Complex Proximal Humeral Fracture Fixation with PHILOS Plate using Minimal Invasive Percutaneous Plate Osteosynthesis (MIPPO) Technique: A Series of 30 Patients.

Introduction: Proximal humerus fracture fixation using plate osteosynthesis depends on the quality of the bone, design of the fixation devices and intra-operative soft tissue dissection. This study evaluates the functional outcome of minimally invasive percutaneous plate osteosynthesis using locking compression plate in proximal humerus fracture treatment. Materials and Methods: The study was conducted on 30 patients with complex proximal humerus fractures treated by minimally invasive percutaneous plate osteosynthesis using locking compression plate (PHILOS). There were 21 males and 9 females. The average age of our study group was 58.8 years. All the patients were evaluated at six weeks, three months, four months, six months and 12 months following surgery. Results: All patients had fracture union at an average of 13.2 weeks. The mean DASH score at the follow-up was 8.69 (2.5 to 17.16), the average range of flexion was 143.83 degrees (100 to 170 degrees) and abduction was 121.49 degrees (90 to 160 degrees). We had superficial infection in three patients which resolved with a short course of antibiotics. There was excellent outcome in 26 patients, good and fair in two patients each. Conclusion: Proximal humerus fractures treated with minimally invasive percutaneous plate osteosynthesis using locking compression plate with minimal soft tissue dissection, provides good functional outcome and early return of shoulder function.

Haglund Deformity - Surgical Resection by the Lateral Approach.

The aim of this study was to analyse the outcome of surgical Haglund deformity is a prominence in the postero superolateral aspect of the calcaneum. Haglund deformity is a prominence in the postero superolateral aspect of the calcaneum, causing a painful bursitis, which may be difficult to treat by non-operative measures alone. Various surgical methods are available for effective treatment of refractory Haglund's deformity. This study is to evaluate whether adequate resection of Haglund deformity by a lateral approach provides good to excellent results. During the period from 2009 to 2012, 40 patients with 46 feet had undergone resection of Haglund deformity using lateral approach and the outcome was analysed using AOFAS Ankle-Hind Foot Scale. The mean AOFAS score at the follow up was 86/100, with the majority of patients reporting alleviation of pain at one year follow up. The lateral approach to calcaneal ostectomy can be an effective treatment for those suffering from refractory Haglund deformity. However, the patient must be made aware of theduration of recovery being long.

Myositis ossificans traumatica causing ankylosis of the elbow.

Myositis ossificans traumatica is an unusual complication following a muscle contusion injury. A significantly large myositic mass causing ankylosis of the elbow is even rarer. We report a 13-year-old boy who presented with a 14-month history of a fixed elbow with no movement and a palpable bony mass in the anterior aspect of the elbow. He had sustained significant trauma to the affected limb 1 month prior to onset of symptoms, which was managed by native massage and bandaging for 4 weeks. The clinicoradiological diagnosis was suggestive of myositis ossificans, and the myositic mass was completely excised. Histopathology revealed lamellar bone. The 2-year follow-up showed full function of the affected limb and no signs of recurrence. We report this case of clinical interest due to the unusually large myositic mass.

Adaphostin and other anticancer drugs quench the fluorescence of mitochondrial potential probes.

Fluorescent dyes are widely used to monitor changes in mitochondrial transmembrane potential (DeltaPsim). When MitoTracker Red CMXRos, tetramethylrhodamine methyl ester (TMRM), and 3,3'dihexyloxacarbocyanine iodide (DiOC6(3)) were utilized to examine the effects of the experimental anticancer drug adaphostin on intact cells or isolated mitochondria, decreased fluorescence was observed. In contrast, measurement of tetraphenylphosphonium uptake by the mitochondria using an ion-selective microelectrode failed to show any effect of adaphostin on DeltaPsim. Instead, further experiments demonstrated that adaphostin quenches the fluorescence of the mitochondrial dyes. Structure-activity analysis revealed that the adamantyl and p-aminobenzoic acid moieties of adaphostin are critical for this quenching. Anticancer drugs containing comparable structural motifs, including mitoxantrone, aminoflavone, and amsacrine, also quenched the mitochondrial probes. These results indicate the need for caution when mitochondrial dyes are utilized to examine the effects of xenobiotics on DeltaPsim and suggest that some previously reported direct effects of anticancer drugs on mitochondria might need re-evaluation.

