Vincristine alters myoelectric activity and transit of the small intestine in rats

We investigated the motility of the small intestine in unanesthetized rats receiving vincristine (0.075, 0.50, 0.75 mg/kg i.v.). Motility was determined by two methods: myoelectric activity was monitored with indwelling bipolar electrodes, and intestinal transit was measured by the movement of radiochromium (Na51CrO4). Only the animals injected with the two higher doses had two distinct patterns of altered intestinal myoelectric activity within 2 h of drug administration. The first alteration occurred 44 +/- 6 min after vincristine administration and consisted of a marked increase in action potential activity with disruption of the migrating myoelectric complex. The second alteration consisted of a reappearance of the activity front of the migrating myoelectric complex with a significantly shorter periodicity. A marked reduction in spike activity occurred 3 days after vincristine injection in 3 of 10 animals receiving vincristine. A biphasic response was noted in intestinal transit. Disrupted activity front formation was associated with a significant delay in small bowel transit. In contrast, frequent activity front formation in rats was associated with significantly hastened transit. In summary, vincristine administration induces alterations of myoelectric activity of the small intestine in fasted rats and is associated with changes in intestinal transit.     

Excess prevalence of Pneumocystis carinii pneumonia in patients treated for lymphoma with combination chemotherapy

A significantly greater prevalence of interstitial pulmonary infiltrates and Pneumocystis carinii pneumonitis occurred on one arm of a randomized study comparing ProMACE-CytaBOM (prednisone, methotrexate with leucovorin, doxorubicin, cyclophosphamide, etoposide; cytarabine, bleomycin, vincristine, methotrexate with leucovorin) to ProMACE-MOPP (ProMACE, mechlorethamine, vincristine, prednisone, procarbazine) chemotherapy in patients with lymphoma. Of the 37 patients receiving ProMACE-CytaBOM, 13 (35.1%) developed an interstitial pulmonary infiltrate compared with 3 of 32 (9.4%) patients receiving ProMACE-MOPP (p2 = 0.02). Of the 13 patients receiving ProMACE-CytaBOM who had infiltrates, open lung biopsy in 7 showed P. carinii; 5 others had clinically suspected P. carinii pneumonia, and 1 had blastomycosis. No patient receiving ProMACE-MOPP had documented or suspected P. carinii pneumonia. Of patients with infiltrates, 3 of 13 on ProMACE-CytaBOM but 0 of 3 on ProMACE-MOPP died. Two other patients on ProMACE-CytaBOM who had P. carinii pneumonia died. Groups did not differ in predisposing risk factors or patient history. The exact cause for the increased prevalence of P. carinii infection in patients receiving ProMACE-CytaBOM was not ascertained. These data emphasize that new drug regimens may lead to unanticipated complications.     

2 new cases of myocardial infarction after injection of vincristine

The authors report two cases of myocardial infarction following the injection of vincristine. The vincristine is held responsible for several reasons: absence of past history or risk factors of coronary artery disease, no past history of mediastinal radiotherapy, the development of coronary manifestations several hours after the injection of vincristine. Both cases followed a fatal course. The pathophysiology of this iatrogenic complications is unclear. Any patient receiving such treatment should be carefully monitored clinically and electrocardiographically.     

The Effect of Vincristine on the Platelet Count in Rats

The effect of vincristine on the platelet count of rats is described. It was found that, depending upon dosage, the drug can cause either a thrombocytosis or marrow hypoplasia with thrombocytopenia in normal rats. Thrombocytosis was found even after prolonged treatment with vincristine when this was given at appropriate dosage.
The thrombocytosis promoting effect of the drug was not enhanced by an increase in the splenic platelet pool or decreased by splenectomy. However, it was abolished when prior treatment was given to suppress marrow thrombopoiesis.     

