Variations in the structure and transcription of the mitochondrial atp and cox genes in wild Solanum species that induce male sterility in eggplant (S. melongena)

In order to determine the molecular basis of cytoplasmic male sterility (CMS) in alloplasmic lines of eggplant, the genomic structures and transcription patterns of mitochondrial ATP synthase subunit (atp) and cytochrome oxidase subunit (cox) genes were studied for wild and cultivated eggplants. Alloplasmic eggplant lines with cytoplasms of wild Solanum species showing either anther indehiscent type of CMS or non-pollen production type of CMS were studied with the cultivated eggplant Solanum melongena, used as a control. Southern hybridization of the mitochondrial genes indicated the difference between the two types of CMS and showed complete identity within each type. The cytoplasmic patterns of all wild species differed from that of the cultivated eggplant. Thus, the cytoplasm of the six wild eggplants and the one cultivated eggplant was classified into three groups. Male sterile plants of both types of CMS showed novel transcription patterns of atp1, whereas a different transcription pattern of cox2 was observed only in the anther indehiscent type. Based on these differences, we determined the DNA sequences of about a 4 kbp segment in the atp1 region. Although the coding and 3' flanking regions were almost identical among the cytoplasms, the 5' flanking region was completely different and novel open reading frames (orfs) were found for each of the CMS types and the cultivated eggplant. The cytoplasm of Solanum kurzii inducing the anther indehiscent type CMS had orf312, and those of Solanum aethiopicum and Solanum grandifolium of non-pollen production type CMS had orf218. The correspondence between the transcription patterns of these orfs and phenotypic expression of male sterility strongly suggests that these orfs are causal genes for each type of CMS.

[A new strategy for locally advanced rectal cancer using a nerve-regeneration tube]

In surgery for the treatment of locally advanced rectal cancers affecting the intrapelvic nerves, when an affected nerve is resected in extended surgery to achieve radical cure, the resection results in functional disturbance in the organ it controls. On the other hand, when the nerve remains intact after function-preserving surgery, the risk of local recurrence is high because of possible remnant cancer cells. Thus in performing surgery to treat such cancers, there is a dilemma between the selection of extended surgery or function-preserving surgery. To resolve this, we devised a new strategy in which the cancer is removed radically in extended surgery and organ function is recovered by regeneration of the resected nerve using a nerve-regenerating tube. After animal experiments had confirmed the regeneration of nerve functions with nerve-regenerating tubes, we followed this new strategy to treat 17 patients with locally advanced cancers who underwent extended surgery plus the regeneration of the resected nerve using the nerve-regenerating tube. Nerve function was restored to a significant degree in 16 of the 17 patients.

Abstract 5365: Prolonged survival of patients with advanced renal cancer responding to multi-peptide vaccine IMA901 after single-dose cyclophosphamide

