Anticancer chemosensitivity profile of freshly separated human pancreatic cancer cells assessed by DNA synthesis inhibition assay

The chemosensitivity of 49 freshly separated human pancreatic cancers to seven kinds of anticancer agents were assessed by a DNA synthesis (³H-thymidine incorporation) inhibition assay. DNA synthesis is higher in involved lymph nodes (n=7), malignant effusion (n=15), liver metastasis (n=7), primary cancer (n=15), and skin metastasis (n=5). Chemosensitivity assay demonstrates that etoposide, 4-epirubicin, carboquone, and 5-fluorouracil are more effective than cisplatin, mitomycin-C, and Adriamycin. In general, metastatic lesions of pancreatic cancer tend to show higher chemosensitivity than primary lesions. Pathological analysis demonstrates that small primary pancreatic cancers tend to be more responsive than large primary cancers, and primary pancreatic cancers with no regional lymph node involvement also tend to be more responsive than those with nodal involvement. No significant differences are seen in terms of tumor spread, vascular involvement, sex of patient, and histological type. When chemosensitivity assay is not available, the results of the present study may be beneficial to choose the regimens. © 1994 Wiley-Liss, Inc.     

The involvement of mitochondrial apoptotic pathway in eugenol-induced cell death in human glioblastoma cells

Eugenol, a natural phenolic constituent of clove oil, has a wide range of applications in medicine as a local antiseptic and anesthetic. However, the effect of eugenol on human glioblastoma is unclear. This study examined whether eugenol elevated intracellular free Ca²⁺ levels ([Ca²⁺]_i) and induced apoptosis in DBTRG-05MG human glioblastoma cells. Eugenol evoked [Ca²⁺]_i rises which were reduced by removing extracellular Ca²⁺. Eugenol-induced [Ca²⁺]_i rises were not altered by store-operated Ca²⁺ channel blockers but were inhibited by the PKC inhibitor GF109203X and the transient receptor potential channel melastatin 8 (TRPM8) antagonist capsazepine. In Ca²⁺-free medium, pretreatment with the endoplasmic reticulum Ca²⁺ pump inhibitor thapsigargin (TG) or 2,5-di-tert-butylhydroquinone (BHQ) abolished eugenol-induced [Ca²⁺]_i rises. The phospholipase C (PLC) inhibitor U73122 significantly inhibited eugenol-induced [Ca²⁺]_i rises. Eugenol killed cells which were not reversed by prechelating cytosolic Ca²⁺ with 1,2-bis(2-aminophenoxy) ethane-N,N,N′,N′-tetraacetic acid-acetoxymethyl ester (BAPTA-AM). Eugenol induced apoptosis through increasing reactive oxygen species (ROS) production, decreasing mitochondrial membrane potential, releasing cytochrome c and activating caspase-9/caspase-3. Together, in DBTRG-05MG cells, eugenol evoked [Ca²⁺]_i rises by inducing PLC-dependent release of Ca²⁺ from the endoplasmic reticulum and caused Ca²⁺ influx possibly through TRPM8 or PKC-sensitive channels. Furthermore, eugenol induced the mitochondrial apoptotic pathway.     

The role of organic anion‐transporting polypeptides and formulation in the clearance and distribution of a novel Nav1.7 channel blocker

PF‐06456384 is an extremely potent and selective blocker of the Na_v1.7 sodium channel designed as a potential intravenous (i.v.) analgesic targeting high potency and rapid clearance to minimize the potential for residual effects following the end of infusion. In our previous experience targeting oral molecules, the requirement to obtain potent, Na_v1.7 selective molecules led to a focus on acidic, amphipilic compounds cleared primarily by organic anion‐transporting polypeptide mediated hepatic uptake and subsequent biliary excretion. However, the physicochemical properties of the i.v. lead matter were substantially different, moving from acidic, amphiphilic chemical space to zwitterions as well as substantially increasing molecular weight. This report describes the continued relevance of organic anion‐transporting polypeptide driven hepatic uptake in this physicochemical space and highlights an apparent impact of the formulation excipient Solutol on the clearance and distribution of PF‐06456384.     