Effects of a microtubule stabilizing agent on the response of platelets to vincristine

The discoid shape of blood platelets is supported by a circumferential bundle of microtubules. Removal of the microtubules by an antimitotic drug, vincristine, is associated with loss of lentiform appearance, formation of tubulin paracrystals, a depressed response to aggregating agents, and impaired secretory activity. Recent studies have suggested that the action of vincristine on platelet secretion and aggregation is directly related to its action on microtubules, while other work had indicated that the antimitotic drug prevents the release reaction by inhibiting prostaglandin synthesis. The present study has examined the influence of taxol, a microtubule stabilizing agent, on the response of platelets to vincristine. Taxol completely prevented vincristine- induced shape change, microtubule disassembly, and tubulin paracrystal formation, even at concentrations one-tenth that of the antimitotic drug. Pretreatment with vincristine to dissociate microtubules and convert tubulin to crystals before exposure to taxol did not affect altered shape or tubulin paracrystals, but did cause assembly of free pools of tubulin into tubular polymers. Studies of physiology confirmed that vincristine, in amounts that remove microtubules, depresses platelet aggregation and secretion, effects that could be overcome by increasing agonist concentration. Although completely preventing microtubule dissociation, taxol had no corrective influence on vincristine-induced inhibition of platelet function. Biochemical studies revealed that vincristine concentrations that disassembled microtubules and blocked secretion did not inhibit conversion of 14C- arachidonic acid to thromboxane B2. The findings suggest that vincristine inhibits platelet function through some mechanism other than disassembling microtubules, but the other mechanism does not involve inhibition of prostaglandin synthesis.     

P-glycoprotein expression in human plasma cell myeloma: correlation with prior chemotherapy

Multidrug-resistant (MDR) myeloma patients failing chemotherapy may express P-glycoprotein (PGP), which serves as an efflux pump protecting the neoplastic cells. Unknown is whether PGP expression might relate to prior cytotoxic drug exposure. To address this question, we studied 106 consecutive bone marrow samples from 104 myeloma patients with samples studied either before or after therapy and at the time of relapse. We performed an established immunocytochemical assay of PGP using an MDR-1- specific monoclonal antibody and correlated PGP status with prior chemotherapy dosage. Myeloma patients with no prior therapy had a low incidence of PGP expression (6%, 3/47), whereas those receiving chemotherapy had a significantly higher incidence (43%, 21/49) (P < .0001). A substantially higher incidence of PGP expression (50%, 83%, respectively) occurred when the total vincristine dose exceeded 20 mg and when doxorubicin exceeded 340 mg. In the 11 patients who received both high vincristine and doxorubicin dosages (> 20 mg, > 340 mg total dose) there was 100% incidence of PGP expression in the tumor cells. These data provided the basis for a predictive mathematical model from which dose-related PGP expression normograms were generated. Time with myeloma for PGP-negative patients (mean 33 months) had overlapping confidence limits with PGP-positive patients (mean 42 months), suggesting that disease duration was not a significant variable. PGP expression did not correlate with other clinical factors or immunophenotypic factors. Our findings indicate a strong correlation between PGP expression in myeloma and past chemotherapy in myeloma, in particular, related to prior exposure to the natural product agents vincristine and doxorubicin. Additionally, the proportion of PGP- positive plasma cells was significantly higher in the doxorubicin- treated patients than the nondoxorubicin-treated patients (87.7% v 65.17%; P = .013). Combined high vincristine and doxorubicin total dosage appear highly predictive of PGP expression.     

Combination chemotherapy in advanced breast cancer.: a randomized trial comparing a three-vs a five-drug program.

A prospective randomized trial was undertaken to compare the efficacy of a three-drug regimen using cyclophosphamide, methotrexate, and fluorouracil to a five-drug regimen using vincristine sulfate and prednisone in addition to cyclophosphamide, methotrexate, and fluorouracil in advanced breast carcinoma. Seventy-two patients who had received no prior chemotherapy were randomized. Thirty-eight patients received three drugs, and 34 received five-drug therapy. The objective response rates, 34% and 50% respectively, did not differ signficantly (P = .13). As expected, myelosuppression occurred in most patients, and neurotoxicity was much more common in patients receiving vincristine. Three of 12 patients treated with the five-drug regimen after progession of disease while receiving the three-drug regiment showed an objective response to the five-drug regimen.     