Translational research and the clinical development of therapeutic cancer vaccines requires stronger scientific rationalization. Here we demonstrate how immune response markers as well as biomarkers defining the immune regulatory environment were utilized as guiding tools from discovery to advanced clinical trials of IMA901, a novel therapeutic vaccine for the treatment of renal cell carcinoma (RCC). IMA901 consists of multiple tumor-associated peptides (TUMAPs) confirmed to be naturally presented in human RCC tissue by mass spectrometry, selected using differential transcriptomics and preclinically validated by systematic analysis of immunogenicity with artificial antigen-presenting cells. Two consecutive independent clinical studies in a total of 96 HLA-A*02+ advanced/metastatic RCC patients were conducted. The phase I study revealed that T-cell responses to multiple IMA901 antigens were significantly associated with disease control and negatively associated with the presence of FoxP3+ regulatory T cells (Tregs). The subsequent randomized phase II study demonstrated that pre-treatment with a single low dose of cyclophosphamide (Cy) reduced Treg frequencies and prolonged overall survival (OS) in patients who mounted an immune response to the IMA901 vaccine. Additionally, T-cell responses to multiple IMA901 antigens were again associated with clinical benefit. Furthermore, a comprehensive prognostic and predictive biomarker program was conducted. Among cellular biomarkers, highly significantly elevated levels of myeloid-derived suppressor cells (MDSC), IL-17-/IL-10-secreting T cells and dysfunctional T cells in RCC patients vs. healthy individuals were found. Two MDSC populations (CD14+ HLA-DR- and CD14- CD11b+ CD15+) were significantly negatively associated with survival in vaccinated RCC patients. Interestingly, both MDSC populations were also found to be negatively associated with OS in an independent trial in colorectal cancer patients (N=79) implying a broader role for these MDSC species. Additionally, among over 300 serum biomarkers tested, apolipoprotein A-I (ApoA1) and the chemokine CCL17 were found to be predictive for both immune responses to IMA901 and survival of the RCC patients. The knowledge acquired in these trials was used to design a randomized phase III study. In this ongoing study, IMA901 is combined with the tyrosine kinase inhibitor sunitinib based on the findings that sunitinib downmodulates the two MDSC populations described above. Furthermore, in this phase III study, the relevance of ApoA1/CCL17 will be explored by prospectively defined subgroup analyses.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 5365. doi:1538-7445.AM2012-5365

Pluripotency of a polyploid H1 (ES) cell system without leukaemia inhibitory factor

OBJECTIVES

Tetraploid cells are strictly biologically inhibited from composition of embryos; by the same token, only diploid cells compose embryos. However, the distinction between diploid and tetraploid cells in development has not been well explained. To examine pluripotency of polyploid ES cells, a polyploid embryonic stem (ES)-cell system was prepared.

MATERIALS AND METHODS

Diploid, tetraploid, pentaploid, hexaploid, octaploid and decaploid H1 (ES) cells (2H1, 4H1, 5H1, 6H1, 8H1 and 10H1 cells, respectively) were cultured for about 460 days in L15F10 medium without leukaemia inhibitory factor (LIF). The cells cultured under LIF-free conditions were denoted as 2H1(-), 4H1(-), 5H1(-), 6H1(-), 8H1(-) and 10H1(-) cells, respectively. Pluripotency and gene expression were examined.

RESULTS

Ploidy alteration of H1(-) cells was similar to that of H1 cells. The polyploid H1(-) cells showed positive activity of alkaline phosphatase, suggesting that they maintained pluripotency in vitro without LIF. The polyploid H1(-) cells formed teratocarcinomas in mouse abdomen, suggesting they could differentiate in mouse abdomen in vivo. 2H1, 4H1 and polyploid H1(-) cells expressed nanog, oct3/4 and sox2 genes, suggesting that they fulfilled the criteria of ES cells. Nanog gene was significantly over-expressed in 4H1 and polyploid H1(-) cells, suggesting that overexpression of nanog gene was a characteristic of polyploid H1 cells.

CONCLUSION

Polyploid H1 (ES) cells retained pluripotency in vitro, without LIF with nanog over-expression.

Regeneration and functional recovery of intrapelvic nerves removed during extensive surgery by a new artificial nerve conduit: a breakthrough to radical operation for locally advanced and recurrent rectal cancers

PURPOSE

In the current strategy against locally advanced and recurrent rectal cancers possibly involving intrapelvic nerves, there has been a serious dilemma between extensive surgery and limited surgery. The former can attain high tumor curability by sacrificing the nerve functions while the latter prioritizes the patient quality of life by preserving the nerve functions but with a compromised curability. Here we present a new surgical strategy for locally advanced and recurrent rectal cancers, which realize both high tumor curability and good quality of life.

METHODS

A new artificial nerve conduit (polyglycolic acid collagen tube) developed by in site tissue engineering technology was applied to recovery the disturbed functions after removing the nerves from 11 patients undergoing extensive surgery for intrapelvic advanced or recurrent colorectal cancers. The reconstructed nerves included eight autonomic nerves which are essential for the genitourinary function and three somatic nerves which control the sensation and mobility of the legs.

