chiniofon and Lung-Neoplasms

Research conducted by this laboratory over the past decade has demonstrated the high susceptibility of the fetus to lung tumor formation following in utero exposure of the resistant C57BL/6 and DBA/2N strains of mice to 3-methylcholanthrene (MC). In this review, we describe our more recent studies on the effects of MC and cotreatment with the lung tumor promoter, butylated hydroxytoluene (BHT), on lung tumor formation in the intermediately susceptible BALB/c strain of mice, and the determination of the potential carcinogenicity of the heterocyclic amine, 2-amino-3-methylimidazo[4,5-f]quinoline (IQ) in resistant mouse strains. BALB/c mice showed a similar incidence of lung tumors, both in terms of percentage of mice with tumors and number of tumors per mouse, as found in the resistant [D2 x B6D2F1]F2 mice. Ki-ras point mutations were found in 56% (20/36) of BALB/c lung lesions compared with an incidence of 79% in [D2 x B6D2F1]F2 mice. BALB/c lung lesions demonstrated a similar association of Ki-ras mutations with tumor stage. Interestingly, a strain-dependent difference was observed in the mutational spectrum, where 62% and 38% of the lesions in BALB/c mice exhibited G-->C and G-->T transversions, respectively, in contrast with the 16% and 84% incidences observed in [D2 x B6D2F1]F2 mice. BHT had no statistically significant effect on tumor incidence, multiplicity, or Ki-ras mutational spectrum in BALB/c mice treated in utero with MC, although a trend toward increased tumor multiplicity was observed. Finally, experiments initiated to assess the transplacental carcinogenicity of IQ in D2B6F1 mice demonstrated that 1 year after birth, no macroscopically or microscopically visible liver, lung, or colon tumors were found in the transplacentally treated offspring, nor was induction of Cyp1a1, Cyp1b1, or glutathione S-transferases (GSTs) in fetal lung and liver tissues observed. This implies that at least under these experimental conditions, IQ may not be an important transplacental carcinogen. Overall, these data demonstrate that mutagenic damage to Ki-ras is a critical early event mediating murine lung tumorigenesis in both sensitive and resistant strains. Strain-dependent differences in the Ki-ras mutational spectrum may be associated with their differential susceptibility to lung tumor initiation.

Topics: Adenocarcinoma; Adenoma; Animals; Aryl Hydrocarbon Hydroxylases; Butylated Hydroxytoluene; Carcinogens; Cytochrome P-450 CYP1B1; Disease Progression; Female; Fetus; Genes, ras; Genetic Predisposition to Disease; Hydroxyquinolines; Lung Neoplasms; Maternal Exposure; Methylcholanthrene; Mice; Mice, Inbred C57BL; Mice, Inbred DBA; Point Mutation; Pregnancy; Prenatal Exposure Delayed Effects; Species Specificity

The CDK/Rb/E2F pathway is commonly disrupted in lung cancer, and thus, it is predicted that blocking the E2F pathway would have therapeutic potential. To test this hypothesis, we have examined the activity of HLM006474 (a small molecule pan-E2F inhibitor) in lung cancer cell lines as a single agent and in combination with other compounds. HLM006474 reduces the viability of both SCLC and NSCLC lines with a biological IC50 that varies between 15 and 75 µM, but with no significant difference between the groups. Combination of HLM006474 with cisplatin and gemcitabine demonstrate little synergy; however, HLM006474 synergizes with paclitaxel. Surprisingly, we discovered that brief treatment of cells with HLM006474 led to an increase of E2F3 protein levels (due to de-repression of these promoter sites). Since paclitaxel sensitivity has been shown to correlate with E2F3 levels, we hypothesized that HLM006474 synergy with paclitaxel may be mediated by transient induction of E2F3. To test this, H1299 cells were depleted of E2F3a and E2F3b with siRNA and treated with paclitaxel. Assays of proliferation showed that both siRNAs significantly reduced paclitaxel sensitivity, as expected. Taken together, these results suggest that HLM006474 may have efficacy in lung cancer and may be useful in combination with taxanes.

Topics: Aminopyridines; Antineoplastic Combined Chemotherapy Protocols; Carcinoma, Non-Small-Cell Lung; Cell Line, Tumor; Cell Proliferation; Cell Survival; Cisplatin; Deoxycytidine; Drug Synergism; E2F3 Transcription Factor; Gemcitabine; Humans; Hydroxyquinolines; Inhibitory Concentration 50; Lung Neoplasms; Paclitaxel; RNA, Small Interfering; Small Cell Lung Carcinoma

