Biomedical subjects

D M Shin

Publications and source records attributed to D M Shin.

At least 19 recordsLinked to original sources

PubMed1999

Adenovirus-mediated p53 gene transfer in advanced non-small-cell lung cancer.

BACKGROUND: Preclinical studies in animal models have demonstrated tumor regression following intratumoral administration of an adenovirus vector containing wild-type p53 complementary DNA (Ad-p53). Therefore, in a phase I clinical trial, we administered Ad-p53 to 28 patients with non-small-cell lung cancer (NSCLC) whose cancers had progressed on conventional treatments. METHODS: Patients received up to six, monthly intratumoral injections of Ad-p53 by use of computed tomography-guided percutaneous fine-needle injection (23 patients) or bronchoscopy (five patients). The doses ranged from 10(6) plaque-forming units (PFU) to 10(11) PFU. RESULTS: Polymerase chain reaction (PCR) analysis showed the presence of adenovirus vector DNA in 18 (86%) of 21 patients with evaluable posttreatment biopsy specimens; vector-specific p53 messenger RNA was detected by means of reverse transcription-PCR analysis in 12 (46%) of 26 patients. Apoptosis (programmed cell death) was demonstrated by increased terminal deoxynucleotide transferase-mediated biotin uridine triphosphate nick-end labeling (TUNEL) staining in posttreatment biopsy specimens from 11 patients. Vector-related toxicity was minimal (National Cancer Institute's Common Toxicity Criteria: grade 3 = one patient; grade 4 = no patients) in 84 courses of treatment, despite repeated injections (up to six) in 23 patients. Therapeutic activity in 25 evaluable patients included partial responses in two patients (8%) and disease stabilization (range, 2-14 months) in 16 patients (64%); the remaining seven patients (28%) exhibited disease progression. CONCLUSIONS: Repeated intratumoral injections of Ad-p53 appear to be well tolerated, result in transgene expression of wild-type p53, and seem to mediate antitumor activity in a subset of patients with advanced NSCLC.

Adenoviridae↗

PubMed1999

Biochemoprevention for dysplastic lesions of the upper aerodigestive tract.

OBJECTIVES: To evaluate the efficacy and secondarily the toxic effects of biochemopreventive therapy (high-dose isotretinoin [13-cis-retinoic acid], alpha-tocopherol, and interferon alfa) in the reversal of advanced premalignant lesions of the upper aerodigestive tract and to correlate the therapeutic events with modulation of biomarkers. DESIGN: Prospective, nonrandomized chemoprevention trial. SETTING: Tertiary cancer care referral center and ambulatory care. PARTICIPANTS: Thirty-six patients with advanced premalignant lesions of the upper aerodigestive tract, without cancer during the 2 years before the intervention, with evaluable lesions, and without retinoid therapy for 3 months before the trial. INTERVENTION: Administration of oral isotretinoin (100 mg/m2 per day), oral alpha-tocopherol (1200 IU/d), and subcutaneous interferon alfa (3 megaunits per square meter twice weekly) for 12 months, with serial biopsies and clinical examination at 0, 6, 12, and 18 months from study start. MAIN OUTCOME MEASURES: Clinical and histologic responses to the intervention. RESULTS: Of the 36 patients, evaluation was possible in 30 for response at 6 months and in 21 at 12 months. At 6 months, there were 10 pathologic complete responses and 7 partial responses; at 12 months, 7 complete and 3 partial responses. A striking difference in response was observed in favor of laryngeal lesions (9/19 [47%] complete response rate at 6 months and 7/14 [50%] at 12 months vs 1/11 [9%] and 0/7 [0%], respectively, for oral lesions). Toxic effects were acceptable and did not exceed grade 3. CONCLUSION: Biochemoprevention is a promising biologic approach for laryngeal dysplasia and needs to be investigated further.

Adult↗

PubMed1999

Paclitaxel-based chemotherapy for recurrent and/or metastatic head and neck squamous cell carcinoma: current and future directions.

Head and neck squamous cell carcinoma (HNSCC) is a devastating tumor, with enormous repercussions both for the medical system and for the individual patient. Functional and cosmetic morbidity are inherent in head and neck cancer and its treatment, and the economic costs associated with the aggressive therapy needed to battle the disease are substantial. Even with aggressive standard local therapy (surgery and/or radiotherapy), the tumor recurs in approximately 60% of patients with primary disease and the prognosis for those whose disease recurs or metastasizes is poor. In light of these facts, trials of new therapy for recurrent and/or metastatic HNSCC must focus on prolonging survival, improving quality of life, and increasing convenience. The introduction in the 1990s of newer agents such as ifosfamide and the taxanes (paclitaxel [Taxol; Bristol-Myers Squibb Company, Princeton, NJ] and docetaxel) offers hope that these goals can be achieved. All are active against HNSCC and the taxanes, in particular, appear likely to be the most active single agents yet for treating recurrent and/or metastatic HNSCC. This report reviews experience with paclitaxel-based treatment regimens in HNSCC.

Antineoplastic Agents, Phytogenic↗

PubMed1999

A pilot clinical laboratory trial of paclitaxel and endobronchial brachytherapy in patients with non-small cell lung cancer.