RESULTS

Out of ten cases followed up more than 2 years and evaluated fully, eight including two report cases showed a functional recovery of the disturbed autonomic and somatic nerves clinically. The nerve function started to recover from 3 to 6 months after the operation and continued to improve with times. No specific complications associated with the nerve repair have been noted.

CONCLUSIONS

The new strategy utilizing the nerve conduit can be a breakthrough in radical operations for locally advanced and recurrent rectal cancers to resolve the problems between tumor curability and the patient quality of life.

DNA-unstable decaploid mouse H1 (ES) cells established from DNA-stable pentaploid H1 (ES) cells polyploidized using demecolcine

OBJECTIVES

DNA content of diploid H1 (ES) cells (2H1 cells) has been shown to be stable in long-term culture; however, tetraploid and octaploid H1 (ES) cells (4H1 and 8H1 cells, respectively) were DNA-unstable. Pentaploid H1 (ES) cells (5H1 cells) established recently have been found to be DNA-stable; how, then is cell DNA stability determined? To discuss ploidy stability, decaploid H1 (ES) cells (10H1 cells) were established from 5H1 cells and examined for DNA stability.

MATERIALS AND METHODS

5H1 cells were polyploidized using demecolcine (DC) and 10H1 cells were obtained by one-cell cloning.

RESULTS

Number of chromosomes of 10H1 cells was 180 and durations of their G(1), S, and G(2)/M phases were 3, 7 and 6 h respectively. Volume of 10H1 cells was double that of 5H1 cells and morphology of 10H1 cells was flagstone-like in shape. 10H1 cells exhibited alkaline phosphatase activity and their DNA content decayed in 91 days of culture. 10H1 cells injected into mouse abdomen formed solid tumours that contained several kinds of differentiated cells with lower DNA content, suggesting that 10H1 cells were pluripotent and DNA-unstable. Loss of DNA stability was explained using a hypothesis concerning DNA structure of polyploid cells as DNA reconstructed through ploidy doubling was arranged in mirror symmetry in a new configuration.

CONCLUSION

In the pentaploid-decaploid transition of H1 cells, cell cycle parameters and pluripotency were retained, but morphology and DNA stability were altered.

Multicenter phase II study of weekly paclitaxel plus S-1 combination chemotherapy in patients with advanced gastric cancer

BACKGROUND

A multicenter phase II study was conducted to evaluate the efficacy and safety of a combination regimen of weekly paclitaxel plus S-1 in patients with advanced gastric cancer.

METHODS

Patients with previously untreated metastatic or recurrent gastric cancer received intravenous paclitaxel 50 mg/m(2) on days 1, 8, and 15, plus oral S-1 40 mg/m(2) b.i.d. on days 1 to 14 followed by 2 weeks off, in a 28-day cycle.

RESULTS

A total of 54 patients were registered. All of them had measurable disease and were determined to be eligible for the present study. Two complete responses and 23 partial responses were confirmed, giving an overall response rate of 46.3%. At a final follow up of 3 years, the median progression-free survival and median overall survival were 6.0 and 14.3 months, respectively. Grade 3 neutropenia occurred in 14 patients, and grade 4 in 1 patient (total, 27.8%). The most serious nonhematological toxicity was diarrhea, where grade 3 occurred in 5 patients (9.3%). There were no treatment-related deaths.

CONCLUSION

A combination of weekly paclitaxel plus S-1 was found to be well tolerated and effective in patients with advanced gastric cancer. Further investigation with comparative trials is needed for confirmation.