Oral administration of OK-432 (picibanil). (8th report) clinical application: its immunomodulatory effects on the patients with gastrointestinal cancers

A streptococcal preparation, OK-432 at a dose of 5 KE was orally administered to the patients with gastric or colorectal cancer for 7 approximately 14 days before operation, and its immunomodulatory effects on peripheral blood lymphocytes (PBL), regional lymph node lymphocytes (RLNL) and tumor infiltrating lymphocytes (TIL) were assessed. OK-432 treated group included 5 gastric and 6 colorectal cancers, and control group included 6 gastric and 8 colorectal cancers. After oral administration of OK-432 the proportion of Leu 7+ and Leu 11+ cells in PBL increased, and NK cell activity of PBL also was augmented. The proportion of OKT8+ cells increased in PBL and those of OKT3+ cells and OKT8+ cells decreased in RLNL after oral administration of OK-432. The responsiveness of TIL to autologous tumor extracts in the presence of interleukin-2 was enhanced in oral OK-432 group. These results indicate that oral OK-432 affects on NK and T cells and augments the antitumor immunity of the patients with gastrointestinal cancer.     

Ripe areca nut extract induces G1 phase arrests and senescence-associated phenotypes in normal human oral keratinocyte

Around 200-600 million Asians chew areca (also called betel), which contains a mixture of areca nut and other ingredients. Epidemiological evidences indicated that areca use is tightly linked to oral carcinogenesis. This study investigated the effects of ripe areca nut extract (ANE) on cultured normal human oral keratinocyte (NHOK). Acute subtoxic ANE treatment inhibited DNA synthesis and induced cell cycle arrest at G1 phase in early passage (< 4th passage) cells. This was accompanied by a slight increase in the sub-G1 cellular fraction. O6-Methylguanine-DNA methyltransferase (MGMT), Hsp27 and p38MAPK was upregulated. p16 and p21 were remarkably upregulated early and declined afterwards. In contrast, the increase of dephosphorylated Rb seemed to be secondary to the episodes of p16 and p21 upregulation. To simulate the chronic areca exposure in vivo, constant ANE treatment in serial NHOK culture was performed. It resulted in a significant decrease in the population doubling, increase in senescence-associated beta-galactosidase (SA-beta-Gal) and decrease in cell proliferation in NHOK of late passages (> or = 4th passage). Induction of senescence-associated phenotypes, G2/M accumulation and genomic instability following long-term ANE treatment were also observed in a low-grade oral carcinoma cell. ANE-treated NHOK also had a higher nuclear factor-kappaB (NF-kappaB) fraction and a lower cytosolic IkappaBalpha level relative to the control in late passages. Moreover, electrophoretic mobility shift assay (EMSA) indicated that ANE treatment shifted the NF-kappaB complex from high mobility position to lower mobility position in late-passaged NHOK. ANE treatment also upregulated IL-6 and cyclooxygenase-2 (COX-2) mRNA expressions in late-passaged NHOK. In summary, our findings suggest that ANE induces the cell cycle arrest at G1/S phase and the occurrence of senescence-associated phenotypes of NHOK. The upregulation of p38MAPK, p16, p21, NF-kappaB, IL-6 and COX-2 are likely to participate in the control of these impacts.     

Interleukin-4 receptor-targeted liposomal doxorubicin as a model for enhancing cellular uptake and antitumor efficacy in murine colorectal cancer

Our previous studies showed that colorectal tumor has high interleukin-4 receptor α (IL-4Rα) expression, whereas adjacent normal tissue has low or no IL-4Rα expression. We also observed that human atherosclerotic plaque-specific peptide-1 (AP1) can specifically target to IL-4Rα. In this study, we investigated the therapeutic efficacy and systemic toxicity of AP1-conjuagted liposomal doxorubicin. AP1 bound more strongly to and was more efficiently internalized into IL-4Rα-overexpressing CT26 cells than CT26 control cells. Selective cytotoxicity experiment revealed that AP1-conjugated liposomal doxorubicin preferentially killed IL-4Rα-overexpressing CT26 cells. AP1-conjugated liposomal doxorubicin administered intravenously into mice produced significant inhibition of tumor growth and showed decreased cardiotoxicity of doxorubicin. These results indicated that AP1-conjugated liposomal doxorubicin has a potent and selective anticancer potential against IL-4Rα-overexpressing colorectal cancer cells, thus providing a model for targeted anticancer therapy.