Masahiko Nishizaki

Recent studies have indicated that angiogenesis may be regulated, in part, by p53 tumor suppressor gene function. We hypothesized that wild-type p53 replacement would down-regulate vascular endothelial growth factor (VEGF) expression and inhibit angiogenesis. KM12L4 and SW620, human colon cancer cell lines with p53 mutations, were transduced with a replication-defective adenoviral vector containing the wild-type p53 gene (Ad5/CMV/p53). Reverse transcription-PCR confirmed the presence of p53 in Ad5/CMV/p53-transduced cells. Transduction of colon cancer cells with wild-type p53 decreased VEGF RNA expression compared with that of controls. The decrease in VEGF expression in SW620 cells was dose dependent, with a 49% decrease observed at a multiplicity of infection of 50, and a 71% decrease observed at a multiplicity of infection of 100. Similar effects were seen in KM12L4 cells. VEGF supernatant protein levels were significantly reduced compared with those in nontransduced controls 48 h after the introduction of wild-type p53. Ad5/CMV/p53 inhibited tumor cell-induced angiogenesis in vivo. Restoration of wild-type p53 expression may decrease tumor growth by inhibiting the angiogenic response. These findings may explain, in part, the bystander effect seen with p53 tumor suppressor gene therapy.

A group of candidate tumor suppressor genes (designated CACNA2D2, PL6, 101F6, NPRL2, BLU, RASSF1, FUS1, HYAL2, and HYAL1) has been identified in a 120-kb critical tumor homozygous deletion region (found in lung and breast cancers) of human chromosome 3p21.3. We studied the effects of six of these 3p21.3 genes (101F6, NPRL2, BLU, FUS1, HYAL2, and HYAL1) on tumor cell proliferation and apoptosis in human lung cancer cells by recombinant adenovirus-mediated gene transfer in vitro and in vivo. We found that forced expression of wild-type FUS1, 101F6, and NPRL2 genes significantly inhibited tumor cell growth by induction of apoptosis and alteration of cell cycle processes in 3p21.3 120-kb region-deficient (homozygous) H1299 and A549 cells but not in the 3p21.3 120-kb region-heterozygous H358 and the normal human bronchial epithelial cells. Intratumoral injection of Ad-101F6, Ad-FUS1, Ad-NPRL2, and Ad-HYAL2 vectors or systemic administration of protamine-complexed vectors significantly suppressed growth of H1299 and A549 tumor xenografts and inhibited A549 experimental lung metastases in nu/nu mice. Together, our results, coupled with other studies demonstrating a tumor suppressor role for the RASSSF1A isoform, suggest that multiple contiguous genes in the 3p21.3 120-kb chromosomal region may exhibit tumor suppressor activity in vitro and in vivo.

Kuroda, Shinji MD, PhD; Nishizaki, Masahiko MD, PhD; Kikuchi, Satoru MD, PhD; Noma, Kazuhiro MD, PhD; Tanabe, Shunsuke MD, PhD; Kagawa, Shunsuke MD, PhD; Shirakawa, Yasuhiro MD, PhD; Fujiwara, Toshiyoshi MD, PhD Author Information

Abstract Aim As a result of the difficulty in effective prevention of gastroesophageal reflux, no standard reconstruction procedure after proximal gastrectomy ( PG ) has yet been established. The double‐flap technique ( DFT ), or Kamikawa procedure, is an antireflux reconstruction procedure in esophagogastrostomy. The efficacy of DFT has recently been reported in several studies. However, these were all single‐center studies with a limited number of cases. Methods We conducted a multicenter retrospective study in which patients who underwent DFT , irrespective of disease type and reconstruction approach, at each participating institution between 1996 and 2015 were registered. Primary endpoint was incidence of reflux esophagitis at 1‐year after surgery, and secondary endpoint was incidence of anastomosis‐related complications. Results Of 546 patients who were eligible for this study, 464 patients who had endoscopic examination at 1‐year follow up were evaluated for reflux esophagitis. Incidence of reflux esophagitis of all grades was 10.6% and that of grade B or higher was 6.0%. Male gender and anastomosis located in the mediastinum/intra‐thorax were independent risk factors for grade B or higher reflux esophagitis (odds ratio [ OR ]: 4.21, 95% confidence interval [ CI ]: 1.44‐10.9, P = 0.0109). Total incidence of anastomosis‐related complications was 7.2%, including leakage in 1.5%, strictures in 5.5% and bleeding in 0.6% of cases. Laparoscopic reconstruction was the only independent risk factor for anastomosis‐related complications ( OR : 3.93, 95% CI : 1.93‐7.80, P = 0.0003). Conclusion Double‐flap technique might be a feasible option after PG for effective prevention of reflux, although anastomotic stricture is a complication that must be well‐prepared for.