Gastric hyposecretion in esophageal squamous-cell carcinomas

Recently, gastric fundic atrophy is reported to be an independent risk factor for esophageal squamous-cell carcinoma (ESCC). The aim of this study is to investigate the acid secretory level in ESCC in a case-control study. From April 2004 to March 2008, 100 consecutive subjects with early ESCC and 100 age- and sex-matched asymptomatic controls were prospectively enrolled. Gastrin-stimulated acid output was assessed by endoscopic gastrin test. Conditional regression analyses were used to adjust for other potential confounders. Multivariate analyses revealed a strong association between profound hypochlorhydria and ESCC with odds ratio (95% confidence interval): 6.0 (1.9-18.4). The association remained significant after adjusting for the effect of gastric atrophy as a covariate. The association became stronger as the ESCC developed more distal site of the esophagus. This study indicates that profound hypochlorhydria is a strong independent risk factor for ESCC even after adjusting for the influence of gastric atrophy.

Development of a laser-focused ion beam combination machine

We have developed a laser and focused ion beam (FIB) compound system to process an optical component device with an ultrafine precision minute surface structure and a micromedical device. This machine consists of an FIB and three types of lasers with an atomic force microscope. This system can fabricate decamicrometer area by laser and submicrometer area by FIB at one chuck. When processing the press mold die of a microlens array (10x10) in a glasslike carbon with a femtosecond laser, a diameter of 3.2 microm and depth of 0.43 microm are obtained. However, the surface roughness is more than Rz=0.5 microm. After this process, we finished this surface with the use of the FIB. As a result, the surface roughness is less than Rz=0.05 microm.

Histologic and electrophysiological study of nerve regeneration using a polyglycolic acid-collagen nerve conduit filled with collagen sponge in canine model

OBJECTIVES

To determine the rate of achieving electrophysiologically proved functional recovery by autonomic nerve regeneration, with the aid of an artificial nerve conduit.

METHODS

A polyglycolic acid (PGA) collagen nerve conduit filled with collagen sponge was interposed in a 10-mm-long gap of the right hypogastric nerve (HGN) in 16 dogs. Histologic evaluation of nerve regeneration and electrophysiological analysis at 2 weeks and 2, 3, 4, 5, 6, 7, and 8 months (n = 2, each) after surgery was performed, measuring the responses for the spermatic ducts (SD), bladder neck (BN), and prostate contraction, by stimulating the right lumbar splanchnic nerves (LSNs) from L2 to L4, after transection of the left HGN to eliminate substitutive pathways.

RESULTS

Two months after implantation, the regenerated neurofilaments were successfully extended through the graft from the proximal-to-distal direction. In 2 control dogs, electrostimulation of the right LSNs induced elevation of the intraluminal pressure of the SD, elevation of the BN pressure, and prostate contraction. No responses were observed in all dogs up to 6 months of follow-up after implantation. In 1 dog with a 7-month follow-up, electrostimulation elicited elevation of BN pressure alone. In both dogs with an 8-month follow-up, electrostimulation induced similar responses to control in all SD, BN, and prostate; however, after excision of the area of the interposed right HGN, no response was observed.

CONCLUSIONS

These results proved that regeneration of a 10-mm gap of the HGN, using a novel PGA-collagen nerve conduit could be achieved within 8 months.

Regeneration of peritoneum using amniotic membrane to prevent postoperative adhesions

BACKGROUND/AIMS

Adhesions following intraperitoneal surgery are frequent causes of small bowel obstruction. Attempts to prevent postoperative adhesions have mostly proven disappointing clinically. Currently used by ophthalmologists in ocular surface disorders, amniotic membrane transplantation can reduce inflammation and promote re-epithelization. We used amniotic membrane for facilitating peritoneal regeneration and prevention of adhesions with surgical trauma.

METHODOLOGY

20 rats were randomized in equal number into treatment or control groups. Seven days after operation, the incidence and severity of adhesions were evaluated. Histologic and immunohistochemical analyses were examined at 1, 4, 10 weeks after operation.

RESULTS

While severe adhesions were observed after 1 week between the cecum and surrounding organs in the control group, adhesion formation was significantly reduced in the amniotic membrane group. Histologic examination demonstrated that free-floating myofibroblasts in the peritoneal cavity attached to surfaces of amniotic membrane grafts to form a layered structure. Free-floating mesothelial cells were incorporated into the regenerating mesothelium on the myofibroblast layer in 4 weeks, while implanted amniotic membrane grafts were absorbed by 10 weeks. In the amniotic membrane group the cecum appeared nearly normal.

