Ram P. Agarwal

A phase I study of recombinant human interferon-alpha 2a or human lymphoblastoid interferon-alpha n1 and concomitant zidovudine in patients with AIDS-related Kaposi's sarcoma.

To determine the safety, maximum tolerated dose, and preliminary efficacy of concomitant interferon-alpha and zidovudine therapy in AIDS-related Kaposis sarcoma (KS), 56 patients with biopsy-proven KS and documented human immunodeficiency virus type 1 (HIV) infection were enrolled into a phase I study. Interferon-alpha was given intramuscularly at a dose of 9, 18, or 27 mu once a day and zidovudine was administered as 100 or 200 mg every 4 h for 8 weeks followed by a 48-week maintenance period. The major toxicities were anemia, neutropenia, and hepatotoxicity. Neutropenia was dose limiting with 1,200 mg of zidovudine/day and the lowest dose of interferon-alpha (9 mu/day). Hepatotoxicity was dose limiting with 27 mu of interferon and 600 mg of zidovudine/day. Cumulative dose-related anemia or neutropenia was not seen during long-term follow-up. The maximum tolerated doses for the combination were defined as 18 mu daily for interferon-alpha and 600 mg daily for zidovudine. Variable changes in CD4 lymphocytes occurred during the first 8 weeks of therapy. At higher doses of the combination, sustained increases in median CD4 lymphocyte numbers were noted (p less than 0.001). In HIV antigenemic patients, progressive antigen suppression was seen with increasing doses of the combination (p less than 0.005). The overall antitumor response rate was 47%. Tumor regression was associated with better survival benefits (p less than 0.001) and a pretreatment CD4 cell count greater than or equal to 200 cells/mm3 (p = 0.01). In conclusion, intermediate doses of interferon-alpha and lower doses of zidovudine appear to be relatively well tolerated and associated with disease improvement, including survival benefits.

Peripheral-type benzodiazepines inhibit proliferation of astrocytes in culture

Peripheral-type benzodiazepine (BZD) receptors have been identified in brain and are predominantly localized to astrocytes. To determine their potential role in controlling astroglial proliferation, DNA synthesis, growth curves and mitotic index were investigated in primary astrocyte cultures which had been exposed to Ro5-4864 (a peripheral-type BZD ligand) and PK11195 (a peripheral-type BZD receptor antagonist). There was a dose-dependent inhibition of mitosis when two-week-old cells in culture were exposed to 50 nM, 500 nM, 1 microM and 10 microM Ro5-4864 for 24 h. Exposure of 5-, 8-, 12- and 15-day-old cultures to Ro5-4864 and PK11195 for 24 h did not affect growth rate and DNA synthesis; however, continuous exposure to 10 microM Ro5-4864 caused a persistent inhibition of cell growth and [3H]thymidine incorporation (P less than 0.05) while nanomolar concentrations did not cause any significant change. Concurrent administration of Ro5-4864 with PK11195 resulted in a partial reversal of Ro5-4864-induced inhibition in DNA synthesis and mitosis. These results indicate that peripheral-type BZDs are capable of inhibiting proliferation of astrocytes in culture.

Phase I clinical trial and pharmacokinetics of weekly ICRF-187 (NSC 169780) infusion in patients with solid tumors

ICRF-187 was given to 62 evaluable patients with advanced solid tumors in a Phase I clinical trial. Weekly infusions were given in dosages ranging from 0,85 g/m2 to 7.42 g/m2 for a total of four weeks with a two week rest period between courses. Dose-limiting hematological toxicity was seen in heavily pretreated patients at a dose of 3.8 g/m2/week. All patients also developed reversible SGOT elevations. In patients with less prior therapy hematologic toxicity was not dose-limiting but hepatotoxicity, manifest by transient SGOT levels greater than 5 times baseline was seen at 7.42 g/m2/week even though only 3/6 patients could receive 4 consecutive weekly doses. At virtually all dose levels tested some patients developed anemia. Other toxicities, including alopecia, nausea, vomiting and reversible serum amylase elevations, were mild.Cumulative monthly doses achieved on this weekly schedule are significantly higher than a 48-hour infusion or daily times 3 or 5 schedule in adults and a daily times 3 schedule in children. Pharmacokinetic studies in eight patients indicate that the drug disappears from the plasma biphasically with a terminal t1/2 of 3.2 +0.9 hr. The total clearance was 288.7 + 85.0 ml/hr/kg and the volume of distribution (Vda) was 1.3 ± 0.4 1/kg. Pharmacokinetics were not dose-dependent from 3.8–7.4 g/m2 and no difference in pharmacokinetics was found in patients studied during the first and second treatments of a course.If Phase II trials of ICRF-187 are to be pursued on this schedule, appropriate doses would be 3.8 g/m2/week × 4 for heavily pretreated and 7.42 g/m2/week for “good risk” patients. Because of erratic hematologic toxicity in heavily pretreated patients, some might only tolerate three weekly doses. In good risk patients transaminitis was significant but reversible, thus, Phase II protocols should include dose escalation schemata.