Effects of the bcr/abl kinase inhibitors AG957 and NSC 680410 on chronic myelogenous leukemia cells in vitro.

The tyrphostin AG957 (NSC 654705) inhibits p210bcr/abl, the transforming kinase responsible for most cases of chronic myelogenous leukemia (CML). The present studies were performed to determine the fate of AG957-treated cells and assess the selectivity of AG957 for CML myeloid progenitors. When K562 cells (derived from a patient with blast crisis CML) were treated with AG957, dose- and time-dependent p210bc/abl down-regulation was followed by mitochondrial release of cytochrome c, activation of caspase-9 and caspase-3, and apoptotic morphological changes. These apoptotic changes were inhibited by transfection with cDNA encoding dominant negative caspase-9 but not dominant-negative FADD or blocking anti-Fas antibodies. In additional experiments, a 24-h AG957 exposure caused dose-dependent inhibition of K562 colony formation in soft agar. To extend these studies to clinical samples of CML, peripheral blood mononuclear cells from 10 chronic phase CML patients and normal controls were assayed for the growth of hematopoietic colonies in vitro in the presence of increasing concentrations of AG957. These assays demonstrated selectivity of AG957 for CML progenitors, with median IC50s (CML versus normal) of 7.3 versus >20 microM AG957 in granulocyte colony-forming cells (P < 0.001), 5.3 versus >20 microM in granulocyte/macrophage colony-forming cells (P < 0.05), and 15.5 versus > 20 microM in erythroid colony-forming cells (P > 0.05). The adamantyl ester of AG957 (NSC 680410) down-regulated p210bcr/abl in K562 cells and inhibited granulocyte colony formation in CML specimens at lower concentrations without enhanced toxicity in normal progenitors. These observations not only demonstrate that AG957-induced p210bcr/abl down-regulation is followed by activation of the cytochrome c/Apaf-1/caspase-9 pathway but also indicate that this class of kinase inhibitor exhibits selectivity worthy of further evaluation.

Antitumor agents. 196. Substituted 2-thienyl-1,8-naphthyridin-4-ones: their synthesis, cytotoxicity, and inhibition of tubulin polymerization.

As part of our continuing search for potential anticancer drug candidates in the 2-aryl-1,8-naphthyridin-4-one series, we have synthesized a series of substituted 2-thienyl-1, 8-naphthyridin-4-ones. Most compounds showed significant cytotoxic effects (log GI(50) < -4.0; log molar drug concentration required to cause 50% growth inhibition) against a variety of human tumor cell lines in the National Cancer Institute's in vitro screen, including cells derived from solid tumors such as non-small-cell lung, colon, central nervous system, melanoma, ovarian, prostate, and breast cancers. The most active compounds (31-33,40) demonstrated strong cytotoxic effects with ED(50) values in the micromolar or submicromolar range in most of the tumor cell lines. The most cytotoxic compounds inhibited tubulin polymerization at concentrations substoichiometric to the tubulin concentration. The most potent inhibitors of polymerization (40,42,43) had effects comparable to those of the potent antimitotic natural products podophyllotoxin and combretastatin A-4 and to that of NSC 664171, a particularly potent, structurally related analogue. Only compound 40 was a potent inhibitor of the binding of radiolabeled colchicine to tubulin, and it was both the most cytotoxic agent and the most effective inhibitor of polymerization among the newly synthesized compounds.

Identification of novel antitumor agents from mixture-based synthetic combinatorial libraries using cell-based assays.

A new strategy is presented here which integrates combinatorial library technology with the antitumor in vitro screening system at the National Cancer Institute in the search for novel antitumor agents. Mixture-based synthetic combinatorial libraries (SCLs) representing hundreds of thousands to millions of individual compounds were screened against the cell-based assay, which evaluates compounds for their ability to inhibit the growth of 60 different human tumor cell lines. Five different SCLs, composed of peptides, peptidomimetics, polyamines or small molecules were first tested against three cell lines to identify the most active SCLs. Two SCLs, namely the N-perbenzylated pentamine and the N-acylated permethylated triamine, were deconvoluted to yield individual compounds having significant activities against the 60 tumor cell lines. Active compounds were tested in mice to determine the maximum tolerated dose, followed by in vivo testing in a hollow fiber assay. Using this strategy, three different compounds identified directly from SCLs are currently being evaluated in human tumor xenografts. This study demonstrates for the first time the use of in vitro cell-based assays to identify antitumor lead compounds from mixture-based combinatorial libraries.

