[A Case of Advanced Gastric Cancer with Peritoneal Dissemination after Gastrectomy Successfully Treated with Paclitaxel plus Ramucirumab].

In the latest Japanese gastric cancer treatment guidelines, paclitaxel(PTX)plus ramucirumab(RAM)was positioned as a second-line chemotherapy for advanced gastric cancer. We report a case of advanced gastric cancer with peritoneal dissemination after gastrectomy successfully treated with PTX plus RAM. A 68-year-old man underwent distal gastrectomy with D2 lymph node dissection. The pathological diagnosis was moderately differentiated tubular adenocarcinoma, pT4apN1 M0, CY0, Stage ⅢA. He was treated with postoperative adjuvant chemotherapy of S-1. Four months after surgery, peritoneal dissemination was observed, he received capecitabine plus oxaliplatin therapy. However, 5 months after surgery, peritoneal dissemination became progressive disease and PTX plus RAM commenced. During the course of treatment, proteinuria (Grade 2), lower limb edema(Grade 2)and neutropenia(Grade 4)were observed as adverse events, but continuation of this chemotherapy was feasible. The patient survived without progression for 18 months after the recurrence was detected.

Development of a Tissue-Engineered Artificial Ligament: Reconstruction of Injured Rabbit Medial Collateral Ligament With Elastin-Collagen and Ligament Cell Composite Artificial Ligament.

Ligament reconstruction using a tissue-engineered artificial ligament (TEAL) requires regeneration of the ligament-bone junction such that fixation devices such as screws and end buttons do not have to be used. The objective of this study was to develop a TEAL consisting of elastin-coated polydioxanone (PDS) sutures covered with elastin and collagen fibers preseeded with ligament cells. In a pilot study, a ring-type PDS suture with a 2.5 mm (width) bone insertion was constructed with/without elastin coating (Ela-coat and Non-coat) and implanted into two bone tunnels, diameter 2.4 mm, in the rabbit tibia (6 cases each) to access the effect of elastin on the bond strength. PDS specimens taken together with the tibia at 6 weeks after implantation indicated growth of bone-like hard tissues around bone tunnels accompanied with narrowing of the tunnels in the Ela-coat group and not in the Non-coat group. The drawout load of the Ela-coat group was significantly higher (28.0 ± 15.1 N, n = 4) than that of the Non-coat group (7.6 ± 4.6 N, n = 5). These data can improve the mechanical bulk property of TEAL through extracellular matrix formation. To achieve this TEAL model, 4.5 × 106 ligament cells were seeded on elastin and collagen fibers (2.5 cm × 2.5 cm × 80 µm) prior to coil formation around the elastin-coated PDS core sutures having ball-shape ends with a diameter of 2.5 mm. Cell-seeded and cell-free TEALs were implanted across the femur and the tibia through bone tunnels with a diameter of 2.4 mm (6 cases each). There was no incidence of TEAL being pulled in 6 weeks. Regardless of the remarkable degradation of PDS observed in the cell-seeded group, both the elastic modulus and breaking load of the cell-seeded group (n = 3) were comparable to those of the sham-operation group (n = 8) (elastic modulus: 15.4 ± 1.3 MPa and 18.5 ± 5.7 MPa; breaking load: 73.0 ± 23.4 N and 104.8 ± 21.8 N, respectively) and higher than those of the cell-free group (n = 5) (elastic modulus: 5.7 ± 3.6 MPa; breaking load: 48.1 ± 11.3 N) accompanied with narrowed bone tunnels and cartilage matrix formation. These data suggest that elastin increased the bond strength of TEAL and bone. Furthermore, our newly developed TEAL from elastin, collagen, and ligament cells maintained the strength of the TEAL even if PDS was degraded.

Peritoneal Dialysis Fluid-Induced Fragmentation of Golgi Apparatus as a Biocompatibility Marker.

