Resistant Solid Tumors Research Articles

Sarcomelicope alkaloids as leads for the discovery of new antitumor acronycine derivatives

The acridone alkaloid acronycine first isolated from Acronychiabaueri Schott (Rutaceae) in 1948, was later shown to exhibit a promising activity against a broad spectrum of solid tumors. Nevertheless, clinical trials only gave poor results, probably due to the moderate potency and low water solubility of this alkaloid. Early studies on structure-activity relationships in the series concluded that the 1,2-double bond was an essential structural requirement to observe cytotoxic activity. It is the reason why the isolation in our laboratory of the unstable acronycine epoxide from several New-Caledonian Sarcomelicope species led to the hypothesis of bioactivation of acronycine by transformation of the 1,2-double bond into the corresponding oxirane in vivo. Consequently, there was interest in the search for acronycine derivatives modified in the pyran ring and having improved stability, but a similar reactivity toward nucleophilic agents as acronycine epoxide. Accordingly, we synthesized a series of cis- and trans-1,2-dihydroxy-1,2-dihydroacronycine diesters which exhibited interesting antitumor properties with a broadened spectrum of activity and increased potency when compared with acronycine. (±)-Cis-1,2-diacetoxy-1,2-dihydroacronycine was of particular interest, due to its marked activity in vivo against the resistant solid tumor C 38 colon carcinoma. The demonstration that acronycine should interact with DNA by some noncovalent process able to stabilize the double helix against thermal denaturation prompted us to develop benzo[b]acronycine analogues possessing an additional aromatic ring linearly fused on the natural alkaloid basic skeleton. When tested against a panel of cancer cell lines in vitro, cis-1,2-dihydroxy-1,2-dihydrobenzo[b]acronycine diesters exhibited cytotoxic activities within the same range of potency as the most active drugs currently used in cancer chemotherapy. In vivo, cis-1,2-diacetoxy-1,2-dihydrobenzo[b]acronycine (S23906-1), selected for further preclinical development, demonstated a marked antitumor activity in human orthotopic models of lung, ovarian and colon cancers xenografted in nude mice.

The influence of cytotoxicity of macromolecules and of VEGF gene modulated vascular permeability on the enhanced permeability and retention effect in resistant solid tumors.

To study the influence of cytotoxicity of macromolecules, VEGF gene expression, and vascular permeability on the enhanced permeability and retention (EPR) effect. Mice bearing xenografts of A2780 multidrug resistant human ovarian carcinoma were treated by free doxorubicin (DOX) and N-(2-hydroxypropyl)methacrylamide (HPMA) copolymer-bound DOX (P(GFLG)-DOX), Texas Red (P-TR), and FITC (P-FITC). Antitumor activity, drug distribution in tumor, vascular permeability, VEGF gene expression, and DNA fragmentation were studied. The accumulation of free DOX led to the VEGF gene overexpression and increased the vascular permeability, which in turn enhanced the drug accumulation in the same location. This positive feedback loop led to a highly inhomogeneous distribution of the drug within the tumor. In contrast, P(GFLG)-DOX down-regulated the VEGF gene and decreased vascular permeability. This negative feedback seemed to prevent additional drug accumulation in dead necrotic tissue, resulting in a more uniform drug distribution and enhanced the antitumor activity P(GFLG)-DOX. The EPR effect significantly differed for macromolecules containing DOX when compared to macromolecules without drug. The cytotoxicity of P(GFLG)-DOX amplified the EPR effect, led to a more homogenous distribution of the drug, increased the average drug concentration in tumor and augmented its efficacy.

