Takehide Akiyama

Interaction between leukemic-cell VLA-4 and stromal fibronectin is a decisive factor for minimal residual disease of acute myelogenous leukemia

Bone-marrow minimal residual disease (MRD) causes relapse after chemotherapy in patients with acute myelogenous leukemia (AML). We postulate that the drug resistance is induced by the attachment of very late antigen (VLA)-4 on leukemic cells to fibronectin on bone-marrow stromal cells. We found that VLA-4-positive cells acquired resistance to anoikis (loss of anchorage) or drug-induced apoptosis through the phosphatidylinositol-3-kinase (PI-3K)/AKT/Bcl-2 signaling pathway, which is activated by the interaction of VLA-4 and fibronectin. This resistance was negated by VLA-4-specific antibodies. In a mouse model of MRD, we achieved a 100% survival rate by combining VLA-4-specific antibodies and cytosine arabinoside (AraC), whereas AraC alone prolonged survival only slightly. In addition, overall survival at 5 years was 100% for 10 VLA-4-negative patients and 44.4% for 15 VLA-4-positive patients. Thus, the interaction between VLA-4 on leukemic cells and fibronectin on stromal cells may be crucial in bone marrow MRD and AML prognosis.

GST-π gene-transduced hematopoietic progenitor cell transplantation overcomes the bone marrow toxicity of cyclophosphamide in mice

Autologous transplantation of bone marrow cells (BMCs) transduced with the multidrug resistance 1 (MDR1) gene or dihydrofolate reductase (DHFR) gene has already been applied in clinical chemoprotection trials. However, anticancer drugs frequently used in high-dose chemotherapy (HDC), such as alkylating agents, are not relevant to MDR1 or DHFR gene products. In this context, we have previously reported that glutathione S-transferase-pi (GST-pi) gene-transduced human CD34(+) cells showed resistance in vitro against 4-hydroperoxicyclophosphamide, an active form of cyclophosphamide (CY). In the present study, a subsequent attempt was made in a murine model to evaluate the effectiveness of transplantation of GST-pi-transduced BMCs to protect bone marrow against high-dose CY. The gene transfection was carried out retrovirally, employing a recombinant fibronectin fragment. Transfection efficiency into CFU-GM was 30%. After the transplantation, recipient mice (GST-pi mice) received three sequential courses of high-dose CY. As the chemotherapy courses advanced, both shortening of recovery period from WBC nadir and shallowing of WBC nadir were observed. In contrast to the fact that three of seven control mice died, possibly due to chemotoxicity, all seven GST-pi mice were alive after the third course, at which point the vector GST-pi gene was detected in 50% of CFU-GM derived from their BMCs and peripheral blood mononuclear cells. When BMCs obtained from these seven mice were retransplanted into secondary recipient mice, 20% of CFU-GM from BMCs showed positive signals for vector GST-pi DNA after 6 months. These data indicate that the GST-pi gene can confer resistance to bone marrow against CY by being transduced into long-term repopulating cells.

Selective Embolization of the Splenic Vein in Patients with Hepatic Encephalopathy and Splenorenal Shunt

Obliteration of portal-systemic shunts is effective for portosystemic encephalopathy but is often associated with complications such as retention of ascites and worsening of esophageal varices. Selective embolization of the splenic vein was performed on six patients with hepatic encephalopathy and splenorenal shunts. Hepatic encephalopathy was not observed in four patients after the procedure. Neither retention of ascites nor rupture of esophageal varices was observed because postoperative elevation of portal venous pressure was not as great as that seen when shunt obliteration is performed. This procedure can be an effective and safe treatment option for hepatic encephalopathy with a splenorenal shunt.

Advanced pancreatic carcinoma showing a complete response to arterial infusion chemotherapy

We report a patient with advanced carcinoma of the pancreatic body and tail with multiple liver metastases who showed a complete response to hepatic and splenic arterial infusion chemotherapy (HSAIC) with gemcitabine and 5-fluorouracil, following transcatheter peripancreatic arterial embolization (TPPAE) and partial splenic embolization (PSE). Nonresectable advanced pancreatic carcinoma tends to have a low response to medical treatment, with the median survival time being 6 months or less for stage IV cases. We disclose herein that the median survival time of patients receiving HSAIC after TPPAE is more than three times longer than the survival time attained with conventional treatments. However, in patients with advanced carcinoma of the pancreatic tail, for which TTPAE is not applicable, survival times remain low. Thus, in the patient described here, we also performed embolization of the left gastric and short gastric arteries as well as PSE to increase the flow within the great pancreatic and caudal pancreatic arteries via the splenic artery, and gemcitabine and 5-fluorouracil were administered via the splenic artery. As a result of these procedures, marked reduction in the advanced carcinoma of the pancreatic body and tail and of liver metastases was attained.