In vitro biocompatibility assessments that consider physiologically appropriate conditions of cell exposure to peritoneal dialysis fluids (PDFs) are still awaited. In this study, we found that fragmentation of Golgi apparatus occurred in a pH-dependent manner within 30-min exposure to five distinct commercially available PDFs, which showed no marked difference in their effects on cell viability in the conventional MTT assay. Fluorescence microscopy analysis of labeling antibody against cis-Golgi protein GM130 indicated that the stacked cisternal structure was maintained in the perinuclear area of both M199 culture medium and a neutral-pH PDF groups. However, this specific structure became partially disassembled over time even in a neutral-pH PDF, and fragmentation was markedly enhanced in cells exposed to neutralized-pH PDFs in correspondence with their intracellular pH; moreover, in acidic PDFs, Golgi staining was diffuse and scattered in the entire cytoplasm and showed partial aggregation. The Golgi fragmentation markedly observed with the neutralized PDFs could be reversed by replacing either the media with a neutral-pH medium or a mixture of PDF and PD effluent (PDF) in a gradient manner mimicking clinical conditions. Furthermore, although weaker than pH effect, notable effects of other PDF-related factors were also observed after 30-min exposure to pH-adjusted PDFs. Lastly, the results of studies conducted using MAPK/SAPK inhibitors indicated that the mechanism underlying the Golgi fragmentation described here differs from that associated with the fragmentation that occurs at the G2/M checkpoint in the cell cycle. We conclude that Golgi fragmentation is suitable for rapid biocompatibility assessment of PDF not only because of its strong pH dependence but also because the fragmentation is recognizably affected by PDF constituents.

Development of Tissue-Engineered Ligaments: Elastin Promotes Regeneration of the Rabbit Medial Collateral Ligament.

When ligaments are injured, reconstructive surgery is sometimes required to restore function. Methods of reconstructive surgery include transplantation of an artificial ligament and autotransplantation of a tendon. However, these methods have limitations related to the strength of the bone-ligament insertion and biocompatibility of the transplanted tissue after surgery. Therefore, it is necessary to develop new reconstruction methods and pursue the development of artificial ligaments. Elastin is a major component of elastic fibers and ligaments. However, the role of elastin in ligament regeneration has not been described. Here, we developed a rabbit model of a medial collateral ligament (MCL) rupture and treated animal knees with exogenous elastin [100 µg/(0.5 mL·week)] for 6 or 12 weeks. Elastin treatment increased gene expression and protein content of collagen and elastin (gene expression, 6-fold and 42-fold, respectively; protein content, 1.6-fold and 1.9-fold, respectively), and also increased the elastic modulus of MCL increased with elastin treatment (2-fold) compared with the controls. Our data suggest that elastin is involved in the regeneration of damaged ligaments.

Newly Developed Neutralized pH Icodextrin Dialysis Fluid: Nonclinical Evaluation.

A two-compartment system (NICOPELIQ; NICO, Terumo Co., Tokyo, Japan) has recently been developed to neutralize icodextrin peritoneal dialysis fluid (PDF). In this study, a nonclinical evaluation of NICO was carried out to evaluate biocompatibility as well as water transport ability. Glucose degradation products (GDPs) in the icodextrin PDFs were analyzed via high-performance liquid chromatography (HPLC). The cell viability of human peritoneal mesothelial cells derived from peritoneal dialysis effluent (PDE-HPMCs) was evaluated as well as the amount of lactate dehydrogenase (LDH) released after exposure to different PDFs (NICO and EXTRANEAL [EX, Baxter Healthcare Corp., Chicago, IL, USA]) and neutralized pH glucose PDF MIDPELIQ 250 (M250, Terumo). The water transport ability of NICO, EX, and M250 was tested using dialysis tube membranes with various pore sizes: 1, 2, 6-8, and 12-16 kDa. Although cell viability decreased by 30% after 30 min exposure to NICO, it was maintained for 6 h while a significant decrease was observed after 6 h exposure to EX. However, following adjustment of the pH to the same pre-exposure pH value, there was no significant difference in cell viability within the same pH group despite a doubling of the difference in the total amount of GDPs (44.6 ± 8.6 µM in NICO and 91.9 ± 9.5 µM in EX, respectively). In contrast, a significant decrease in cell viability was observed when the pH decreased to less than pH 6. Levels of released LDH, a cytotoxic marker, were within 5% after a 6-h exposure of NICO to PDE-HPMCs. There was no significant difference in water transport ability represented as overall osmotic gradients between NICO and EX. In conclusion, neutralization of icodextrin PDF is beneficial for maintaining cell viability and minimizing LDH release while water transport ability is comparable to the conventional icodextrin PDF.