Reduction of transglutaminase 2 expression is associated with an induction of drug sensitivity in the PC-14 human lung cancer cell line

Recently a role for transglutaminase 2 (TGase 2) in the drug resistance of cancer cells has been suggested, although the mechanism is unclear. In the present study, we observed that doxorubicin-resistant PC-14/ADR cells showed a ten-fold higher level of TGase 2 expression than drug-sensitive PC-14 cells. PC-14/ADR cells exhibited the classical multidrug resistance (MDR) phenotype, which was cross-resistant to vincristine, but not to cisplatin. The stepwise induction of resistance to doxorubicin and vincristine in PC-14 cells was accompanied by a gradual increase of TGase 2 expression, but this expression was not increased with induction of cisplatin resistance. To confirm the role of TGase 2 protein in the acquisition of drug resistance in PC-14 cells, the TGase 2 expression in PC-14/ADR cells was reduced by stable transfection with the antisense or ribozyme construct. In the clones showing reduced expression of TGase 2, lactate dehydrogenase released from drug-treated cells was increased in the presence of either MDR-related drugs (doxorubicin and vincristine) or a non-MDR-related drug (cisplatin). These data suggest that TGase 2 can play a role in the acquisition of drug resistance in PC-14 cells through a general cellular defense system other than the MDR-related system. Received: 22 September 1998 / Accepted: 16 November 1998     

Amelioration of vincristine neurotoxicity by glutamic acid

Neurotoxicity is the principal limiting side effect of the widely used antitumor agent, vincristine. Following evaluation of glutamic acid as a potential modifier of vincristine toxicity in preclinical studies in mice and a preliminary clinical trial, a prospective, double-blind, placebo-controlled, randomized trial was conducted by the Piedmont Oncology Association. Of 87 patients entered into the study, 84 were evaluable, including 42 patients who were randomly assigned to receive vincristine 1.0 mg/m2 weekly for six doses and 42 patients who were assigned to receive glutamic acid 500 mg orally three times daily plus vincristine. The following neurotoxic signs and symptoms were evaluated before each dose of vincristine: reflex changes, paresthesias, constipation, strength, and mental changes. Loss of the Achilles tendon reflex, an objective parameter, was noted in 19 percent of patients receiving glutamic acid and 42 percent of control subjects (p = 0.03). Development of moderate to severe paresthesias, a subjective parameter, occurred in 19 percent of the glutamic acid group and 36 percent of the placebo group (p = 0.09). Overall moderate neurotoxicity (6 units or more), determined by adding the grade of each neurotoxic parameter for the weekly clinic visit in which maximum neurotoxicity occurred, was observed in 21 percent of patients receiving glutamic acid and 43 percent of those in the control group (p = 0.04). Hematologic and gastrointestinal side effects occurred with similar frequency in the two groups. The administration of glutamic acid has decreased vincristine-induced neurotoxicity without any attendant side effects.     

Perturbation of in vitro drug resistance in human lymphatic neoplasms by combinations of putative inhibitors of protein kinase C

Fresh specimens of human lymphatic neoplasms were tested with the differential staining cytotoxicity assay. Cells from relapsed patients with acute lymphoblastic leukemia (ALL) were significantly more resistant to vincristine, dexamethasone, and doxorubicin in the assay than were cells from previously untreated patients. The putative C kinase inhibitors verapamil (V), imipramine (I), lidocaine (L), tamoxifen (T), chlorpromazine (C), and haloperidol (H) were then tested singly, in combination with each other (VILTCH, ITCH, and VL), and in combination with vincristine. At concentrations judged to be clinically achievable, VILTCH itself was occasionally toxic to ALL and chronic lymphocytic leukemia. The VILTCH combination clearly potentiated the cytotoxic activity of vincristine in five of eight ALL specimens from relapsed patients and potentiated vincristine in 18 of 30 chronic lymphocytic leukemia specimens. It also potentiated vincristine in two of six specimens of multiple myeloma and five of six specimens of non-Hodgkin's lymphoma. The VILTCH combination had no significant effects in fresh cultures of normal human lymphocytes. The most active drugs in the VILTCH combination appeared to be verapamil and lidocaine. We conclude that the differential staining cytotoxicity assay is a useful tool to study the circumvention of clinically acquired drug resistance. While the mechanism of the observed enhancement of the cytotoxic effects of vincristine is not known, it is possible that combinations of putative C kinase inhibitors may reduce drug resistance in human lymphatic neoplasms.     