Linomide, a quinoline-3-carboxamide, has the ability to inhibit the growth of prostatic cancer in vivo but not in vitro (T. Ichikawa et al., Cancer Res., 52: 3022-3028, 1992). The reason for this discrepancy is that linomide inhibits tumor growth not directly but indirectly in vivo via its ability to inhibit the angiogenic response induced within the growing prostatic cancer (J. Vukanovic, et al., Cancer Res., 53: 1833-1837, 1993). Tumor associated macrophages can stimulate angiogenesis via their ability to secrete various cytokines, particularly tumor necrosis factor alpha (TNF-alpha). Treatment of rats with linomide decreases significantly (P < 0.05), by more than 50%, the number of tumor associated macrophages within both locally invasive (i.e., from 20-40 to 10 macrophages/high power field) and highly metastatic primary prostatic cancers (i.e., from 60-70 to 15-37 macrophages/high power field). Monocytes/macrophages isolated from linomide treated rats had a decreased ability to secrete TNF-alpha when challenged in vitro with the bacterial endotoxin, lipopolysaccharide [i.e., 702 +/- 76 (SEM) ng of TNF-alpha/10(5) monocytes/macrophages from control versus 401 +/- 2 ng of TNF-alpha/10(5) monocytes/macrophages from linomide treated rats]. In addition, when rats were treated with linomide and than challenged with lipopolysaccharide in vivo, the resulting elevation in serum TNF-alpha was inhibited by approximately 50% (i.e., 4.56 +/- 1.8 ng/ml of TNF-alpha in control versus 2.9-2.2 ng/ml depending upon the dose of linomide). The ability of linomide to decrease monocyte/macrophage secretion of TNF-alpha is not immediate, however, since the secretion of TNF-alpha induced by lipopolysaccharide challenge of monocytes/macrophages isolated from untreated animals is not decreased by acute (i.e., < 4 h) linomide treatment in vitro. These results demonstrate that the ability of linomide to inhibit the secretion of TNF-alpha by monocytes/macrophages requires either additional time or host factors. To test if natural killer (NK) cells might be one of the additional host factors required for the in vivo abilities of linomide, prostatic cancer bearing rats were treated with appropriate antiserum to deplete NK cells and then tested for their response to linomide treatment. These studies demonstrated that the antitumor, antimetastatic, and antimacrophage effects of linomide were unaffected by NK cell depletion.(ABSTRACT TRUNCATED AT 400 WORDS)

Topics: Animals; Hydroxyquinolines; Killer Cells, Natural; Lipopolysaccharides; Lung Neoplasms; Macrophages; Male; Monocytes; Neovascularization, Pathologic; Prostatic Neoplasms; Rats; Rats, Inbred Strains; Tumor Necrosis Factor-alpha

Linomide (N-phenylmethyl-1,2-dihydro-4-hydroxyl-1-methyl-2-oxo-quinoline-3- carboxamide) is a quinoline 3-carboxamide which previously has been demonstrated to produce immunomodulator and antitumor effects when given in vivo. To test the possible antitumor effects of linomide against prostatic cancers, rats bearing five distinct Dunning R-3327 rat prostatic cancer sublines were treated daily with i.p. injections of linomide. These studies demonstrated that linomide has a reproducible antitumor effect against all of the prostatic cancers tested regardless of their growth rate, degree of morphologic differentiation, metastatic ability, or androgen responsiveness. This antitumor effect is observed only in vivo, not in vitro, and involves a cytotoxic response of the prostatic cancer cells. This cytotoxic response results in the retardation of the growth rate (i.e., increased tumor volume doubling time) of primary prostatic cancers and in metastatic lesions. Linomide's growth retardation is reversible, and thus continuous daily treatment with linomide is required for maximal antitumor response. Pretreatment of rats with linomide before tumor inoculation has no effect in addition to that produced by initiating linomide treatment at the time of tumor inoculation. No enhancement of either natural killer cell number or natural killer cell cytotoxic activity is induced by linomide treatment in the tumor-bearing rats. In addition, depletion of natural killer cell activity via injections of asialo-GM1 antiserum does not prevent the antitumor effects of linomide in vivo. Likewise, the antitumor effects of linomide are also produced in prostatic cancer-bearing athymic nude rats. These results suggest that the requirement for host involvement in the antitumor effects of linomide against rat prostatic cancers may involve both immune and nonimmune host mechanism(s) (e.g., antiangiogenesis).

Topics: Adjuvants, Immunologic; Animals; Antineoplastic Agents; Cell Division; Cell Line; Dose-Response Relationship, Drug; Drug Screening Assays, Antitumor; Hydroxyquinolines; Killer Cells, Natural; Lung Neoplasms; Male; Neoplasm Transplantation; Prostatic Neoplasms; Rats; Rats, Inbred Strains; Spleen; Tumor Cells, Cultured

In the current study we examine parameters affecting the metastasis of ocular tumors of in vivo derived B16F10 melanoma. In C57BL/6J beige (bg/bg) mice, with low NK activity, metastasis to the lungs was increased and survival time decreased. In C57BL/6J normal (+/+) mice treatment with PK136, a highly specific monoclonal anti-NK antibody (Ab), caused a depletion of NK cytotoxic activity, as demonstrated using a standard 51Cr release assay. In animals bearing ocular tumors, treatment with PK136 Ab resulted in significantly increased pulmonary metastasis and an altered pattern of metastasis. The effect of combined treatment protocols using LS2616 (linomide) and cyclophosphamide (Cy) was examined in enucleated and unenucleated animals. Treatment with LS2616 and Cy resulted in a significant decrease in mean pulmonary metastases (MPM), a decreased frequency of metastasis to the submandibular lymph nodes and an increase in mean survival time. In enucleated mice this combined treatment protocol resulted in apparent cures, the lowest MPM and the longest survival time observed. When tumor-bearing mice were treated with either silica, carrageenan or sublethal gamma irradiation, no effect on metastasis or survival was observed. This study demonstrates the importance of the NK cell as a primary effector cell for the control of metastasis from in vivo derived ocular B16F10 melanoma.