Synthesis, antiinflammatory, and cytotoxic activities of 2-alkyl and 2-benzyl-2-dimethylaminomethyl-5-(E)-arylidene cyclopentanone hydrochlorides.

PURPOSE: A series of 2-substituted-2-dimethylaminomethyl-5-(E)-arylidene cyclopentanones, 4 were synthesized. The main objective of this investigation was to explore the structural parameters necessary for antiinflammatory activity in this series of compounds, while keeping cytotoxic action to a minimum. METHODS: The target compounds were synthesized in two steps commencing with 2-alkyl-cyclopentanones. Antiinflammatory, analgesic and cytotoxic activities were determined in rats. Cytotoxic results were examined in human cell lines. RESULTS: Eight of the eighteen synthetic substances possessed significant antiinflammatory activity and twelve showed appreciable analgesic action. Cytotoxicity was minimal or non-existent for most of the compounds. The stability of one of the compounds, 4b in both aqueous and non-aqueous media, and an amine exchange reaction with aniline were used to explain the observed antiinflammatory and cytotoxic activities. CONCLUSIONS: Unlike monosubstituted aminomethyl groups (Mannich bases) at the 2-position of 5-arylidene-2-cyclopentanones, a second substituent at the 2-position increases stability of the Mannich base and significantly decreases cytotoxic activity. Antiinflammatory and analgesic action is retained in many of the compounds, thus strongly indicating that these desired pharmacological results can be obtained without untoward damage to cells.

Synthesis and cytotoxic activities of the amine-exchange products of 2-dimethylaminomethyl-5-(E)-substituted arylidene cyclopentanones with anilines: 2-arylaminomethyl-5-(E)-arylidene cyclopentanones.

A series of 2-arylaminomethyl, and 2-(4-morpholinylmethyl)-5-(E)-arylidene cyclopentanones have been synthesized via an amine-exchange reaction. Most of the compounds showed significant cytotoxic activities, in vitro, on various human cancer cell lines. Generally, compounds with a para-chloroanilino moiety were more active than those of other aniline derivatives. No apparent changes were observed by altering the substituents on the arylidene portion. For the majority of active compounds, leukemia is one of the most sensitive subpanels at both GI50 and TGI levels but the least sensitive one at the LC50 level. Colon cancer is one of the most sensitive subpanels in all three levels. COMPARE results indicated that the characteristics, and possibly the mechanism of the cytotoxic properties of the 2-arylaminomethyl derivatives might be different from that of the 2-dialkylaminomethyl derivatives previously reported.

Biological and biochemical anti-human immunodeficiency virus activity of UC 38, a new non-nucleoside reverse transcriptase inhibitor.

UC 38, a simple analog of oxathiin carboxanilide, UC 84, lacking the oxathiin ring, was found to be a potent inhibitor of human immunodeficiency virus (HIV)-1-induced cell killing and HIV replication in a variety of human cell lines, as well as in human peripheral blood lymphocytes and macrophages. UC 38 was active against a wide range of biologically diverse laboratory and clinical strains of HIV-1. However, UC 38 was inactive against HIV-2 and both nevirapine- and pyridinone-resistant strains of HIV-1. UC 38 selectively inhibited HIV-1 reverse transcriptase (RT), but not HIV-2 RT. Combination of UC 38 with 3'-azido-3'-deoxythymidine synergistically inhibited HIV-induced cell killing. An HIV-1 isolate resistant to UC 38 was selected in cell culture, and the mutations in the RT nucleotide sequences were determined. Comparison with the wild-type RT sequence revealed an amino acid change at position 181 (Tyr to Cys). The UC 38-resistant virus was found to be cross-resistant to a variety of structurally diverse non-nucleoside RT inhibitors. UC 38 was susceptible to rapid degradation in vitro and in vivo; yet, nontoxic in vivo concentrations of UC 38 many-fold in excess of the in vitro effective concentrations could be achieved and maintained after s.c. or p.o. administration in hamsters. These results establish UC 38 as a new chemotype within the general class of HIV-1-specific RT inhibitors. The favorable physical characteristics, lack of toxicity, potency and bioavailability of UC 38 may make it a candidate for combination chemotherapy of acquired immune deficiency syndrome.