Aneurysm Organization Effects of Gellan Sulfate Core Platinum Coil with Tenascin-C in a Simulated Clinical Setting and the Possible Mechanism.

BACKGROUND: This study aimed to deliver gellan sulfate core platinum coil with tenascin-C (GSCC-TNC) into rabbit side-wall aneurysms endovascularly and to evaluate the organization effects in a simulated clinical setting. METHODS: Elastase-induced rabbit side-wall aneurysms were randomly coiled via a transfemoral route like clinical settings with platinum coils (PCs), gellan sulfate core platinum coils (GSCCs), or GSCC-TNCs (n = 5, respectively). Aneurysm-occlusion status was evaluated angiographically and histologically at 2 weeks post coiling. As each rabbit coiled aneurysm provided only 2-3 tissue slices due to technical limitations and prevented immunohistochemical evaluations, a PC, GSCC, or GSCC-TNC was randomly implanted in a rat blind-ended model (n = 3, respectively) and the organization effects were immunohistochemically evaluated for expressions of tenascin-C (TNC), transforming growth factor-beta (TGF-ß), and matrix metalloproteinase-9 (MMP-9) 2 weeks later. RESULTS: Coil handling was similar among the 3 kinds of coils. GSCCs showed a significantly higher ratio of organized area to the aneurysmal cavity than PCs, but GSCC-TNCs had the greatest organization-promoting effects on aneurysms (the ratio of organized area/aneurysmal luminal area: PC, 17.9 ± 7.1%; GSCC, 54.2 ± 18.3%; GSCC-TNC, 82.5 ± 5.8%). GSCC-TNCs had intense immunoreactivities for TNC, TGF-ß, and MMP-9 in the organized thrombosis and tunica media. GSCCs also showed intense immunoreactivities for TNC, TGF-ß, and MMP-9, although the extent was less than GSCC-TNCs. The immunoreactivities were hardly found in unorganized thrombus and the tunica media of aneurysm wall in the PC group. CONCLUSIONS: This study first showed that GSCC-TNCs promote intra-aneurysmal clot organization in simulated clinical settings using rabbits possibly through the TGF-ß and MMP-9 upregulation.

Effect of tenascin-C on the repair of full-thickness osteochondral defects of articular cartilage in rabbits.

The purpose of this study was to examine the effect of tenascin-C (TNC) on the repair of full-thickness osteochondral defects of articular cartilage in vivo. We used a gellan-gellan-sulfate sponge (Gellan-GS) to maintain a TNC-rich environment in the cartilage defects. We implanted Gellan-GS soaked in PBS only (Group 1), Gellan-GS soaked in 10 µg/ml of TNC (Group 2), and Gellan-GS soaked in 100 µg/ml of TNC (Group 3) into a full-thickness osteochondral defect of the patellar groove of rabbits. The defect area was examined grossly and histologically 4-12 weeks after surgery. Sections of synovium were also immunohistochemically investigated. Histologically as well as macroscopically, the defects in Group 2 showed better repair than the other groups at 8 and 12 weeks after surgery. Inflammation of the synovium tended to diminish over time in all groups, and the degree of synovitis was the same for all three groups at each time point. In conclusion, Gellan-GS soaked in TNC can be used as a novel scaffold for the repair of articular cartilage defects. This study also indicates that TNC promotes the repair of full-thickness osteochondral defects in vivo.

[A case of syndrome of inappropriate antidiuretic hormone secretion in a patient with esophageal carcinoma possibly induced by cisplatin in neoadjuvant chemotherapy].

