Clinical significance of soluble interleukin-2 receptor as a putative systemic nutritional index in the elderly

The clinical significance of a slight increase of serum soluble interleukin-2 receptor (sIL2R) concentration in the stable elderly was investigated. Thirty-five residents of nursing homes with physical impairment as a sequel to cerebral infarctions, without any inflammatory condition, anodyne or immunological treatment, were divided into two groups: 24 without overt or suspected malignancy (NC) and 11 with a history of malignancy (CA). Serological screening with measurement of sIL2 R concentrations was performed and numbers of lymphocytes with CD4, CD8 markers were determined. The NC group was divided into controls (n = 15, sIL2R < = 883 U/mL) and subjects demonstrating elevation (n = 9, NH), as in a previous study. Differences were found in serum concentrations of albumin, blood urea nitrogen, total cholesterol concentration, Pettigrew's prognostic nutritional index (PNI), as well as the ADL score, but not age or sex between NH and controls. Factor analysis in NC revealed serum creatinine and blood urea nitrogen concentrations to correlate positively, and serum albumin, total cholesterol concentrations, ADL score, PNI to correlate negatively to sIL2R. Differences were found in sIL2R, albumin, total protein, total cholesterol, beta-lipoprotein, PNI between CA and controls, but correlations were not found in CA. Survival rate of controls over twenty-four months was better than that of NH, but not of CA. Our results suggest that a slight increase of concentration of sIL2R is related to subclinical systemic deterioration, especially with regard to nutrition, with a plausible connection to prognosis of the stable elderly without malignancy.     

Frequent mutations of the rat beta-catenin gene in colon cancers induced by methylazoxymethanol acetate plus 1-hydroxyanthraquinone

Recent evidence suggests that the beta-catenin gene (CTNNB1) acts as an oncogene, and some human colon tumors with an intact APC gene have activating mutations in CTNNB1. In this study, mutations in the region corresponding to N-terminal phosphorylation sites (codons 1-51) of the rat Ctnnb1 gene were investigated in 20 colon tumors associated with ulcerative colitis and induced with methylazoxymethanol acetate and 1-hydroxyanthraquinone. Ninety percent (18 of 20) of the tumors induced in male F344 rats harbored mutations, which were detected in three of four adenomas (75%) and 15 of 16 adenocarcinomas (94%). Of 18 total missense mutations, 13 (72%) were G-->A transitions at position 101, three were G-->A transitions at position 94, and two were C-->T transitions at position 122, resulting in the amino acid substitutions Gly34-->Glu, Asp32-->Asn, and Thr41-->Ile, respectively. Although there were no mutations in the Apc gene, as we previously reported in the same tumor samples, the results obtained in this study strongly implicate the Apc-beta-catenin-T-cell factor (Tcf) signaling pathway in methylazoxymethanol acetate, 1-hydroxyanthraquinone-induced colon carcinogenesis.     

The Src family tyrosine kinase is involved in Rho-dependent activation of c-Jun N-terminal kinase by Galpha12.

Gt12, a member of alpha subunit of heterotrimeric G protein G12 subfamily, has been shown to stimulate c-Jun N-terminal kinase (JNK) activity through the low molecular weight GTP-binding proteins Ras, Rac, and Cdc42. In this study using the transient expression of a constitutively activated mutant of Galpha12 (Galpha12Q229L) in human embryonic kidney (HEK) 293 cells, we found that Rho and Src family kinase are also involved in the Galpha12-induced activation of JNK. The activation of JNK by Galpha12Q229L was inhibited by dominant-negative RhoA(T19N), and botulinum C3 exoenzyme which specifically inactivates Rho. In addition, the expression of activated RhoA(G14V) elevated JNK activity in HEK 293 cells. The Galpha12Q229L-stimulated activation of JNK was blocked by a specific inhibitor of protein tyrosine kinases (PP2), and C-terminal Src kinase (Csk). Moreover, we observed that Galpha12Q229L stimulated Src family kinase activity and v-Src induced JNK activation. Interestingly, the v-Src-induced activation of JNK was inhibited by dominant-negative RhoA(T19N). In contrast, Csk did not inhibit the JNK activation by activated RhoA(G14V). These results suggest that Rho and Src family kinase are required for the Galpha12-induced JNK activation, and that Src family kinase acts upstream of Rho activation in the JNK pathway.     