Resistance to vincristine in DLBCL by disruption of p53-induced cell cycle arrest and apoptosis mediated by KIF18B and USP28

The frontline therapy R-CHOP for patients with diffuse large B-cell lymphoma (DLBCL) has remained unchanged for two decades despite numerous Phase III clinical trials investigating new alternatives. Multiple large studies have uncovered genetic subtypes of DLBCL enabling a targeted approach. To further pave the way for precision oncology, we perform genome-wide CRISPR screening to uncover the cellular response to one of the components of R-CHOP, vincristine, in the DLBCL cell line SU-DHL-5. We discover important pathways and subnetworks using gene-set enrichment analysis and protein–protein interaction networks and identify genes related to mitotic spindle organization that are essential during vincristine treatment. The inhibition of KIF18A, a mediator of chromosome alignment, using the small molecule inhibitor BTB-1 causes complete cell death in a synergistic manner when administered together with vincristine. We also identify the genes KIF18B and USP28 of which CRISPR/Cas9-directed knockout induces vincristine resistance across two DLBCL cell lines. Mechanistic studies show that lack of KIF18B or USP28 counteracts a vincristine-induced p53 response suggesting that resistance to vincristine has origin in the mitotic surveillance pathway (USP28-53BP1-p53). Collectively, our CRISPR screening data uncover potential drug targets and mechanisms behind vincristine resistance, which may support the development of future drug regimens.     

The prognosis of HIV-infected patients with diffuse large B-cell lymphoma treated with chemotherapy and highly active antiretroviral therapy is similar to that of HIV-negative patients receiving chemotherapy

In the era of highly active antiretroviral treatment (HAART), the prognosis of AIDS-related lymphomas might be similar to that of aggressive B-cell lymphomas in human immunodeficiency (HIV)-negative patients. In this study we found that HIV-infected patients with diffuse large B-cell lymphoma treated with cyclophosphamide, hydroxydoxorubicin, vincristine and prednisone (CHOP) and HAART showed a similar response rate to chemotherapy, disease-free survival and overall survival as those of HIV-negative patients receiving CHOP.     

Chemotherapy for small cell bronchogenic carcinoma: CCNU and doxorubicin compared to CCNU, doxorubicin, vincristine, and procarbazine

Forty consecutive patients with small cell bronchogenic carcinoma were treated. The first 18 patients were treated with CCNU and doxorubicin (Adriamycin) (CA). The next 22 patients were treated with CCNU, doxorubicin, procarbazine, and vincristine (CAPO). Patient characteristics were similar. The partial plus complete response rate was 55% (ten of 18 patients) in the CA group compared to 41% (nine of 22 patients) in the CAPO group. The median survival from treatment was 28 weeks in the CA group compared to 33 weeks in the CAPO group. There were no drug-related deaths among the patients receiving CA compared to two definite and three probably drug-related deaths among the patients receiving CAPO. The addition of procarbazine and vincristine to CA for the treatment of small cell bronchogenic carcinoma resulted in increased toxicity and no survival benefit.     