A 60 -year-old man complained of dysphagia and was admitted to our hospital for adjuvant chemotherapy under a diagnosis of esophageal carcinoma(squamous cell carcinoma[SCC], Stage II ). He was treated with cisplatin(CDDP)and 5- fluorouracil(5-FU). On the fifth day after administration, he experienced mild disorientation, and early morning on the sixth day, he showed impaired consciousness. Laboratory studies revealed a serum sodium level of 111mEq/L and a serum chloride level of 73mEq/L. The findings of computed tomography and magnetic resonance imaging of the head were unremarkable. Other laboratory studies revealed a plasma vasopressin level of 19.2 pg/mL, a plasma osmolality of 219mOsm/kg, a serum creatinine level of 0.61mg/dL, a serum cortisol level of 27.1 mg/dL, a urine osmolality of 665mOsm/kg, and a urine sodium level of 157.1mEq/L. There were no signs of dehydration, and so the patient was diagnosed with syndrome of inappropriate antidiuretic hormone secretion(SIADH). We discontinued chemotherapy and initiated fluid restriction and sodium supplementation. After this treatment, the patient's consciousness progressively improved. On the fifth day of treatment, laboratory studies revealed a serum sodium level of 138mEq/L and a serum chloride level of 98mEq/L, indicating recovery from hyponatremia.

Gellan sulfate core platinum coil with tenascin-C promotes intra-aneurysmal organization in rats.

The aims of this study were to develop a new coil, gellan sulfate core platinum coil (GSCC), that delivers tenascin-C (TNC) to an aneurysm (GSCC-TNC) and to evaluate the effects on intra-aneurysmal organization. We performed in vitro adsorption tests of TNC to gellan sulfate (GS). GSCC-TNC was produced by immersing GSCC in TNC solution under the following conditions (TNC concentration 10, 50, or 100 µg/mL; TNC immersion time 15, 30, or 60 min) by monitoring intra-aneurysmal organization in a rat blind-ended aneurysm model. In addition, 20 rats randomly underwent implantation of a platinum coil or the GSCC-TNC produced under optimum conditions into an aneurysm, whose organization effects were compared in a blind fashion at 2 weeks post-surgery. GS demonstrated a high affinity to TNC in a dose-dependent fashion (affinity constant = 1.79 × 10(10) (M(-1))). GSCC immersed in 10 µg/mL of TNC solution for 30 and 60 min induced similar and better organization of aneurysmal cavity compared with that for 15 min (the ratio of the organized areas in an aneurysmal cavity-15 min, 27.2 ± 11.8 %; 30 min, 75.6 ± 11.9 %; 60 min, 82.6 ± 19.7 %, respectively) with the preservation of the aneurysmal wall structure, while higher TNC concentrations caused the destruction of the aneurysmal wall. GSCC-TNC produced under 10 µg/mL of TNC solution for 30 min showed a significantly better organization of aneurysms compared with bare platinum coils in rats. A newly developed coil, GSCC-TNC, may be effective for improving intra-aneurysmal organization after coil embolization.

The behavior of ligament cells cultured on elastin and collagen scaffolds.

The ruptured anterior cruciate ligament (ACL) does not heal spontaneously. Therefore, the development of new healing techniques employing tissue engineering is vital. One of the aspects related to tissue-engineered artificial ligaments is the type of cell to be used for the artificial ligament. In this study, ligament cells from the ACL and periodontal ligament (PDL) were evaluated. In addition, we prepared highly oriented extracellular matrix (ECM) fiber scaffolds that mimicked the structure of the ligament and examined the cellular responses to these scaffolds. Elastin-A and collagen were used as the ECM proteins. Although the cells from the PDL (PDL fibroblasts [PDLFs]) showed approximately 2.1-fold higher expression of alkaline phosphatase (ALP; marker of osteogenic differentiation) than the ACL cells, the expression of ligament-related genes (for type I collagen, type III collagen, and tenomodulin) did not differ between PDLFs and ACL cells. Furthermore, the cellular responses (expression pattern of ligament-related genes and ALP activity) to the ECM were similar between ACL cells and PDLFs. In particular, elastin-A upregulated ALP and downregulated tenomodulin (TeM; a ligament marker) in ligament cells. In contrast, collagen maintained TeM expression in ligament cells. These results suggest that elastin-A promotes the osteogenic differentiation of ligament cells and that collagen maintains the phenotype of ligament cells.

Human mesenchymal stem cells differentiate to epithelial cells when cultured on thick collagen gel.

