Interleukin-6 is required for cell cycle arrest and activation of DNA repair enzymes after partial hepatectomy in mice.

BACKGROUND: Interleukin-6 (IL-6) has been shown to be vital for liver regeneration, however the specific mechanisms and factors involved remain incompletely defined. The present study aimed to investigate whether IL-6 exerts its protective effects via arresting the cell cycle allowing base excision and repair of oxidized DNA after hepatectomy. RESULTS: Following seventy percent partial hepatectomy (PH) in wild type (WT) mice IL-6 serum levels increased reaching peak levels at 3 hours. This was associated with markers of cell cycle arrest as p21 expression was increased and cyclin D1 and proliferating cell nuclear antigen (PCNA) expression decreased. In the absence of IL-6, markers of cell cycle arrest were absent and the number of bromodeoxyuridine (BrdU) positive cells was significantly higher at 28, 32 and 36 hours after PH. The mRNAs for DNA repair enzymes, including Neil-1, 8-oxodGTPase, OGG1, Apex1, and UDG (DNA glycosylase) were increased 2 to 4 fold in WT mice at 6 and/or 12 hours after PH compared to IL-6 knockout (KO) mice. The protein levels of Neil1 and OGG1 were also significantly increased in WT mice compared to KO mice. Pathological changes were far greater and survival was less in IL-6 KO mice than in WT mice. Administration of IL-6 in KO mice restored p21 and DNA repair enzyme expression to wild-type levels and survival was improved. CONCLUSIONS: IL-6 caused cell cycle arrest and delayed proliferation during the first day after PH. This delay was associated with the activation of DNA repair enzymes resulting in accurate replication and restoration of hepatic mass.

[The efficacy of neoadjuvant chemotherapy with S-1/CDDP (SP) to the patients with large type 3 and type 4 gastric cancer].

Here, I examined the efficacy of neoadjuvant chemotherapy( NAC) with S-1/CDDP( SP) in my hospital. The subjects were 8 patients with advanced gastric cancer who had undergone NAC since 2007 (7 men and 1 woman; median age, 70 years). The staging before the treatment was Stage II A: 1 patient, II B: 2 patients, III B: 3 patients, III C: 1 patient, and IV: 1 patient. The macroscopic type of 3 and 5 patients was large type 3 and type 4, respectively. Gastrectomy was performed following the NAC with SP. The NAC response rate was 62.5%. In the histological response criteria, 1 patient was grade 0, 2 patients were grade 1a, 2 patients were grade 1b, and 3 patients were grade 2. Adverse events following the NAC were in the acceptable range. We noted that the presence of Stage IV or grade 0 histological response criteria to NAC indicated poor prognosis. Thus, I believe that preoperative surgery after NAC in Stage III gastric cancer should be considered to be curative.

[A case that showed an improved quality of life for rectal gastrointestinal stromal tumor patient treated with cytoreductive surgery].

A 49-year-old man was admitted to another hospital with the complaint of difficulty in defecating. He underwent laparotomy, and investigation of the biopsy revealed a huge intraperitoneal tumor. He began to take imatinib in April 2008 following a diagnosis of gastrointestinal stromal tumor (GIST), but the tumor increased in size. He was referred to our hospital for oral administration of sunitinib to reduce the tumor size. The tumor was 30 cm in diameter, and there were several peritoneal metastases around the liver. He began to take sunitinib in February 2009. The tumor increased in size from August 2010 but a partial remission was noted. We performed cytoreductive surgery in April 2011 as palliative care, but the tumor size increased again in October. We performed cytoreductive surgery again, but he died in December 2011. Although cytoreductive surgery for GIST is a potential treatment option, we suggest supportive care.

[A case of type 4 advanced gastric cancer treated by S-1 simple suspension method with CDDP].

S-1 is a key drug for advanced, recurrent gastric cancer. It is difficult to administer S-1 for inoperable gastric cancer with stenosis. We report that a simple suspension method allows administration of S-1 for improved quality of life. The patient was a 65-year-old woman. She consulted a doctor regarding her poor food intake, and had a medical examination with chest-abdominal CT and gastrofiberscopy. She was diagnosed as type 4 gastric cancer with esophageal invasion. It was difficult for her to drink a cup of water due to the stenosis, but we could insert a 6 Fr-Elemental Diet (ED) tube into her stomach. S-1 was dissolved by the simple suspension method. She received combination chemotherapy of S-1 100mg/body (day 1-21) and CDDP 80 mg/body (day 8). After two courses, her intake was much improved; she was able to eat rice porridge and was discharged with improved quality of life. S-1 suspension with ED tube was effective for advanced gastric cancer with stenosis.

Amelioration of oxidative mitochondrial DNA damage and deletion after renal ischemic injury by the KATP channel opener diazoxide.