Effect of Vincristine on Platelet Production in Mice

Platelet production was investigated using [⁷⁵Se]selenomethionine bio-assay in C57BL mice after a single injection of vincristine within the dose range 0.2–3.2 mg/kg. The changes in the circulating platelet count were also followed. There was an immediate, not strictly dose-dependent, fall in the number of platelets, a quick recovery with an overshoot after small doses, delayed recovery with a moderate overshoot after intermediate doses and a slow recovery returning to normal levels after large doses. The drug caused an overproduction of platelets with every dose used, but this was not necessarily reflected in the peripheral platelet count. It seems unlikely, at least after the smaller doses, that the early fall in platelets plays a role in the increased platelet production. Platelet precursors are resistant to a single dose of vincristine and the drug may have a primary stimulatory effect on the megakaryocytopoietic system.     

Potentiation of vincristine cytotoxicity by hormones: Corticosteroids,androgens, estrogens and progestins

Using an in vitro system to evaluate the simultaneous use of two drugs, we previously have confirmed the synergism of vincristine and prednisolone cytotoxicity against lymphoid cells. Experiments were now carried out to determine whether other steroid hormones can be substituted for prednisolone. Partial or complete potentiation of vincristine cytotoxicity comparable to that achieved by the addition of prednisolone was observed when the latter drug was replaced by a variety of mineralocorticoids (aldosterone, desoxycorticosterone and fludrocortisone), glucocorticoids (hydrocortisone, dexamethasone), androgens (testosterone, methyltestosterone, androsterone, dehydroepiandrosterone, etiocholanolone), estrogens (estrone, 17-βestradiol) and progestins (progesterone, pregnanediol). No potentiation of cytotoxicity was observed when nonsteroidal hormones (thyroxin, ACTH) were added to vincristine. It is concluded that a wide variety of compounds with the basic perhydrocyclopentano-phenanthrene nucleus of the steroid molecule are capable of enhancing the cytotoxicity achieved with vincristine.     

Two dimensional view of combination chemotherapy in vitro

A newly developed micromethod to evaluate the cytotoxic effects of drugs on rapidly growing lymphoid cell lines is described, which permits evaluation of more than one variable. This technique allows a checkerboard titration of two drugs to determine the optimum concentration of each needed for the augmentation of the other's cell-killing activity. Such studies have shown that the minimum concentration of vincristine capable of killing a human lymphoid cell population is 5.6 ng/ml. The addition of prednisolone at a concentration of 460 ng/ml reduces the minimum lethal concentration of vincristine to 1.6 ng/ml. When prednisolone is added to vincristine at concentrations of 2.8 mu/ml (a level readily achieved in the serum in vivo) concentrations of vincristine as low as 200 pg/ml are clearly cytotoxic. Similar potentiation of cytotoxicity following the addition of prednisolone has been demonstrated for cytosine arabinoside, but not for daunorubicin and only slightly for methotrexate. The micromethod for the study of optimal doses to be used in drug combinations is simple and gives healthy reproducible results. It should be of considerable utility to anyone interested in screening a wide variety of drug combinations for augmentation or synergistic effects.     

Accumulation of vincristine and doxorubicin in malignant lymphocytes with different immunophenotypes

Cellular accumulation of vincristine (VCR) and doxorubicin (DOX) was studied in 15 patients with low-grade B-cell malignancies. Their leukemic lymphocytes were isolated and the effect of verapamil on drug uptake was studied. The immunophenotype was characterized using anti-IgM, -IgD, -B 1, monoclonal antibodies. The more that cells bound the IgD or B1 antibodies, the more vincristine and doxorubicin did they accumulate. The fewer the cells that bound IgM antibodies, the more drug did they accumulate.     

Kinetic analysis of hepatobiliary transport of vincristine in perfused rat liver. Possible roles of P-glycoprotein in biliary excretion of vincristine.