The stem cell niche is crucial to the control of stem cell fate determination in vitro as well as in vivo, and an understanding of these niches is required for the progression of stem cell and tissue engineering. The goal of our study was to commit human mesenchymal stem cells (hMSCs) to the epithelial lineage. To do this, we cultured bone marrow-derived mesenchymal stem cells (MSCs) on plates coated with type I collagen gel with or without 10 µM all-trans retinoic acid (ATRA).We found depth-dependent differentiation of hMSCs to the epithelial lineage, with the thick collagen gel (1900 µm) generating more than 80% cytokeratin-18 (CK-18)-positive cells, whereas the thin collagen gel (100 µm) generated significantly fewer CK-18-positive cells. In addition, we found that supplementation of 10 µM ATRA enhanced CK-18 expression and induced cluster-formation in cells grown on the thick collagen gel. The effect of gel depth on hMSC differentiation appears to be caused by partial cytoskeletal disruption.These results suggest that ATRA and a collagen extracellular matrix may have a synergistic effect on differentiation of human mesenchymal stem cells to epithelial lineage.

Characterization of peritoneal dialysis effluent-derived cells: diagnosis of peritoneal integrity.

To assess the integrity of the peritoneal membrane, we characterized the functionality of the cellular components derived from peritoneal dialysis effluent (PDE). About 3 % of all cells collected from the PDE attached to the plastic dish, and 97.1 ± 3.1 % of the adherent cells expressed CK-18 (PDE-HPMC). A typical cobble-stone-like morphology under neutralized PD solution was obtained over 65 out of 74 primary cultures (88 %) while only 53 % under acidic PD solution in a previous report by Yanez-Mo et al. However, 26.6 ± 10.3 % of PDE-HPMC expressed the EMT marker α-SMA. Transepithelial resistance (TER) as a marker of cell polarity was 34 % lower than that of omentum-derived(OM)-HPMC. We found a significant decrease in the rate of PDE-HPMC proliferation compared to OM-HPMC, accompanied by a significant increase of cell area within the tertiary passage. Comparison of TER, α-SMA and SA-ß-Gal between CAPD durations suggests that cell polarity weakens with increased duration of CAPD, reflecting the occurrence of EMT and cell senescence. We conclude that functional characterization of cellular components in PDE reflects how well the peritoneum is preserved.

Multiple-type dynamic culture of highly oriented fiber scaffold for ligament regeneration.

The ruptured anterior cruciate ligament does not heal spontaneously as it has a low capacity for healing. Therefore, the development of new healing techniques employing tissue engineering is vital. As a potentially new approach for ligament regeneration, this study used a highly oriented fiber scaffold made of elastin and collagen (the mean diameters were 1.7 ± 0.4 µm and 0.5 ± 1.4 µm, respectively), which comprise the extracellular matrix of the ligament. In addition, a multiple-type dynamic culture consisting of a combination of pressure and twist stimulation was performed to examine the influence of mechanical force on the functional maintenance of ligament cells and on the differentiation of ligament cells to osteoblast-like cells. Our results show that a pressure stimulation and elastin A upregulated the expression of alkaline phosphatase (ALP) (a marker of osteogenic differentiation) and promoted the osteogenic differentiation of ligament cells. In addition, the twist stimulation upregulated the expression of type III collagen (the main component of ligament tissue). Furthermore, the combination of pressure and twist stimulation promoted the expression of type III collagen and ALP protein depending on the portion of scaffold.

[Two cases of afferent loop obstruction associated with peritoneal dissemination after total gastrectomy].

We report 2 cases of afferent loop obstruction associated with peritoneal dissemination after total gastrectomy. Case 1: A 57-year-old man, who underwent total gastrectomy with Roux-en Y reconstruction for gastric cancer 5 years earlier, experienced lumbago. Computed tomography scans showed a fluid-filled dilated afferent loop. Bypass surgery was performed after inserting a drainage tube into the afferent loop. Case 2: A 61-year-old woman, who underwent total gastrectomy with Roux-en Y reconstruction for a gastric cancer 2 years earlier, experienced abdominal pain. CT and magnetic resonance imaging scans showed a fluid-filled dilated afferent loop and mass lesion near the Y anastomosis. After percutaneous transhepatic duodenal drainage, a duodenal stent was inserted. Here, we describe 2 cases of afferent loop obstruction, improved surgery, and non-surgical therapy.