Topics: Adjuvants, Immunologic; Animals; Antibodies, Monoclonal; Cyclophosphamide; Eye Enucleation; Eye Neoplasms; Female; Hydroxyquinolines; Killer Cells, Natural; Lung Neoplasms; Male; Melanoma; Mice; Mice, Inbred C57BL

In experiments using cultured cells, LS2616 has been shown to decrease growth of primary tumors and pulmonary metastasis of murine melanoma. In the current study, we examine the efficacy of LS2616 for the prophylactic and therapeutic treatment of metastases from ocular and flank inoculations of the highly aggressive in vivo derived B16F10 melanoma in C57BL/6J mice. Experimental animals were treated with 160 mg/kg/day of this drug in drinking water, until they became moribund or died. When mice were pretreated for 7 days and inoculated subcutaneously (sc) or intracamerally (ic) with 10(5) in vivo derived B16F10 tumor cells, the mean number of pulmonary metastases was significantly reduced, and the incidence of pulmonary metastases decreased. In ocular experiments, when pretreatment with drug was combined with enucleation at day 7, the mean number of lung nodules was significantly reduced, the incidence of metastasis to the lung and lymph nodes decreased and survival increased. An apparent cure rate of 31% was observed. Treatment beginning on the day of enucleation (day 7) resulted in a reduction of pulmonary metastases, a decrease in metastasis to the lungs and lymph nodes and no change in survival. LS2616 did not alter tumorigenicity of either sc or ic inoculations. In an in vivo neutralization assay, spleen cells of mice treated for 7 days with LS2616 demonstrated an increase in cytostatic or cytotoxic activity when incubated with B16F10 melanoma cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Animals; Eye Enucleation; Eye Neoplasms; Female; Hydroxyquinolines; Lung Neoplasms; Male; Melanoma; Mice; Skin Neoplasms; Spleen; Tumor Cells, Cultured

Topics: Bone Neoplasms; Female; Humans; Hydroxyquinolines; Indium; Leukocytes; Lung Neoplasms; Organometallic Compounds; Oxyquinoline; Radionuclide Imaging

The carboxamide-quinoline LS 2616 is a novel immunomodulator augmenting natural killer (NK) cell activity and T-lymphocyte related effector functions. To investigate the possible usefulness of LS 2616 in immunotherapy of tumors, the effect of the substance on growth and metastasis of the B16-F10 melanoma in syngeneic C57BL/6 mice was investigated. Treatment with LS 2616 from the time of s.c. inoculation of B16-F10 cells significantly reduced tumor take. Continuous treatment of mice with LS 2616 initiated 4 days prior to i.v. injection of tumor cells reduced the number of pulmonary metastases by 85%. When treatment with LS 2616 was started 4 days after i.v. injection of tumor cells, a time when established tumor foci were readily detectable in the lungs, a significant reduction in the number of pulmonary metastases resulted. LS 2616 significantly reduced the number of spontaneous pulmonary metastases developing from a B16-F10 tumor growing in the footpad. When treatment with LS 2616 was initiated after the establishment of grossly visible spontaneous pulmonary metastases, no significant effect on the number of metastases was found after 2 weeks of treatment. However, combined treatment with a dose of cyclophosphamide which in itself was ineffective resulted in a statistically significant 70% reduction in the number of remaining pulmonary metastases. Injection of antibodies to asialomonoganglioside which strongly reduce NK cell activity in various organs was used as a probe for the involvement of NK cells in the effects of LS 2616 on the B16-F10 tumor. The therapeutic efficiency of LS 2616 on tumor take when given from the time of s.c. inoculation, on the number of i.v. induced pulmonary metastases when treatment was started before tumor cell injection, as well as the spontaneous development of pulmonary metastases during exposure to the substance was abrogated by simultaneous injection with antibodies to asialomonoganglioside. In contrast, the beneficial effects of LS 2616 on already established i.v. produced or spontaneous pulmonary metastases were unaltered in mice made NK cell deficient by injection of anti-asialomonoganglioside antibodies. In conclusion, LS 2616 has potent antitumor activities mediated by NK cells as well as non-NK cell related defense mechanisms.

Topics: Adjuvants, Immunologic; Animals; Antineoplastic Combined Chemotherapy Protocols; Cyclophosphamide; Hydroxyquinolines; Interleukin-2; Killer Cells, Natural; Lung Neoplasms; Melanoma; Mice; Mice, Inbred C57BL