CONCLUSIONS

Amniotic membrane grafts reduced intraperitoneal adhesions after surgical trauma, were well absorbed, and served as a substrate for regenerating mesothelium.

Involvement of REG Ialpha protein in the regeneration of ductal epithelial cells in the minor salivary glands of patients with Sjögren's syndrome

The regenerating gene (Reg) was originally isolated from regenerating rat pancreatic islets and revealed recently to constitute a multi-gene family in humans. REG Ialpha protein is known to be overexpressed not only in various human inflammatory diseases but also in various experimental models of inflammation in animal tissues. However, its involvement in pathophysiology of the minor salivary gland (MSG) is not clear. We investigated REG Ialpha expression in the MSG of patients with primary Sjögren's syndrome (SS) and assessed its role in ductal epithelial cell proliferation in such tissues. Lip biopsy specimens were obtained from 40 patients with primary SS and examined using immunohistochemistry for REG Ialpha protein, Ki67 and single-strand DNA (ssDNA). The relationships among clinicopathological factors and expression of REG Ialpha protein, Ki67 and ssDNA in the MSG were then analysed. REG Ialpha protein was expressed rarely in ductal epithelial cells of the normal MSG but was apparently overexpressed in those of patients with SS. The labelling indices for both Ki67 and ssDNA in the ductal cells of the MSGs were significantly higher in SS patients than in controls. Moreover, these labelling indices were significantly higher in REG Ialpha-positive than in negative SS patients. REG Ialpha protein may play a role in the regeneration of ductal epithelial cells in the MSGs of patients with SS.

Establishment of a tetraploid Meth-A cell line through polyploidization by demecolcine but not by staurosporine, K-252A and paclitaxel

Polyploid cells are made by DNA reduplication without cell division, however, it is not easy to establish polyploid mammalian cell lines. It is worth studying the difference in cell character between hyperploid and parent cell lines. Meth-A cells were polyploidized by demecolcine, K-252a, staurosporine and paclitaxel. The cell-cycle responses of highly polyploid Meth-A cells after the removal of the drugs were examined by flow cytometry (FCM). Meth-A cells were highly polyploidized by these drugs. The polyploid Meth-A cells gradually decreased in ploidy after the drug release. A tetraploid Meth-A cell line was established only from the demecolcine-induced polyploid Meth-A cells. The duration of G1, S and G2/M phases of the tetraploid cell line were mostly the same as those of the parent diploid cells, except that the G2/M phase was 1.5 h longer. The chromosome number of tetraploid Meth-A cell line was about twice of the diploidy. A tetraploid Meth-A cell line was established.

Intrathoracic esophageal replacement by in situ tissue-engineered esophagus

OBJECTIVE

This study aimed to evaluate in situ tissue-engineered esophagus in a canine model after experimental resection and replacement of a full circumferential defect of the intrathoracic esophagus.

METHODS

Two types of scaffolding were fabricated. In the KF(+) group (n = 6), oral keratinocytes and fibroblasts cultured on human amniotic membrane were sheeted on polyglycolic acid felt with smooth muscle tissue and were then rolled around tubes. In the KF(-) group (n = 6), the same procedure was followed, but the keratinocytes and fibroblasts were omitted. Both scaffolds were wrapped in omentum and implanted in the abdomen. In the KF(+) group, at 3 weeks after implantation, the scaffold developed into a tube with a well-differentiated lumen of stratified squamous cells surrounded by a thick smooth muscle-like tissue (in situ tissue-engineered esophagus). A part of the esophagus was resected and replaced by the graft in the same dogs.