P-Glycoprotein Expression and Multidrug Resistance in Cutaneous T-cell Lymphoma

Advanced-stage cutaneous T-cell lymphoma (CTCL) is generally resistant to standard chemotherapy. Because P-glycoproteiri (P-gp) has beeti detected in other types of resistant solid tumors, leukemias, and lymphomas, we analyzed P-gp expression in CTCL. Twenty-seven patients with CTCL and circulating Sezary cells in the peripheral blood as observed on a peripheral smear treated at the Yale Photopheresis Center between 1987 and 1993 were identified. Twenty-five of these patients had skin biopsies evaluated for expression of P-gp using JSB-I (Accurate Chemical), MRK-16 (gift of T. Tsuruo), and UIC-2 (gift of E. Metchner). P-gp expression was considered present if immunoreactivity was noted with two of the three antibodies. Eighteen of 25 patients (72%) evaluated exhibited expression. The patients were treated with vairiaus combinations of drugs consisting of topical and systemic steroids, electron beam therapy. psoralens in combination with UV light A (PUVA), systemic chemotherapy, and photophersis before testing the tissue for P-gp expression. Treatment with systemic chemotherapy in P-gp-positive patients produced responses in 3 and no responses in II patints (4 were lost to follow-up). Seven patients did not express P-gp: One patiem responded to treatment. five did not respond, and one patient was lost to follow -up. These results demonstrate that P-gp is frequently expressed in CTCL. P-gp expression in our study was not a useful predictor of drug resistance.

Preclinical efficacy of thioxanthone SR271425 against transplanted solid tumors of mouse and human origin.

A highly active and broadly active thioxanthone has been identified: N-[[1-[[2-(Diethylamino)ethyl]amino]-7-methoxy-9-oxo-9H-thioxanthen++ +-4-yl] methylformamide (SR271425, BCN326862, WIN71425). In preclinical testing against a variety of subcutaneously growing solid tumors, the following %T/C and Log10 tumor cell kill (LK) values were obtained: Panc-03 T/C = 0, 5/5 cures; Colon-38 (adv. stage) T/C = 0, 3/5 cures, 4.9 LK; Mam-16/C T/C = 0, 3.5 LK; Mam-17/0 T/C = 0, 2.8 LK; Colon-26 T/C = 0, 1/5 cures, 3.2 LK; Colon-51 T/C = 0, 2.7 LK; Panc-02 T/C = 0, 3.1 LK; B16 Melanoma T/C = 13%, 4.0 LK; Squamous Lung-LC12 (adv. stage) T/C = 14%, 4.9 LK; BG-1 human ovarian T/C = 16%, 1.3 LK; WSU-Brl human breast T/C = 25%, 0.8 LK. The agent was modestly active against doxorubicin (Adr)-resistant solid tumors: Mam-17/AdrT/C =23%, 0.8 LK; and Mam-16/C/Adr T/C = 25%, 1.0 LK, but retained substantial activity against a taxol-resistant tumor: Mam-16/C/taxol T/C = 3%, 2.4 LK. SR271425 was highly active against IV implanted leukemias, L1210 6.3 LK and AML1498 5.3 LK. The agent was equally active both by the IV and oral routes of administration, although requiring approximately 30% higher dose by the oral route. Based on its preclinical antitumor profile, it may be appropriate to evaluate SR271425 in clinical trials.

Pilot study of multiple chemotherapy resistance modulators plus epirubicin in the treatment of resistant malignancies.

We studied the toxicity and efficacy of adding to epirubicin five resistance modulators in the treatment of resistant solid tumors. Additional drugs were added in successive cohorts of patients, such that cohort 1 patients received two drugs along with their epirubicin, while cohort 4 patients received five modulators along with their epirubicin. Metronidazole, tamoxifen (cohort 1), dipyridamole (cohort 2), ketoconazole (cohort 3) and cyclosporin (cohort 4) were administered with epirubicin. A total of 22 patients were treated. Nausea and vomiting was usually mild to moderate. There was an unexpectedly high incidence of possible cardiac toxicity associated with treatment, although in some patients it was uncertain whether or not observed cardiac events were related to treatment. Granulocytopenia was significant in all four cohorts, but it was unclear whether it was increased by the modulators. There were two febrile neutropenic events in cohorts 1 and 2 successfully treated with antibiotics, and three septic deaths (one in each of cohorts 1, 2 and 4). It was elected to discontinue enrollment on the study prematurely in light of cardiac and other toxicity seen in the first two patients accrued in cohort 4. A single response was observed. While this approach is feasible, the observed toxicity and the difficulty patients experienced in ingesting the large number of prescribed pills will make further exploration of this approach difficult.

