increased under hypoxia in all of SGC cells. SDF-1 concentration level was significantly increased under hypoxia. The proliferation of SGC cells with SDF-1 and CAF was significantly increased. The proliferation of SGC cells with CAF was inhibited by CXCR4 inhibitor under hypoxia. The migration of SGC cells with HGF and CAF was significantly increased. The migration of SGC cells with CAF was inhibited by c-Met inhibitor.

Conclusion:

CAF might up-regulate the proliferation and migration of SGC cells under hypoxia, in comparison with that under normoxia. CXCR4/SDF-1 axis might play an important role for the proliferation of SGC cells under hypoxia.

Citation Format: Haruhito Kinoshita, Masakazu Yashiro, Go Masuda, Hiroaki Kasashima, Tamami Morisaki, Tatsunari Fukuoka, Masatune Shibutani, Sadaaki Yamazoe, Katsunobu Sakurai, Hisashi Nagahara, Kenjiro Kimura, Takahiro Toyokawa, Ryosuke Amano, Naoshi Kubo, Hiroaki Tanaka, Kazuya Muguruma, Hiroshi Otani, Kiyoshi Maeda, Masaichi Ohira, Kosei Hirakawa. Effect of cancer associated fibroblast on gastric cancer cells under hypoxia. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 3612. doi:10.1158/1538-7445.AM2014-3612

Compact and high-particle-flux thermal-lithium-beam probe system for measurement of two-dimensional electron density profile

A compact and high-particle-flux thermal-lithium-beam source for two-dimensional measurement of electron density profiles has been developed. The thermal-lithium-beam oven is heated by a carbon heater. In this system, the maximum particle flux of the thermal lithium beam was ~4 × 10(19) m(-2) s(-1) when the temperature of the thermal-lithium-beam oven was 900 K. The electron density profile was evaluated in the small tokamak device HYBTOK-II. The electron density profile was reconstructed using the thermal-lithium-beam probe data and this profile was consistent with the electron density profile measured with a Langmuir electrostatic probe. We confirm that the developed thermal-lithium-beam probe can be used to measure the two-dimensional electron density profile with high time and spatial resolutions.