RESULTS

In the KF(-) group, strictures developed after esophageal replacement, with almost complete obstruction within 2 to 3 weeks. In contrast, in the KF(+) group, the in situ tissue-engineered esophagus showed good distensibility and the dogs remained without feeding problems through 420 days. Esophageal peristalsis transferred food to the stomach, despite the absence of peristaltic activity in the in situ tissue-engineered esophagus itself. The thickness of the squamous epithelial layer and the smooth muscle layer of the in situ tissue-engineered esophagus were similar to that of the adjacent native esophagus.

CONCLUSION

The in situ tissue-engineered esophagus can successfully replace the intrathoracic esophagus, and this procedure may offer a promising surgical approach to esophageal diseases.

Efficacy of prophylactic extended lymphadenectomy with gastrectomy for patients with node-negative advanced gastric carcinoma

BACKGROUND/AIMS

Extended lymphadenectomy with gastrectomy is widely performed for patients with advanced gastric carcinoma. However, the therapeutic value of prophylactic extensive lymphadenectomy in patients with node-negative advanced gastric cancer is controversial.

METHODOLOGY

We retrospectively analyzed 221 patients who underwent curative gastrectomy for advanced gastric carcinoma without lymph node metastasis to evaluate the effect of prophylactic extended lymphadenectomy on postoperative survival. The postoperative survival rate of patients who underwent extended lymphadenectomy was compared with that of patients who underwent limited lymphadenectomy. Predictive risk factors for tumor recurrence and recurrent patterns also were analyzed.

RESULTS

Extended lymphadenectomy improved the postoperative survival rate of patients with advanced tumors even when lymph node spread was absent. Whether or not prophylactic extended lymphadenectomy was performed significantly affected tumor recurrence in patients with node-negative advanced gastric carcinoma.

CONCLUSIONS

Extensive lymphadenectomy with gastrectomy prolongs survival of patients with node-negative advanced tumors.

Overexpression of RegIV in peritoneal dissemination of gastric cancer and its potential as A novel marker for the detection of peritoneal micrometastasis

BACKGROUND

Regenerating gene type IV (RegIV) is a candidate marker for cancer and inflammatory bowel disease. In this study, its potential as a novel marker for the detection of gastric cancer peritoneal micrometastases was examined.

PATIENTS AND METHODS

RegIV mRNA levels in the peritoneal washes of 95 gastric cancer patients and 22 with benign disease were quantified by real-time RT-PCR. To examine whether expression of RegIV enhance tumorigenicity or not, thirty two mice were injected intraperitoneally or subcutaneously with RegIV transfectants of TMK-1 cells, parental TMK-1 cells, or neomycin control transfectants.

RESULTS

RegIV expression was markedly higher in patients with peritoneal metastases compared to those without. The level of RegIV mRNA in gastric cancer patients was related to the extent of wall penetration. A cut-off value for RegIV-positive expression was based on an analysis of negative control patients with benign disease, and gastric cancer patients above the cut-off value constituted the micrometastasis (MM+) group. Based on this criteria, 3 out of 43 T1 or T2 cases were MM+ (93% specificity). Among 15 patients with peritoneal dissemination (7 out of 15 cases were positive by cytology), 14 cases were positive for RegIV expression (93% sensitivity), while analysis of carcinoembryonic antigen (CEA) mRNA failed to detect micrometastases in 4 cases (73% sensitivity). Combined analysis of CEA and RegIV improved the accuracy of diagnosis to 100%. The prognosis of RegIV-positive cases was significantly worse than that of RegIV-negative cases. Multivariate analysis using the Cox proportional hazards model suggested that RegIV may be an independent prognostic factor. Stable expression of RegIV significantly enhanced peritoneal metastasis in an animal model of gastric cancer.

CONCLUSION

These findings suggest that RegIV mRNA expression has the potential to serve as a novel marker for detecting peritoneal dissemination in gastric cancer.