Concurrent use of multiple chemotherapy resistance modulators with etoposide in patients with resistant malignancies

Since chemotherapy resistance is probably multifactorial, we studied the toxicity and efficacy of adding to etoposide in sequence 5 resistance modulators in the treatment of resistant solid tumors. In cohort 1, metronidazole and ketoconazole were given with i.v. etoposide 100 mg/m(2)/day x 5 days. Because of excessive toxicity, cohort 2 received just metronidazole with etoposide, and metronidazole doses were reduced. Subsequent patient cohorts had the following drugs added to etoposide plus metronidazole: ketoconazole (cohort 3), dipyridamole (cohort 4), tamoxifen [cohort 5 (with etoposide 75 mg/m(2)/day) and 6 (with etoposide 60 mg/m(2)/day)], and cyclosporin (cohort 7). Hence, cohort 7 received daily x 5 i.v. etoposide 60 mg/m(2)/day plus 5 resistance modulators. Forty patients were treated, of whom 38 were evaluable for toxicity. Metronidazole resulted in augmentation of both central neurotoxicity and peripheral neuropathy. Sequential addition of each of dipyridamole, tamoxifen, and cyclosporin appeared to increase hematological toxicity. Some patients also experienced reversible hepatic and renal toxicity. Partial responses were seen in adrenocortical and small cell lung cancers, and minor responses with symptomatic improvement were seen in adrenocortical, small cell lung, non-small cell lung and colorectal carcinomas. Further evaluation of this approach may be warranted in patients with minimal prior chemotherapy exposure.

Hydroxyurea as a modulator of multidrug resistance in resistant solid tumor

We enrolled 11 consecutive pre-treated resistant advanced cancer patients to receive hydroxyurea (HU) (as modulator of MDR) 10 mg/kg/day (d) p.o. d 1-14 in association with DXR (d 15) alone or in combination with VDS (d 15) or VP16 (d 15-17) in presence, respectively, of soft tissue sarcoma, breast carcinoma, lung and gastric carcinoma. We obtained a stabilization of disease (NC) in 62.5% of patients, with a mean duration of 6 months. The mean survival was 12.2+ months for NC and 6 months for progressive disease (PD). No severe or unexpected adverse events were reported over 34 cycles administered; the most frequently recorded side effects were haematological and gastrointestinal toxicity. It seems that at the dosage we used, HU is poorly active in overcoming MDR; further studies with larger number of patients and different dosage are needed.

Suicide Gene Therapy for Intrinsically Drug Resistant Solid Tumors

The failure of available anticancer drugs to cure the common human solid tumors is thought to be caused by their poor selective toxicity. As demonstrated herein, suicide gene therapy offers the potential to improve selective toxicity.

Phase I Study of Retelliptine Dihydrochloride (SR 95325 B) Using a Single Two-Hour Intravenous Infusion Schedule

Retelliptine dihydrochloride (SR 95325 B, NSC D-626717-W) is an ellipticine derivative having a very high level of antitumor activity in resistant murine solid tumor models. We studied in a Phase I trial escalating doses of retelliptine using a single 2-hour IV infusion schedule. Data from other Phase I studies allowed a starting dose of 80 mg/m2 and a rapid dose escalation. Included were 15 patients (M/F = 13/2) with a median age of 55 (range: 17-72). There were 22 courses delivered at the following dose levels: 80, 180, 700, 900, 1,200, and 1,500 mg/m2. Primary tumor types were kidney (6 patients), colon (3 patients), pancreas (2 patients), and others (4 patients). Mild dose-related visual troubles (blurring, accommodation troubles, oculomotor paresis) occurred in 9/11 patients starting from 700 mg/m2. Asymptomatic EKG anomalies, including significant prolongation of PR and QRS intervals occurred at 1500 mg/m2 (in 3/3 patients) marking the maximum tolerated dose. Both visual and EKG anomalies were spontaneously reversible few minutes to few hours after the end of infusion. Other possible drug-related toxicity occurred sporadically such as somnolence, bronchospasm, dry mouth, and vomiting (2 patients each). There were no significant laboratory anomalies. Neither drug-related deaths nor objective complete or partial responses were observed. The recommended dose for Phase II trial using the 2-hour intravenous infusion schedule is 1,200 mg/m2.