Jacalin regulates IgA production by peripheral blood mononuclear cells.

AIMS: In IgA nephropathy, circulating immune complexes containing IgA1 are deposited on the glomerular mesangium, causing mesangial cell proliferation and acceleration of extracellular matrix production. The suppressive effect of jacalin, a galactose-binding lectin, on IgA production in vitro was determined. MATERIALS & METHODS: Normal human peripheral blood mononuclear cells were stimulated with plate-bound anti-CD3 and Th2 stimulation, with or without jacalin. Regulatory and effector cell subsets were determined by flow cytometry, and immunoglobulin production by ELISA. RESULTS: Jacalin increased the ratio of CD4(+)CD25(+)CD152(+) Tregs:effector T cells in peripheral blood mononuclear cell cultures 60-fold. This CD4(+)CD25(+)CD152(+) Treg increase may have inhibited Th2-stimulated IgA production by B cells. CONCLUSION: Immune tolerance induced by jacalin can suppress IgA production.

[Analysis of postoperative pulmonary complications after esophagectomy for esophageal cancer].

We examined factors contributing to an onset of postoperative pulmonary complications following esophagectomy for esophagus cancer. One hundred thirty-two cases of the resected esophageal cancer were studied. We considered the relationship between preoperative patient factors, operative factors, clinical stage factors and postoperative pulmonary complications. Postoperative pulmonary complication was observed in 27 cases (20%). The incidence of postoperative pulmonary complications was significantly higher in patients aged 70 and above and those with a preoperative serum albumin value of less than 4 .0 g/dL. Additionally, these two factors were correlated with an onset of postoperative pulmonary complications in multivariate analyses. A decrease of preoperative serum albumin value was reflecting the chronic poor nutritional condition. Moreover, it was possible that poor nutritional condition served as a prognostic factor of postoperative complications in relation to reduction of cellular immunity. The results indicated that there was a possibility of decreasing an onset of postoperative pulmonary complications using various nutrition managements before operations.

[A case of advanced esophageal cancer patient surviving more than 7 years treated with chemoradiotherapy].

We report here a long-term survival case of advanced esophageal cancer with distant lymph node metastases, treated with definitive chemoradiotherapy (CRT). A man in his 60s with disturbance of swallowing was diagnosed as middle esophageal cancer involving multiple metastases of distant lymph nodes. CRT (combination of 5-FU and nedaplatin every four weeks for four courses with 66 Gy of radiation) was administered. After a completion of CRT, CT scan revealed shrinking metastatic lymph nodes. No tumor but a scar at the site of cancer was observed by endoscopy, and histopathology of biopsy specimen detected no tumor cells. From these results, we diagnosed the curative effect of CRT as complete response. Five years after CRT, a swelling of left inguinal lymph node with uptake of fluorine-18-fluorodeoxyglucose appeared and was extirpated, and the swelling was diagnosed histopathologically as metastasis of esophageal cancer. The patient is surviving with no recurrence for 7 years and 8 months from the first diagnosis. In cases of highly advanced esophageal cancer, a long-term follow-up should be performed.

[A case of advanced esophageal cancer invaded to the trachea with PCR after preoperative chemoradiotherapy, which relapsed at the time of three years and seven months after resection].

A male in his 40s was diagnosed with type-3 advanced esophageal cancer in the upper thoracic and cervical esophagus, which invaded to the trachea. We administered a low-dose FP combination therapy (5-FU and CDDP) along with 40 Gy radiotherapy. This chemoradiotherapy reduced the esophageal tumor significantly, and then we performed subtotal esophagectomy. Histological examination of the resected specimens revealed no residual cancer cells in the primary lesion or regional lymph nodes. No recurrence had occurred for about three years and seven months after the operation. However, CT revealed that the patient had the signs of recurrence (bone and lung), and finally he died four years and eight months after the operation. Preoperative chemoradiotherapy is potentially effective for advanced esophageal cancer invaded to adjacent organs. Although chemoradiotherapy yielded a complete response in our case( an advanced esophageal cancer patient), a patient follow-up is necessary because a recurrence may occur along the way.

[Two cases of complete response of primary esophageal carcinoma treated with 5-FU/CDDP as neoadjuvant chemotherapy].