Nanogel DDS enables sustained release of IL-12 for tumor immunotherapy

For a valid cytokine immunotherapy of malignancies, a suitable delivery system that ensures slow-release of cytokines is required, because short half-life in vivo of the molecules ruins therapeutic efficacy while causing severe systemic toxic effects. We previously showed that the cholesterol-bearing pullulan (CHP)-based hydrogel nanoparticles, or nanogel, encapsulates, stabilizes and releases various molecules. Here we applied this nanogel to administration in vivo of interleukin-12 (IL-12). Recombinant murine IL-12 (rmIL-12) was successfully incorporated into CHP nanogel simply by incubated with CHP at room temperature. After subcutaneously injected into mice, the CHP/rmIL-12 complex led to a prolonged elevation in IL-12 concentration in the sera. Repetitive administrations of the CHP/rmIL-12, but not rmIL-12 alone, induced drastic growth retardation of preestablished subcutaneous fibrosarcoma without causing any serious toxic event. The present study proposes a novel therapeutic intervention technology, taking advantage of slow and sustained release of bioactive cytokines from the self-assembling biocompatible nanoparticles.

Chloride ions control the G1/S cell-cycle checkpoint by regulating the expression of p21 through a p53-independent pathway in human gastric cancer cells

The aim of the present study is to investigate whether the chloride affects cell growth and cell-cycle progression of cancer cells. In human gastric cancer MKN28 cells, the culture in the Cl(-)-replaced medium (replacement of Cl(-) by NO(3)(-)) decreased the intracellular chloride concentration ([Cl(-)](i)) and inhibited cell growth. The inhibition of cell growth was due to cell-cycle arrest at the G(0)/G(1) phase caused by diminution of CDK2 and phosphorylated Rb. The culture of cells in the Cl(-)-replaced medium significantly increased expressions of p21 mRNA and protein without any effects on p53. These observations indicate that chloride ions play important roles in cell-cycle progression by regulating the expression of p21 through a p53-independent pathway in human gastric cancer cells, leading to a novel, unique therapeutic strategy for gastric cancer treatment via control of [Cl(-)](i).

Regeneration of skeletal muscle using in situ tissue engineering on an acellular collagen sponge scaffold in a rabbit model

Because of the limited ability of skeletal muscle to regenerate, resection of a large amount of muscle mass often results in incomplete recovery due to nonfunctional scar tissue. The aim of this study was to regenerate skeletal muscle using in situ tissue engineering in a rabbit model. In 18 male rabbits, a muscle defect (1.0 x ~1.0 x ~0.5 cm) was created in the vastus lateralis of both legs. A piece of cross-linked atelocollagen sponge was then inserted into the defect in one leg, whereas the defect in the other leg was left untreated. Both defects were finally covered with fascia. Twenty-four weeks after surgery, the defect that had been filled with the cross-linked atelocollagen sponge scaffold showed mild concavity and slight adhesion to the fascia, while the control side showed severe scar formation and shrinkage. Histologically, the regenerating myofibers at the site containing the collagen sponge were greater in number, diameter, and length than those at the control site. These results indicate that cross-linked atelocollagen sponge has the potential to act as a scaffold for muscle tissue regeneration.

Lack of synchrony among multiple nuclei induces partial DNA fragmentation in V79 cells polyploidized by demecolcine

The nuclear morphology of polyploidized cells was examined in V79 Chinese hamster cells polyploidized by demecolcine or K-252a, inhibitors of spindle fibre formation and protein kinases, respectively. A variety of nuclear morphologies, including multinuclei, were observed in V79 cells polyploidized by demecolcine but not by K-252a, which produced mononuclear cells. A lack of synchrony in the nuclear cycle was observed among nuclei in multinuclear polyploidized cells. Partial DNA fragmentation, defined as DNA fragmentation of a nucleus in a multinuclear cell, was detected using the TUNEL method in V79 cells polyploidized by demecolcine but not by K-252a. Apoptosis occurred earlier in cell populations treated with demecolcine than in these treated with K-252a once the drugs were removed from the medium, suggesting that polyploidized cells with separate nuclei tend to apoptose earlier than those with mononuclei.