Anti-proliferative and anti-cancer properties of Achyranthes aspera: specific inhibitory activity against pancreatic cancer cells.

AIMS OF THE STUDY Achyranthes aspera (Family: Amaranthacea) is a medicinal plant used as an anti-cancer agent in ayurveda, a traditional system of medicine practiced in subcontinental India. The aim of the study was to systematically investigate the anti-proliferative properties of Achyranthes aspera leaves extracted in methanol (LE) on human cancer cells in vitro. MATERIALS AND METHODS We tested time, dose dependent and specific anti-proliferative activity of LE by clonogenic cell survival assay on human cancer and normal epithelial cell lines in vitro. We further investigated its effect on the expression of metastatic and angiogenic genes by real time polymerase chain reaction. On silica gel column, we carried out initial fractionation analysis. RESULTS LE exhibited time and dose dependent cytotoxicity on several tumor cells. Compared to cancer cells of colon, breast, lung and prostate origin, pancreatic cancer cells were significantly more sensitive to LE. Preliminary mechanistic studies suggested that LE selectively suppressed the transcription of metalloproteases (MMP-1 and -2), inhibitors of MMPs (TIMP-2) and angiogenic factors (VEGF-A and VEGF-B). Fractionation of LE on methanol equilibrated silica gel column resolved into three fractions of which fraction (F 3) was found to be enriched with anti-proliferative activity. CONCLUSION Methanolic extract of Achyranthes aspera contains potent anti-proliferative compound with specific activity against pancreatic cancer. Further studies are needed to confirm the in vivo anti-tumorigenicity and subsequent chemical characterization of the active molecule(s).

A phase i study of 4′-0-tetrahydropyranyladriamycin: Clinical pharmacology and pharmacokinetics

A Phase I study of intravenous (IV) bolus 4′‐0‐tetrahydropyranyladriamycin (Pirarubicin) was done in 55 patients in good performance status with refractory tumors. Twenty‐six had minimal prior therapy (good risk), 23 had extensive prior therapy (poor risk), and six had renal and/or hepatic dysfunction. A total of 167 courses at doses of 15 to 70 mg/m2 were evaluable. Maximum tolerated dose in good‐risk patients was 70 mg/m2, and in poor‐risk patients, 60 mg/m2. the dose‐limiting toxic effect was transient noncumulative granulocytopenia. Granulocyte nadir was on day 14 (range, 4–22). Less frequent toxic effects included thrombocytopenia, anemia, nausea, mild alopecia, phlebitis, and mucositis. Myelosuppression was more in patients with hepatic dysfunction. Pharmacokinetic analyses in 21 patients revealed Pirarubicin plasma T 1/2 α (± SE) of 2.5 ± 0.85 minutes, Tβ 1/2 of 25.6 ± 6.5 minutes, and T 1/2 γ of 23.6 ± 7.6 hours. the area under the curve was 537 ± 149 ng/ml × hours, volume of distribution (Vd) 3504 ± 644 l/m2, and total clearance (ClT) was 204 + 39.3 l/hour/m2. Adriamycinol, doxorubicin, adriamycinone, and tetrahydropyranyladriamycinol were the metabolites detected in plasma and the amount of doxorubicin was ⩽ 10% of the total metabolites. Urinary excretion of Pirarubicin in the first 24 hours was ⩽ 10%. Activity was noted in mesothelioma, leiomyosarcoma, and basal cell carcinoma. the recommended starting dose for Phase II trials is 60 mg/m2 IV bolus every 3 weeks.

Effects of Cyclic AMP and Butyrate on Cell Cycle, DNA, RNA, and Purine Synthesis of Cultured Astrocytes

Dibutyryl cyclic monophosphate (dBcAMP) has been shown to inhibit growth, and alter the morphology of astrocytes. However, the potential contribution of its hydrolytic product, butyrate, in inducing some of the changes that have been attributed to dBcAMP, is not clear. DNA, RNA, and purine synthesis were therefore studied in primary astrocyte cultures after 24 hours of exposure to varying concentrations of butyrate, dBcAMP, and agents that increase intracellular cAMP levels. Progression of cells through cell cycle was also studied by flow cytometry. Dibutyryl cAMP partially arrested cells in Go/G1 phase of cell cycle while sodium butyrate increased the percentage population of cells in G2/M phase. DNA synthesis and de novo purine synthesis were inhibited after treatment with dBcAMP, sodium butyrate, and various drugs that increase intracellular cAMP levels. RNA synthesis was increased with cAMP but was not affected by sodium butyrate. Our study shows that at millimolar concentrations, butyrate is capable of altering the cell cycle and inhibiting DNA synthesis in primary astrocyte cultures, in a manner that is similar although not identical to the effects of dBcAMP.