Long-term survival and late-onset complications of cancer patients treated with high-dose chemotherapy followed by autologous peripheral blood stem cell transplantation

The antitumor effect of high-dose chemotherapy (HDC) followed by autologous peripheral blood stem cell transplantation (auto-PBSCT) is considered superior to that of conventional chemotherapy. However, the long-term benefits of this strategy in Japan remain unclear.Therefore, in this study, 109 cancer patients enrolled between 1989 and 1999 were treated with HDC and auto-PBSCT. Patients were evaluated for long-term survival and late-onset complications, including secondary malignancy. The mean number of CD34+ cells harvested per apheresis was larger in the group receiving high-dose cytosine arabinoside or high-dose etoposide plus granulocyte colony-stimulating factor (G-CSF) than in the group receiving conventional chemotherapy plus G-CSF. The 5-year overall survival rates for non-Hodgkin’s lymphoma patients in first complete remission (CR) (83.2%), second or subsequent CR (74.1%), or first partial remission (PR) (66.7%) at the time of transplantation were significantly higher than those with no remission (35.7%) at the time of transplantation (first CR,P < .05; second or subsequent CR,P < .05; first PR,P < .05). The 5-year overall survival (OS) rates for breast cancer was 40.8%, and the disease-free survival rate was extremely low (8.8%). The 5-year OS rates for chemotherapy-sensitive and chemotherapy-resistant diseases at the time of transplantation were 32.7% and 35.7%, respectively, a difference that was not considered significant. The 5-year OS for germ cell tumor was 80.0%, and the disease-free survival rate was 77.9%. The rate of therapy-related death was 8.2%. The occurrence rate of secondary malignancy was 0.9%. Late-onset complications were observed in 4 cases (glomerulonephritis, interstitial pneumonitis, ulcerative colitis, and acute myelogenous leukemia). At 3.7%, the occurrence rate was not very high, but most complications of auto-PBSCT were life threatening and interfered with patients’ quality of life. A careful follow-up is required for at least 2 years after transplantation, because the mean occurrence time of late-onset complications is 16.7 months posttransplantation.

A Patient with Paroxysmal Nocturnal Hemoglobinuria in whom G-CSF Administration was Remarkably Effective against Recurrent Gastrointestinal Infections and Hemolytic Episodes Caused by Cellular Immunodeficiency

We report an elderly patient with paroxysmal nocturnal hemoglobinuria (PNH), having recurrent gastrointestinal infections and hemolytic episodes caused by cellular immunodeficiency due to a decreased number of T cells. On admission to our hospital, the patient had normal neutrophil count and function, but had decreased T cell count, decreased mitogenic reaction to PHA and ConA, and negative reaction to the tuberculin test. Thus, a cellular immunodeficiency state was suggested and postulated to be due to decreased T cell count caused by the loss of PNH clone of T cells. We previously reported that the administration of G-CSF to normal donors of allogeneic peripheral stem cell transplantation increases the lymphocyte count. Based on this experience, we administered G-CSF to this patient. This resulted in an increase in the T cell count, normalization of the mitogenic response to PHA and ConA, positive reaction to the tuberculin test and increases in the blood levels of Thl cytokines and Th2 cytokines, with an improvement in the gastrointestinal infections and hemolytic episodes. This suggested that G-CSF administration resulted in the recovery of cell-mediated immunity in the gastrointestinal mucosa. At 9 months after the start of G-CSF administration, these complications have not recurred. This is the first report of a patient of this type and suggests that G-CSF administration may be useful in the treatment of elderly PNH patients with cellular immunodeficiency.

C (H) OP refractory chronic lymphocytic leukemia patients in whom salvage chemotherapy chosen by evaluating multiple chemotherapeutic drug-resistant factors was remarkably effective

It is well known that the expression of anticancer drug-resistant factors is elevated in patients with primary refractory or relapsed chronic lymphocytic leukemia (CLL) who have been treated with chemotherapy. We report here two C(H)OP refractory patients with CLL in whom salvage chemotherapy chosen by evaluating anticancer drug-resistant factors (glutathione-S-transferase-Π [GST-Π], glycoprotein [GP]-170, multidrug resistance-associated protein [MRP], and lung resistance protein [LRP]) was remarkably effective. A 71-year-old male patient was refractory to induction therapy with cyclophosphamide, vincristine, and prednisone (COP), and his leukemic cells at diagnosis displayed overexpression of GST-Π and GP-170. A 74-year-old female patient’s condition had been stable; she had received ten courses of COP over 9 years. However, because systemic lymphadenopathies recurred, she was treated with chemotherapy consisting of cyclophosphamide, adriamycin, vincristine, and prednisone (CHOP) or dexamethasone, etoposide, ifosphamide, and carboplatin (DeVIC). However, she did not respond at all, and her leukemic cells at recurrence displayed overexpression of GST-Π. Therefore, we chose for these patients a salvage therapy consisting of dexamethasone and high-dose cytosine arabinoside (Ara C), to which neither GST-Π nor GP-170 show any drug resistance. In both patients, this salvage therapy proved effective.