Synthesis, antitumor activity, and chemical properties of silaplatin and related platinum (II) and platinum (IV) complexes derived from beta-silyl amines.

Platinum (II) and platinum (IV) coordination complexes derived from beta-silyl-substituted amines were prepared. The solubility of selected complexes in water and physiological saline was measured, and the effect of the beta-silicon on the reactivity of the complex in aqueous solution was determined by HPLC. The stabilities of selected silyl complexes were compared to the carbon analogues. The cyclic complexes 2a ("silaplatin") and its Pt(IV) analogue, 2b, were very active against L1210 leukemia in vivo. Both the platinum (II) complex 2a and the platinum (IV) complex 2b produced a significant number of cures over the dose range 10-40 mg/kg. The platinum (II) complex 2a, silaplatin, was very active in vivo against an L1210 leukemia subline that was resistant to cisplatin; 2a was also active, when given ip, against ic implanted L1210. The cyclobutanedicarboxylic acid complex 3c was synthesized; this complex was active against both cisplatin sensitive and resistant L1210 leukemia but was less potent than the analogous dichloro compound 2a. The acyclic platinum (II) and platinum (IV) complexes 1a,b were synthesized and unexpectedly found to be inactive in vivo against L1210 leukemia. More lipophilic silaplatin analogues were prepared--Pt(II) complex 2c and Pt(IV) complex 2d have one additional methylene carbon compared to 2a,b, whereas Pt(II) complex 2e and Pt(IV) complex 2f have two additional methylene carbons. Cyclization of the alkyl groups attached to the silicon gave the spiro bicyclic Pt(II) complexes 10a and 11a and the Pt(IV) complexes 10b and 11b.

Antineoplastic agents 322. synthesis of combretastatin A-4 prodrugs.

Combretastatin A-4 (1a), the principal cancer cell growth-inhibitory constituent of the Zulu medicinal plant Combretum caffrum, has been undergoing preclinical development. However, the very limited water solubility of this phenol has complicated drug formation. Hence, derivatives of the combretastatin A-4 (1a) 3'-phenol group were prepared for evaluation as possible water-soluble prodrugs. As observed for combretastatin A-4, the sodium salt (1b), potassium salt (1c) and hemisuccinic acid ester (1e) derivatives of phenol 1a were essentially insoluble in water. Indeed, these substances regenerated combretastatin A-4 upon reaction with water. A series of other simple derivatives (1d, 1f-j) proved unsatisfactory in terms of water solubility or stability, or both. The most soluble derivatives evaluated included the ammonium (1l), potassium (1m) and sodium (1n) phosphate salts, where the latter two proved most stable and suitable. Both the potassium (1m) and sodium (1n) phosphate derivatives of combretastatin A-4 were also found to exhibit the requisite biological properties necessary for a useful prodrug. Sodium salt 1n was selected for drug formulation and further pre-clinical development.

Efficacy of the quinocarmycins KW2152 and DX-52-1 against human melanoma lines growing in culture kand in mice.

Quinocarmycin monicitrate (KW2152) and its analogue, DX-52-1, demonstrated specificity for melanomas in the National Cancer Institute in vitro human tumor cell line drug screen. In contrast to most cell lines, a 50% reduction in tumor cell burden (as measured protein) at the end of a 48-h drug incubation was produced in five of eight melanoma lines by KW2152 concentrations (LC50s) ranging from 0.49 to 10.93 microM and by DX-52-1 concentrations ranging from 0.71 to 7.33 microM. Using the COMPARE algorithm, the patterns of differential cytotoxicity for both agents at the LC50 level of effect most closely resembled those for actinomycin D, mithramycin, and Adriamycin. In in vivo studies, both KW2152 (40 mg/kg/day) and DX-52-1 (90 mg/kg/day) caused partial and complete regressions of staged s.c.-implanted LOX IMVI melanoma xenografts following i.p. administration on days 5, 9, and 13 and produced tumor growth delays of 231 and 181%, respectively (P < 0.001). Activity was augmented by more prolonged therapy. Statistically significant growth inhibition of SK-MEL-2, UACC-62, UACC-257, and M14, but not SK-MEL-5 and MALME-3M, melanoma xenografts also was observed following every fourth or seventh day i.p. treatments. Based on these findings, DX-52-1 has been selected by the National Cancer Institute for development to clinical trial especially against melanomas. This agent represents one of the first to be selected for preclinical development based on disease-panel specificity discovered in the National Cancer Institute cancer drug screen.