Difference in Target Organs in Carcinogenesis with a Heterocyclic Amine, 2-Amino-3,4-dimethylimidazo[4,5-f]quinoline, in Different Strains of Mice

2-Amino-3,4-dimethylimidazo[4,5- f ]quinoline (MeIQ) induces cancers in the forestomach and liver, but not in the colon, of CDF1 male and female mice, which are thought to be resistant to induction of colon cancer by 1,2-dimethylhydrazine. In this study, we examined the carcinogenicity of MeIQ in C57BL/6N female mice, which are susceptible to 1,2-dimethylhydrazine. This strain of mice developed carcinomas of the cecum, colon and liver, but not the forestomach, when given a diet containing 300 ppm of MeIQ. This fact indicates that the target organs of a chemical carcinogen change depending on the strain of a given animal species.     

Strain differences of rats in the susceptibility to aberrant crypt foci formation by 2-amino-1-methyl-6-phenylimidazo- [4,5-b]pyridine: no implication of Apc and Pla2g2a genetic polymorphisms in differential susceptibility.

2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), the most abundant mutagenic heterocyclic amine contained in cooked food, induces colon tumors in F344 male rats when administered orally. In the present study, PhIP was introduced to various rat strains, and susceptibility to the induction of aberrant crypt foci (ACFs) was analyzed as a biomarker for colon carcinogenesis. BUF/Nac rats were highly susceptible, giving rise to 12.2 +/- 1.7 ACFs per rat. F344 rats were intermediate and ACI/N rats were resistant, giving 3.5 +/- 1.8 and 0.9 +/- 0.7 ACFs per rat, respectively. In spite of this, the extent of DNA damage by PhIP in F344, in terms of the level of PhIP-DNA adducts, was significantly lower than that in ACI/N. The differences in formation of ACFs could be, in some part, implicated in the differential susceptibility to colon carcinogenesis induced by PhIP, especially in a step later than adduct formation. In an attempt to determine the genetic factors implicated in the susceptibility to formation of ACFs, a possible involvement of the adenomatous polyposis gene (Apc) and its modifier secretory phospholipase A2 (Pla2g2a) was analyzed. No genetic polymorphisms in either Apc or Pla2g2a showed a significant correlation to susceptibility to formation of ACFs among rat strains.     

Binding pockets of the beta(1)- and beta(2)-adrenergic receptors for subtype-selective agonists.

We examined the subtype-selective binding site of the beta-adrenergic receptors (betaARs). The beta(1)/beta(2)-chimeric receptors showed the importance of the second and seventh transmembrane domains (TM2 and TM7) of the beta(2)AR for the binding of the beta(2)-selective agonists such as formoterol and procaterol. Alanine-substituted mutants of TM7 of the beta(2)AR showed that Tyr(308,) located at the top of TM7, mainly contributed to beta(2) selectivity. However, Tyr(308) interacted with formoterol and procaterol in two different ways. The results of Ala- and Phe-substituted mutants indicated that the phenyl group of Tyr(308) interacted with the phenyl group in the N-substituent of formoterol (hydrophobic interaction), and the hydroxyl group of Tyr(308) interacted with the protonated amine of procaterol (hydrophilic interaction). In contrast to beta(2)AR, TM2 is a major determinant that beta(1)-selective agonists such as denopamine and T-0509 bound the beta(1)AR with high affinity. Three amino acids (Leu(110), Thr(117), and Val(120)) in TM2 of the beta(1)AR were identified as major determinants for beta(1)-selective binding of these agonists. Three-dimensional models built on the basis of the predicted structure of rhodopsin showed that Tyr(308) of the beta(2)AR covered the binding pocket formed by TM2 and TM7 from the upper side, and Thr(117) of the beta(1)AR located in the middle of the binding pocket to provide a hydrogen bonding for the beta(1)-selective agonists. These data indicate that TM2 and TM7 of the betaAR formed the binding pocket that binds the betaAR subtype-selective agonists with high affinity.     