CASE 1: A 67-year-old man with lower thoracic esophageal carcinoma, T2N0M0, cStage II, underwent neoadjuvant chemotherapy (NAC) with 5-FU/CDDP. After 2 courses of NAC, radical resection of the esophageal carcinoma was performed. Primary tumor was not palpable, and lymph node swelling was not found in the resected specimens. Pathologic examination of the resected specimens revealed no malignant cells in the esophagus. Histologic effect of the NAC was grade 3. We obtained down-staging of carcinoma in T0N0M0, fStage 0. CASE 2: A 58-year-old man with thoracic esophageal cancer, T3N2M0, cStage III, underwent NAC with 5-FU/CDDP. After 2 courses of NAC, radical resection of the esophageal carcinoma was performed. Primary tumor was not found in the resected specimens. Pathologic examination of the resected specimens revealed only an irregular fibrosis of esophageal wall, and no malignant cells in the esophagus. Two lymph node metastasis and surrounding fibrosis was found. We obtained down-staging of carcinoma in T0N2M0, fStage II. We report two cases of complete response of primary esophageal carcinoma treated with 5-FU/CDDP as neoadjuvant chemotherapy.

Three-dimensional invasion of epithelial-mesenchymal transition-positive human peritoneal mesothelial cells into collagen gel is promoted by the concentration gradient of fibronectin.

BACKGROUND: In long-term peritoneal dialysis, myofibroblast-like cells found in the interstitium of the peritoneum are assumed to be a transformed type of mesothelial cell-epithelial-mesenchymal transition-positive [EMT(+)] human peritoneal mesothelial cells (HPMCs)-because they express a mesothelial marker, cytokeratin. However, no direct evidence about how these cells are able to invade from the mesothelium has yet been obtained. AIM: In this study, we aimed to verify whether EMT(+) HPMCs would, in vitro, invade three-dimensionally along certain chemotactic factors. METHODS: We used reverse-transcriptase polymerase chain reaction to measure expression of Snail, E-cadherin, α(5)-integrin, and matrix metalloproteinase 2 (MMP2) messenger RNA (mRNA) in HPMCs exposed to 10 ng/mL transforming growth factor ß1 (TGFß1) and how that expression corresponds to cell motility, as represented by a video movie. We used the Transwell (12 µm pore diameter: Sigma-Aldrich, Tokyo, Japan) to construct a three-dimensional (3D) cell migration chamber. In the lower chamber, a concentration gradient of fibronectin (FN) or albumin(Alb) was formed in 0.1% type I collagen by diffusion (C(0)=22 nmol/L; concentration gradient: C/C(0)=0.7). All cells beneath the membrane were counted 72 hours after 5×10(4) EMT(+) HPMCs (HPMCs after a 48-hour exposure to 10 ng/mL TGFß1) had been spread in the upper chamber. RESULTS: After 72 hours, the increased motility of HPMCs resulting from their exposure to 10 ng/mL TGFß1 had returned to baseline, but they retained an elongated morphology. Expression of Snail and MMP2 mRNA reached maximum at 24 hours. Expression of E-cadherin declined, and expression of α(5)-integrin increased continuously. In the 3D invasion study, significantly enhanced invasion by EMT(+) but not EMT(-) HPMCs was clearly seen in the presence of a FN concentration gradient (p<0.01), although invasion by EMT(+) and EMT(-) HPMCs in the absence of a FN concentration gradient was not statistically significantly different. Compared with the EMT(+) control (no concentration gradient), invasion by EMT(+) HPMCs was 2.1 ± 0.5 times (p<0.05) and 1.4 ± 0.4 times (p=nonsignificant) higher along the FN and Alb concentration gradients respectively. Increased invasion along the FN concentration gradient was significantly inhibited (p<0.05) when the HPMCs were pre-incubated with 5 µg/mL RGDS (a blocker for α(5)-integrin to FN). CONCLUSIONS: We conclude that EMT(+) HPMCs invade collagen gel along the FN concentration gradient because of specific binding to RGDS receptors, which bind integrins such as α(5)-integrin, upregulating invasion-related gene expression associated with synthesis of the cytoskeleton protein α smooth muscle actin.