Synthesis and anti-cancer activity of 2-alkylaminomethyl-5-(E)-alkylidene cyclopentanone hydrochlorides.

A series of 2-alkylaminomethyl-5-(E)-alkylidene cyclopentanone hydrochlorides (2), have been synthesized and evaluated as anti-cancer agents. These compounds were designed as masked alpha-methylenecyclopentanones, which appear in many cytotoxic or anti-cancer natural products. Most of the synthesized compounds were found to be active towards various human cancer cell lines and many showed significant subpanel selectivity. For compounds containing the same alkylidene moiety (from C3 to C9), the dimethylaminomethyl analogs were more active than structures possessing morpholino-, pyrrolidino-, or piperidino-methyl groups. Alteration of the alkylidene moiety had little effect on anti-cancer potency. The mass spectrum of a glutathione adduct of 2h indicated that the mechanism of action for these anti-cancer agents may be related to the attack at the aminomethyl carbon atom by biological nucleophilic thiols.

Anticancer specificity of some ellipticinium salts against human brain tumors in vitro.

Novel structure-activity relationships (SAR) distinct from known SAR for ellipticines have been revealed for certain ellipticinium salts. In particular, ellipticiniums such as the prototypical 9-methoxy-2-methylellipticinium (I- or OAc-) were found to be preferentially cytotoxic to the brain tumor cell line subpanel of the NCI 60 cell-line screening panel. Similar specificity also was apparent with 9-unsubstituted ellipticiniums, or others bearing 9-methyl or 9-chloro substituents. In contrast, 9-hydroxy-substituted ellipticiniums, as well as all nonquaternized ellipticines tested, were devoid of brain tumor specificity. Therefore, it did not appear that this unusual preference was correlated with the relative availability of redox cycling mechanisms, since redox cycling presumably is blocked in 9-methyl- and 9-chloroellipticiniums. Indeed, related investigations have indicated that the brain tumor specificity is mediated by preferential uptake and intracellular accumulation of the specific ellipticiniums. The present study further supports that the NCI in vitro "disease-oriented" primary screen can facilitate the discovery of novel, selectively cytotoxic leads for in vivo and mechanistic investigations.

Diarylsulfones, a new chemical class of nonnucleoside antiviral inhibitors of human immunodeficiency virus type 1 reverse transcriptase.

A series of variously substituted diarylsulfones and related derivatives were found to prevent human immunodeficiency virus type 1 (HIV-1) replication and HIV-1-induced cell killing in vitro. One of the more potent derivatives, 2-nitrophenyl phenyl sulfone (NPPS), completely protected human CEM-SS lymphoblastoid cells from the cytopathic effects of HIV-1 in cell culture at 1 to 5 microM concentrations. HIV-1 replication, as assessed by the production of infectious virions, viral p24 antigen, and virion reverse transcriptase (RT), was inhibited by NPPS at similar concentrations. There was no evidence of direct cytotoxicity of the drug at concentrations below 100 microM. A variety of other CD4+ T-cell lines as well as cultures of peripheral blood leukocytes and monocytes were protected from HIV-1-induced cytopathicity and/or viral replication. NPPS also inhibited several distinctly different strains of HIV-1 but was ineffective against three strains of HIV-2. Biochemical studies revealed that NPPS inhibited HIV-1 RT but not HIV-2 RT. NPPS had no direct effect on HIV-1 virions, nor did it block the initial binding of HIV-1 to target cells. Time-limited treatments of cells with NPPS found that NPPS had to be present continuously in culture to provide maximum antiviral protection. In addition, HIV-1 replication in cells in which infection was already fully established or in chronically infected cells was also unaffected by NPPS. We conclude that NPPS acts in a reversible manner as a nonnucleoside HIV-1-specific RT inhibitor. Although markedly different in structure from a larger, structurally diverse group of known HIV-1-specific nonnucleoside RT inhibitors, NPPS shares several of the biological properties that characterize this emerging new pharmacologic class.

Oxathiin carboxanilide, a potent inhibitor of human immunodeficiency virus reproduction.