Sinusitis in Bone Marrow Transplantation

Bone marrow transplantation has become a beneficial and curative technique used in treatment of patients with different hematologic conditions. It has become widely used at our institution for hematologic malignancies and certain resistant solid tumors. However, this treatment can result in immunosuppression, with an increased chance of infection. The purpose of this study was to review the causes of infections and determine the number of patients diagnosed with sinusitis. In the retrospective study, we evaluated the cases of bone marrow transplant patients for incidence and cause of fever. Sixty-eight percent of patients had fever after transplant; of these, 59% had fever of unknown origin. Only 1% of the patients with fever were diagnosed with sinusitis. In the evaluation of fever, sinusitis was not usually suspected and therefore was not included in the differential diagnosis. With such a high percentage of fever of unknown origin in this growing patient population, appropriate pretreatment evaluation of each case to rule out sinusitis should be considered.

PHASE-I HUMAN CLINICAL-TRIAL OF ONCONASE(R) (P-30 PROTEIN) ADMINISTERED INTRAVENOUSLY ON A WEEKLY SCHEDULE IN CANCER-PATIENTS WITH SOLID TUMORS

ONCONASE(R) (ONC), previously known as P-30 Protein, is a novel amphibian protein isolated from Rana pipiens eggs/early embryos (1) which demonstrates cytostatic and cytotoxic activity against several human tumor cell lines in vitro, as well as anti-tumor activity in vivo. Animal toxicology studies in rats and dogs revealed dose-dependent weight loss, some skeletal muscle and myocardial degenerative changes, a decrease in albumin and bilirubin levels in rats, and a dose-related elevation of serum transaminases and alkaline phosphatase in both species. A human weekly schedule Phase I study of intravenous bolus ONC was initiated, with dose levels ranging from 60 mug/m2 (anticipated human dose) to 960 mug/m2. Five patients were treated per dose level, without dose escalations within the same patients. Dose levels were doubled in new groups of patients with a variety of relapsing and resistant tumors. A correlation was noted between the dose level and the number of doses (cumulative effect), and the toxicities observed. The dose limiting toxicity was renal as manifested by proteinuria with edema, +/- azotemia and fatigue. Other side effects included flushing, myalgias, transient dizziness, and decreased appetite. Two patients, one at 480 mug/m2 and another at 960 mug/m2 levels, developed reversible hypotensive reactions preceded by flushing. The maximum tolerated dose (MTD) appears to be 960 mug/m2. Incidental findings included some objective responses in non-small cell lung, esophageal, and colorectal carcinomas. It has been concluded that ONCONASE was well tolerated by the majority of patients, demonstrated a consistent and reversible clinical toxicity patterns, did not induce most of the toxicities (such as, e.g., myelosuppression and alopecia) associated with most of the chemotherapeutic agents and, in view of its demonstrated objective clinical activity observed in patients harboring resistant solid tumors, the Phase II clinical trials have been initiated and are currently ongoing.

Cisplatin Nephrotoxicity

Cis-dichlorodiammine platinum (II), or cisplatin, has emerged as a principal chemotherapeutic agent in the treatment of otherwise resistant solid tumors and is currently among the most widely used agents in the chemotherapy of cancer. The chief limit to its greater efficacy is its nephrotoxicity, which has made it necessary both to lower its dosage and actively hydrate patients to reduce it. The vulnerability of the kidney to cisplatin is almost certainly related to its primary role in the excretion of cisplatin. Cisplatin enters renal cells by a process that depends on normal oxygen utilization and is specifically inhibited by organic bases. Greater localization of platinum to the S3 segment of the proximal tubules suggests that the vulnerability of this segment may depend on its specific uptake of the drug. The majority of intracellular platinum is bound to macromolecules, including protein and DNA, yet a significant portion of cell platinum is biotransformed to a nonmutagenic and possibly nontoxic compound. Polyuria and hypomagnesemia, which are commonly associated with cisplatin nephrotoxicity, may be due to defects in deep nephron or collecting duct fluid and solute transport. Low single nephron glomerular filtration rates (SNGFR) during early cisplatinum-induced acute renal failure is accompanied by reduced renal blood flow and transglomerular hydrostatic pressure without elevated intratubular hydrostatic pressure, suggesting preglomerular vasoconstriction as an important determinant of renal failure.(ABSTRACT TRUNCATED AT 250 WORDS)