Demonstration of ras and p53 Gene Mutations in Carcinomas in the Forestomach and Intestine and Soft Tissue Sarcomas Induced by N-Methyl-N-nitrosourea in the Rat

The presence of ras family and p53 gene mutations in rat forestomach, intestine and liver tumors and soft tissue sarcomas induced by N methyl- N -nitrosourea (MNU) was examined using polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) followed by direct sequencing analysis. In the forestomach squamous cell carcinomas (SCC), Ha- ros and p53 mutations were detected in 2 (40%) and 4 (80%) of 5 cases, respectively. The figures for Ki- ras and p53 gene mutations in adenocarcinomas of the large and small intestines were 3 (18.8%) and 5 (31.3%) of 16 cases. Soft tissue sarcomas in different sites were found to have mutations of Ki- ras in 7 (23.3%)and of p53 in 9 (30%) of 30 cases. One forestomach SCC and 2 soft tissue sarcomas had double p53 mutations in different exons. Single cases of forestomach SCC and intestinal adenocarcinoma had mutations in both Ki- ras and p53 genes. No mutations were found in counterpart benign tumors or hepatocellular adenomas. The p53 mutation spectrum revealed preferential clustering within exon 8 for the forestomach SCCs, and exons 5 and 8 for the intestinal adenocarcinomas, whereas the distribution was evenly spread through exons 5 to 8 in soft tissue sarcomas. All the detected ras or p53 mutations were G:C to A:T transitions. These results indicate firstly that specific Ki- ras , Ha- ras and p53 gene mutations in MNU-induced lesions are related to particular alkylation sites (G:C to A:T transitions) and secondly, although not essential, Ki- ras , Ha- ras or p53 gene mutations may be involved in the progression stage of forestomach, intestine and soft tissue neoplasms induced by MNU.     

A phase II trial of combination of CPT-11 and cisplatin for advanced non-small-cell lung cancer. CPT-11 Lung Cancer Study Group.

A phase I trial of the combination of irinotecan (CPT-11) with cisplatin in advanced non-small cell lung cancer (NSCLC) showed a very promising response rate of 54% in previously untreated NSCLC patients. This study was conducted to confirm the activity and toxicities of CPT-11 and cisplatin combination for previously untreated NSCLC in a multi-institutional phase II study. Seventy patients with stage IIIB or IV NSCLC received CPT-11 60 mg m(-2) intravenously (i.v.) on days 1, 8 and 15, and cisplatin 80 mg m(-2) (i.v.) on day 1 every 4 weeks. Assessments were made of response, survival and toxicities. Sixty-nine were eligible, and evaluable for toxicities and survival, and 64 patients evaluable for response. Thirty-three patients (52%; 95% confidence interval 39-64%) achieved an objective response, with one complete response (2%) and 32 partial responses (50%). The median duration of response was 19 weeks and the overall median survival time was 44 weeks. The 1-year survival rate was 33%. The major toxic effects were leucopenia and diarrhoea. Grade 3 or 4 leucopenia, neutropenia, and diarrhoea occurred in 32 patients (46%), 53 patients (80%), and 13 patients (19%) respectively. A combination of CPT-11 and cisplatin is very effective against non-small-cell lung cancer with acceptable toxicities.     

Changes in folate concentration in Yoshida sarcoma after administration of leucovorin or cisplatin

Both leucovorin (LV) and cisplatin (cis-dichlorodiammine platinum II, CDDP) act as modulators of 5-fluorouracil (5-FUra) by increasing the intracellular concentration of reduced folate. We measured intracellular folate levels following the administration of LV or cisplatin in tumor-bearing rats to determine the optimal schedules for their use as 5-FUra modulators. Donryu rats were inoculated with Yoshida sarcoma cells on the right flank. Seven days after tumor inoculation, the animals were injected with LV or CDDP. The kinetic and dose-related changes in intracellular folate concentration were analyzed by means of a binding assay. Folate levels in the tumor tissues were significantly higher than baseline 1 and 2 h after administration of LV and remained significantly high until 8 h after administration. Folate levels in the tumor tissues were significantly higher than baseline 1 and 2 h after cisplatin administration, then decreased to a rather low level 8 h after, and to a significantly lower level than baseline 24 h after administration. The folate levels in the tumor tissue increased in proportion to the dose of LV, but did not increase when the dose of cisplatin was increased from 1 mg/kg to 8 mg/kg. Repeat high-dose administration of LV and repeat low-dose administration of cisplatin are advocated when they are used as modulators of 5-FUra.