Oxathiin carboxanilide (OC), NSC 615985, a compound originally synthesized as a potential fungicide, was demonstrated to be highly active in preventing human immunodeficiency virus (HIV)-induced cell killing and in inhibiting HIV reproduction. Virus-infected CD4+ lymphocytes were completely protected by 0.5 microM OC, whereas no toxicity was observed at concentrations below 50 microM OC. Production of infectious virus, viral p24 antigen, and virion reverse transcriptase were reduced by OC at concentrations that prevented viral cell killing. A variety of CD4+ T-cell lines were protected by OC from HIV cytopathicity, and OC inhibited two distinct strains of HIV-1. However, HIV-2 infections were unaffected by OC. OC had no direct effect on virions of HIV or on the enzymatic activities of HIV reverse transcriptase or HIV protease. Time-limited treatments of cells with OC before, during, or after exposure of cells to virus failed to protect cells from the eventual cytopathic effects of HIV, and OC failed to inhibit the production of virus from cells in which infection was established or from chronically infected cells. We conclude that the highly active OC has a reversible effect on some early stage of HIV-1 reproduction and cytopathicity. Pilot in vivo experiments showed that circulating concentrations of OC exceeding 1 microM could be achieved and sustained in hamsters for at least a week with no remarkable toxicological sequelae. OC represents a new class of anti-HIV agents that are promising candidates for drug development.

Synthesis of congeners and prodrugs. 3. Water-soluble prodrugs of taxol with potent antitumor activity.

Taxol has shown good in vivo antitumor activity in a number of test systems. The formulation of taxol for antitumor testing has been difficult. Esterification at either C-2' or C-7 resulted in loss of in vitro tubulin assembly activity but not cytotoxicity. These observations suggested that esters at C-2' and/or C-7, which would tend to promote water solubility, might serve as useful prodrugs of taxol. The reaction of taxol with either succinic anhydride or glutaric anhydride in pyridine solution at room temperature gave the crystalline mono 2'-adducts 1b and 1f, respectively. Salts of these acids (1b, 1f, 1i) were formed by the addition of 1 equiv of the corresponding base, followed by evaporation and/or freeze-drying of the solvent(s). The salts had improved antitumor activity as compared to the free acids. The triethanolamine and N-methylglucamine salts showed greatly improved aqueous solubility and were more active than the sodium salts. The glutarate series was preferred because of the higher activity and the higher yields obtained. 2'-Glutaryltaxol (1f) was coupled with 3-(dimethylamino)-1-propylamine, using CDI, to form in excellent yield the amino amide 1o. The hydrochloride salt (1p) showed good solubility and was extremely potent and active. At 10 mg/kg, in the B16 screen, 1p gave a T/C of 352 with 5 out of 10 cures. In the MX-1 breast xenograft assay, this prodrug gave values of -100 at doses of 40 and 20 mg/kg, with all live animals being tumor free.

Preclinical antitumor activity of an alpha-picoline derivative, penclomedine (NSC 338720), on human and murine tumors.

Penclomedine, a synthetic alpha-picoline derivative, was identified as a potential antitumor agent in the P388 leukemia prescreen of the National Cancer Institute. Upon further evaluation in the National Cancer Institute in vivo tumor panel, the compound demonstrated good activity against two breast tumors. A single i.p. dose or five daily doses caused partial regressions of advanced-stage s.c. implanted mouse CD8F1 mammary adenocarcinomas. Also, penclomedine administered i.p. on Days 1,5, and 9 caused regression of the human MX-1 mammary carcinoma implanted under the renal capsule of athymic mice. In contrast, penclomedine demonstrated only marginal to moderate activity against the i.p. implanted L1210 leukemia and M5076 sarcoma and was inactive in three additional non-breast tumor models (i.p. B16 melanoma, i.v. Lewis lung carcinoma, and s.c. colon adenocarcinoma 38). Penclomedine administered p.o. and i.p. was equally effective against the subrenal capsule MX-1. Doses given p.o. every fourth day caused complete regression of 39 of 40 advanced-stage s.c. implanted MX-1 tumors but were much less effective against human H82 small cell lung carcinomas (13 of 80 complete regressions). Penclomedine p.o. also inhibited growth of the human MCF-7 and mouse 16/C breast adenocarcinomas. Further studies to support the development of penclomedine to clinical trial are in progress.