Renal ischemia was induced in the rat by constriction of the renal artery for 45 min, and the ability of the ATP-sensitive K(+) (K(ATP)) channel opener diazoxide (DZ) to ameliorate renal ischemia-reperfusion (I/R) injury was evaluated. In this model, blood urea nitrogen and creatinine were elevated 2 days after I/R injury but returned closer to normal levels by 7 days after reperfusion. Histological staining for reactive oxygen species (ROS) was clearly positive and oxidized DNA, detected by the presence of the stable adduct 8-hydroxy-2'-deoxyguanosine, was clearly present in the cytoplasm of tubular cells after 1 h of reperfusion and declined 7 days after reperfusion. This finding was confirmed by ELISA, which detected 8-hydroxy-2'-deoxyguanosine in the mitochondrial fraction of kidney homogenates. Despite evidence of improved function measured by blood urea nitrogen and creatinine 7 days after reperfusion, the early changes in tubules were alarming. Mitochondrial DNA showed the common deletion, and the number of TdT-mediated dUTP nick-end label-positive tubular cells increased. Activation of caspase-3 continued, and abnormal levels of ROS were found in the mitochondrial fraction of cellular homogenates. Treatment with DZ before ischemia reduced or prevented the acute and subacute deleterious effects associated with renal I/R injury. We conclude that excess production of ROS by mitochondria on reperfusion is a major upstream event in renal reperfusion injury and that DZ functioned by preventing ROS accumulation in the mitochondria after I/R injury, thereby reducing oxidative stress as measured by the presence of oxidized mitochondrial DNA and features of apoptosis.

[Long survival and effective treatment of unresectable gastric cancer by TS-1 based chemotherapy with a sequential combination].

We report a case of peritoneal cancer dissemination and cytological appearance of cancer cells with Type 4 gastric cancer. Treatment with unichemotherapy and combination chemotherapy with TS-1 proved successful. The patient was a 58-year-old female,who complained of abdominal pain. She was diagnosed as unresectable Type 4 gastric cancer, T 3 NxH 0 P 1 CY 1 M 0, Stage IV (cytology: Class V). Thirteen days after surgery, chemotherapy with TS-1 (80 mg/body/day, 4 weeks) at 2-week intervals in 1 course was performed. However, due to side effects with marrow restraint of grade 1, we changed to the following chemotherapy regimen: TS-1 (80 mg/body/day, 2 weeks) at 4-week intervals as 1 course (23 courses in total). After 16 courses, a partial response (PR) was noted. As additional therapy to recover tumor marker (CA19-9) after 21 courses, combination chemotherapy with TS-1 (80 mg/body/day, 2 weeks) and CDDP (25 mg/body/day, day 1, 8, 15 drip infusion) was performed as one course. This chemotherapy was then performed in 3 courses and tumor markers did not deteriorate, so we changed docetaxel (DOC) (50 mg/body/day(day 1)) to CDDP, and tumor markers returned to the normal value. No recurrence and no side effects appeared (hematological or non-hematological) during this combination chemotherapy.

[Bone metastasis of gastric cancer].

We evaluated 19 patients with bone metastasis after surgery for gastric cancer. In a number of cases, the located in the tumor was U and M region, of macroscopic 3, and the histological type was poorly-differentiated adenocarcinoma with high-grade of lymphatic invasion. The major symptom was lumbago and back pain. The serum AFP level was high in 73.7% of the cases, and LDH was high in 47.7%. The metastatic lesion was predominantly seen in the bone with red pulp such as lumbar and thoracic vertebra and rib. The median survival time was 189 days (range: 24-509) with a poor prognosis. However, newly developed anticancer drugs were very effective for some cases, indicating that such chemotherapy should be tried for cases with bone metastasis.

Measurement of serum thymidine phosphorylase levels by highly sensitive enzyme-linked immunosorbent assay in gastric cancer.

Thymidine phosphorylase (TP) is an enzyme that converts 5'-DFUR to 5-FU and also acts as an angiogenic factor. Measurement of serum TP levels has recently become possible by highly sensitive enzyme-linked immunosorbent assay (ELISA). We examined 38 patients with gastric adenocarcinoma to measure serum TP levels by highly sensitive ELISA method and tissue TP levels by conventional ELISA. In addition, immunohistochemical staining of normal and cancer tissues was also performed. Serum TP levels in patients with stages III and IV and inoperable or recurrent cancer were significantly higher than those in healthy controls. A high correlation was found between serum TP levels and tumor TP levels (r=0.65, p<0.0001). Moreover, serum TP levels were about 1/2500 of tumor TP levels. Tissue TP values in tumor were significantly higher than those in normal tissue. On the other hand, no significant differences among the cancer stages were found in either serum or tumor tissue. In conclusion, we demonstrate that serum TP levels strongly reflect tumor TP levels, and it may predict clinicopathological factors, prognosis, or sensitivity of anti-cancer drugs.