Arabinosylcytosine downregulates thymidine kinase and induces cross-resistance to zidovudine in T-lymphoid cells.

The aim of this study was to determine molecular mechanism(s) responsible for the reduced thymidine kinase activity (TK) observed earlier in an arabinosylcytosine (araC) resistant lymphoid cell line (H9-araC cells), which was obtained following continuous cultivation of H9 cells in the presence of 0.5 microM araC. Compared to H9 cells, in H9-araC cells TK1 and TK2 gene expressions were reduced to 17.7% and 2.5%, respectively, and the cellular AZT accumulation was diminished to 35.8%. These cells were also found cross-resistant to azidothymidine (>42-fold). There was no significant difference in the expression of MDR1, MRP4 or TK protein. The lack of correlation between the expressions of TK protein and TK1 and TK2 suggests that post-translational factors may also play a role in the reduced TK activity in H9-araC cells. These findings suggest that araC affects TK expression at the genetic level.

Effects of Methotrexate on RNA and Purine Synthesis of Astrocytes in Primary Culture

There is increasing evidence to indicate that astrocytes are primary targets for methotrexate (MTX) neurotoxicity. However, the mechanism by which MTX exerts its deleterious effect on astroglial cells is not known. Methotrexate acts by inhibiting dihydrofolate reductase and in other cell systems has been reported to inhibit thymidylate synthesis, purine synthesis or both. To determine the mechanism involved in MTX-induced toxicity to the nervous system, RNA synthesis was studied in two week-old primary astrocyte cultures by measuring [3H]Uridine (Urd) incorporation 24 hours after exposure to varying concentrations of MTX. De novo purine synthesis was also studied by measuring incorporation of [14C]glycine and [14C]formate in cultured astrocytes. The radioactivity level of incorporated Urd in culture decreased to 48%, 53% and 43% after exposure to 1, 10 and 100 μM MTX. Total [14C]glycine incorporation was not affected while incorporation of [14Qformate was almost completely inhibited by MTX. The MTX-induced inhibition of [3H]Urd incorporation was not reversed by concomitant addition of exogenous purine bases (1 and 10 üM adenine, guanine and hypoxanthine) or nucleosides (1 and 10 μM adenosine, guanosine and inosine) to the MTX-treated cultures. On the other hand, addition of formyl-tetrahydrofolate reversed the MTX-induced reduction in [3H]Urd incorporation, indicating that the RNA inhibition was due to depletion of folate-dependent substrates for purine synthesis. Our results provide evidence that inhibition of purine and RNA synthesis may be the underlying mechanism involved in MTX-induced injury to the astrocytes, and may be important in the pathogenesis of MTX encephalopathy.

Yoga into cancer care: A review of the evidence-based research

To cope with cancer and its treatment-related side effects and toxicities, people are increasingly using complementary and alternative medicine (CAM). Consequently, integrative oncology, which combines conventional therapies and evidence-based CAM practices, is an emerging discipline in cancer care. The use of yoga as a CAM is proving to be beneficial and increasingly gaining popularity. An electronic database search (PubMed), through December 15, 2016, revealed 138 relevant clinical trials (single-armed, nonrandomized, and randomized controlled trials) on the use of yoga in cancer patients. A total of 10,660 cancer patients from 20 countries were recruited in these studies. Regardless of some methodological deficiencies, most of the studies reported that yoga improved the physical and psychological symptoms, quality of life, and markers of immunity of the patients, providing a strong support for yogas integration into conventional cancer care. This review article presents the published clinical research on the prevalence of yogas use in cancer patients so that oncologists, researchers, and the patients are aware of the evidence supporting the use of this relatively safe modality in cancer care.

Effect of long-term zidovudine exposure on salvage and de novo purine and pyrimidine nucleotide syntheses

Salvage and de novo purine and pyrimidine nucleotide syntheses were studied in H9 (a human lymphoid cell line) and H9-AZT cells (chronically zidovudine-exposed H9 cells). H9-AZT cells incorporated 18% and 27% more hypoxanthine and uridine, respectively, than H9 cells. The incorporation of the formate and bicarbonate was similar in both cell lines. Purine and pyrimidine de novo synthesis was inhibited by hypoxanthine and uridine, respectively. Hypoxanthine and uridine salvage pathways, however, were not affected by formate or bicarbonate. Short-term AZT exposure of cells had no effect on nucleotide synthesis. Some of the problems encountered in the studies of purine and pyrimidine synthesis are also discussed.