Recent studies using bile canalicular membrane vesicles have suggested that P-glycoprotein may play a role in excreting some anticancer drugs from the liver to the bile. At steady state after a continuous single-pass perfusion of a tracer concentration of [3H]vincristine in the rat liver, the extraction ratio was approximately 0.6, and 70% of the extracted drug was excreted into the bile mostly in unchanged form. The liver/perfusate and bile/liver unbound concentration ratios obtained after correction for intracellular binding and the inside-negative membrane potentials and/or pH difference between the inside and outside of the cells, were approximately 2-3 and 160-280, respectively, suggesting a highly concentrated biliary excretion process. We also examined the effects of verapamil, a P-glycoprotein-related transport inhibitor in cancer cells, on the hepatobiliary transport of [3H]vincristine. Verapamil 50 microM in the perfusate caused a decrease in the biliary excretion rate of [3H]vincristine, whereas [14C]taurocholate (reference compound) remained constant. In contrast, the hepatic uptake rate of [3H]vincristine exhibited minimum reduction, suggesting that verapamil selectively inhibited the biliary excretion of [3H]vincristine at the canalicular membrane. The fact that verapamil had little effect on the initial velocity of [3H]vincristine uptake by isolated hepatocytes also supports the above findings. Since the effect of 150 microM verapamil in the perfusate was not selective for vincristine, the biliary excretion rates of both compounds ([3H]vincristine, [14C]taurocholate) were reduced by this concentration of verapamil. In conclusion, the concentrative excretion of vincristine into the bile and its selective inhibition by a moderate concentration of verapamil provide indirect evidence for the contribution of P-glycoprotein to the biliary excretion of vincristine in a perfused rat liver system.     

Application of cytogenetic endpoints and Comet assay on human lymphocytes treated with vincristine in vitro

The genotoxic potential of vincristine is assessed on human peripheral blood lymphocytes following administration of the drug at a dose 0.0875 microg/ml by use of single cell gel electrophoresis - Comet assay (SCGE), analysis of structural chromosome aberrations (CA), micronucleus assay (MN) and sister chromatid exchange (SCE) analysis. In vitro treatment of human lymphocytes with vincristine was performed on cells in G0 phase, as well on lymphocyte cultures 24 hours after stimulation with mitogen phytohemagglutinine. For the Comet assay at 24, 48 and 72 h the treated cells were embedded in agarose on slides, lysed with alkaline lysis solution and exposed to an electric field. DNA migrated within the agarose and formed comets whose length depends on the amount of DNA damage. For the analysis of structural CA cells were grown on F-10 medium for 48 hours, and for MN and SCE analysis for 72 hours. The results on SCGE showed an increase in tail length compared to control both in cells treated in G0 and in cells treated 24 h after mitogen stimulation. The amount of DNA damage was higher in cells treated with vincristine 24 h after mitogen stimulation. Administered concentration of drug caused total inhibition of lymphocytes growth in 72-h cultures for MN and SCE analysis indicating strong microtubule distruptive effects of vincristine. Analysis of structural CA reveals chromatid breaks and acentric fragments as the main aberration types both in cells treated in G0 and in cells treated 24 h after mitogen stimulation. Number of these aberrations was higher in cells treated in G0 phase. Results obtained in this study by use of different cytogenetic endpoints confirmed that vincristine exhibits both aneugenic and clastogenic effects on human lymphocytes.     

Acute vincristine neurotoxicity in a non-Hodgkin's lymphoma patient with Charcot-Marie-Tooth disease]

A 44-year-old, previously healthy man with a diagnosis of non-Hodgkin's lymphoma (NHL, diffuse large B-cell type, stage IIA) was treated with combination chemotherapy including vincristine (VCR). After receiving a cumulative dose of VCR, he experienced rapid and marked weakening which progressed to quadriplegia and bulbar palsy. Prior to this therapy, the patient had no neurological problems, and his siblings were asymptomatic. Physical examination identified pes cavus (hollow foot), and electrodiagnostic studies showed markedly slower nerve conduction velocity of myelinated fibers, with abundant "onion bulb" formations. Chromosomal analysis detected 17p11.2-12 duplication, thus yielding a diagnosis of Charcot-Marie-Tooth (CMT) 1A. CMT disease is a familial neuromuscular disorder, and the incidence is approximately 1 in 2,500. We concluded that if CMT disease is diagnosed, vincristine should be avoided due to the potential severity of neurotoxicity to small doses.