Cancer and immunity

The development of modern tumor immunology based on animal tumor models demonstrated the presence of tumor-specific antigens and the ability of tumor-specific immunity to protect against tumor cell challenge. However, neither of these characteristics are readily attributed to many human cancers. Although in certain animal models induced by virus or carcinogen, antigen-specific T cell (CTL) play an important role against tumor cell killing, the role of specific CTL is not so clear in human cancer.Recently, Brimm et al reported that peripheral blood leukocytes from cancer patients could be activated in culture in preparation of interleukin-2 (IL-2), resulting in the development of effector cells cytotoxic for autologous fresh solid tumor cells. The IL-2-mediated activation of PBL to become cytotoxic to fresh autologous solid tumor cells probably reflects a common and non-specific activation mechanism of the host. As the anomalous killer cells distinct from CTL and NK cell, lectin-activated killer, alloantigen-activated killer and lymphokine-activated killer are included.These cell killings were examined to the PBL of cancer patients.Lymphokine-activated killers represent a unique and fundamental cytotoxic effector system that may play a role in immune surveillance against NK resistant solid tumor cells, and may have a possible role in the adoptive immunotherapy of tumors.The generation of an immune response requires not only the appropriate interaction of cells from the monocytic and lymphoid lineages but also the release of appropriate cytokine by these cell populations. Evidemce is accumulating that many of the functions attributed to lymphocytes and monocytes are actually mediated by the cytokines they release. IL-2 is a lymphokine that is released by T cells after appropriate stimulation. IL-2 production activity in peripheral T cells of cancer patients was examined using IL-2 dependent T CTLL cell lines. The action of IL-2 is of the essential growth factor supporting the in vitro proliferation of T suppressor/cytotoxic cells, lymphokine-activated and NK cells. Furthermore, IL-2 enhances the functional activity of both lymphokine-activated and NK cells.The adopttve immunotherapy using IL-2 will be effective to cancer patients. Tumor necrosis factor (TNF) in one of monokine which has marked anti-tumor activity in vitro and in vivo experiments.Recently human recombinant IL-2 and TNF have been made in my country. The availability of molecular-cloned IL-2 and TNF offers the great advantages to the patients.

High dose chemotherapy with autologous marrow rescue in the treatment of resistant solid tumors.

Toxicity in the form of marrow suppression has hampered the investigation of intensive chemotherapy as it applies to the treatment of solid tumors. The use of autologous marrow rescue to ameliorate protracted aplasia permits the application of high dose chemotherapy to the treatment of solid tumors. We review the theoretical limitations of this technique and present results reported in selected solid tumors. Autologous marrow rescue from intensive chemotherapy is an innovative approach in overcoming the resistence to chemotherapy that is typical of solid tumors. The role of this therapy in the treatment of solid tumors remains to be defined.

Solid tumor models for the assessment of different treatment modalities. VIII. The scheduling of treatment for a chemotherapeutically resistant experimental solid tumor

Single, large doses of adriamycin, cyclophosphamide and 5-fluorouracil (5-FU) have been compared to the same amount of drug given in divided doses daily over a 3 or 5 day period in a solid tumor model which metastasizes to the regional lymph nodes and lungs. No significant increase in life expectancy occurred following adriamycin or cyclophosphamide. However, a significant reduction in life expectancy occurred after 5 fractionated doses of 5-FU but not after the large single dose. The increase in mortality following fractionated doses of 5-FU is attributed to the prolongation of the onset of recovery of bone marrow. Tumor volume reduction following a single dose of each agent was equal to or greater than the fractionated doses. The results of these studies on this chemotherapeutically resistant solid tumor indicate that small daily fractionated doses of adriamycin, cyclophosphamide or 5-FU result in increased morbidity and mortality without therapeutic benefit in tumor control. The time sequence of recovery of the limiting organ of the host (i.e., bone marrow) is similar to the time sequence of recovery of the tumor. Large intermittent single doses of chemotherapeutic agents given following recovery of the host from a previous treatment would be expected to be less toxic to the host and equally effective in control of tumor growth. None of the 3 chemotherapeutic agents was successful in tumor eradication. Previous studies of this series have shown that the utilization of sequential chemotherapy combined with radiotherapy can be successfully used for eradication of another solid tumor which did not metastasize. A similar therapeutic strategy using sequential combined modality therapy should also be effective in the control of the primary H-4-II-E tumor as well as its metastatic dissemination. Information gained from these experimental studies should eventually provide information which should be helpful in the clinical management of chemotherapeutically resistant solid tumors in man.