Paclitaxel enhances microtubule assembly and causes a cell cycle arrest in mitosis, the most radiosensitive phase. We conducted this study to improve our understanding of paclitaxel effects in vivo and to determine the maximum tolerated dose of paclitaxel preceding endobronchial radiation therapy (brachytherapy). The treatment consisted of two cycles of paclitaxel infused over 24 hours followed by 192Ir brachytherapy; cycles were repeated every 3 weeks. Tumor samples were obtained at baseline, after each paclitaxel infusion, and 3 weeks after completion of therapy. Twenty-two non-small cell lung cancer patients with a documented endobronchial lesion were enrolled in the study and 20 patients received the therapy with different doses of paclitaxel, initially without and then later with granulocyte colony-stimulating factor (G-CSF) support (5 microg/kg subcutaneously on days 3 to 10). With the starting paclitaxel dose of 135 mg/m2, five of seven patients developed neutropenia and fever, which mandated a dose reduction to 120 mg/m2. At this dose level, three of three patients had neutropenic fever; thus, 120 mg/m2 of paclitaxel was considered above the maximum tolerated dose without G-CSF support. However, with G-CSF support the therapy was well-tolerated without dose-limiting toxicity and accrual is continuing at the paclitaxel 175-mg/m2 dose level. While no patient had achieved systemic tumor response, 11 patients achieved partial response of the endobronchial lesion, which represents 68.8% of 16 patients who received two courses of therapy and 91.8% of 12 patients who had full evaluation by bronchoscopy after completion of therapy. The in vivo paclitaxel effects were studied using the pre- and post-paclitaxel therapy tumor samples in eight patients. Four (50%) patients had a significant increase in mitotic cells after paclitaxel, as assessed by MPM-2 immunostaining that recognizes a large family of mitotic phosphoproteins. A substantial increase in the number of micronucleated apoptotic cells, another paclitaxel effect, was also found in six patients. These results clearly indicate that patients with endobronchial lesions from recurrent NSCLC could not tolerate this combined modality regimen without G-CSF support. However, this group of patients provided a unique opportunity to study in vivo paclitaxel effects in a clinical trial setting.

Aged↗

PubMed1999

P53 expression and polysomies of chromosome 9, 17 in head and neck cancer prognosis.

Sixty-nine cases of head and neck squamous cell carcinoma were examined by immunohistochemistry for p53 and chromosome in situ hybridization for chromosome 9 and 17 to determine the relationship between p53 expression and polysomies of chromosome 9 and 17 with the development of a second primary tumor as well as recurrence of primary tumor of head and neck squamous cell carcinoma. We found early expression of p53 in the normal and premaligant lesions adjacent to tumor which was associated with a gradual increase in the fraction of positive nuclei as well as numbers of cancer. We also found statistically significant increments of polysomies of chromosome 9 and 17 in terms of the polysomy index seen through the histologic changes occurring during multistep tumorigenesis. Our results could not demonstrate statistically significant correlation between p53 expression and PI 9 and 17 in tumorigenesis. Interestingly, however, there was a strong correlation between p53 expression and second primary tumor as well as recurrence of primary tumor. The p53 expressed group had a seven fold increased incidence in developing second primary tumor and a two and a half times increased incidence for recurrence of primary tumor, compared to the non-expressed group. We conclude that p53 expression and polysomies of chromosome 9 and 17 have an important role in multistep tumorigenesis in HNSCC. There was no significant correlation between p53 expression and polysomies of chromosome 9 and 17. However, the expression of p53 was statistically significant for association with second primary tumor and recurrence of primary tumor of head and neck squamous cell carcinoma.

Carcinoma, Squamous Cell↗

PubMed1998

Phenotype and genotype of advanced premalignant head and neck lesions after chemopreventive therapy.

BACKGROUND: The goal of chemoprevention is to reduce the risk of cancer development by reversing or blocking the tumorigenic process through the use of pharmacologic or natural agents. To determine the potential role of genetic alterations in assessing cancer risk and in evaluating the efficacy of chemopreventive agents, we studied 22 patients with advanced premalignant lesions of the head and neck who were part of a prospective cancer prevention trial that is investigating a regimen of 13-cis-retinoic acid, interferon alfa, and alpha-tocopherol administered for 12 months or until disease progression. METHODS: We used polymerase chain reaction analysis of microsatellite DNA sequences in cells from precancerous lesions to determine the frequencies of genetic alterations--namely, loss of heterozygosity (LOH) and microsatellite instability--at chromosomal loci that are commonly deleted in head and neck cancer. RESULTS: Prior to treatment, 17 (81%) of 21, eight (44%) of 18, and eight (42%) of 19 patients who were informative (i.e., heterozygous) at chromosomes 9p21, 3p14, and 17p13, respectively, exhibited LOH in at least one of their lesion biopsy specimens. Among nine patients who exhibited LOH at chromosome 9p21 in pretreatment biopsy specimens and who had completed at least 5 months of therapy, the genetic loss persisted in eight--including three of the four patients who exhibited complete histologic responses (i.e., no evidence of dysplasia in their biopsy specimens). IMPLICATION: Our data suggest that clinical and histologic assessments of the response to chemopreventive agents may be insufficient to determine their efficacy and that critical genetic alterations could be used as independent biomarkers to augment the ability to evaluate the efficacy of such agents.

Antineoplastic Agents↗

PubMed1998

A multidisciplinary approach to therapy for unresectable malignant thymoma.

BACKGROUND: The therapeutic outcome for unresectable, locally advanced, malignant thymoma has been poor. OBJECTIVE: To improve tumor resectability and patient survival rates by studying a multimodal approach to therapy for unresectable malignant thymoma. DESIGN: Prospective cohort study. SETTING: Tertiary care cancer center. PARTICIPANTS: All eligible patients had newly diagnosed, histologically proven, unresectable malignant thymoma. INTERVENTION: The treatment regimen consisted of induction chemotherapy (three courses of cyclophosphamide, doxorubicin, cisplatin, and prednisone), surgical resection, postoperative radiation therapy, and consolidation chemotherapy (three courses of cyclophosphamide, doxorubicin, cisplatin, and prednisone). Tissue samples were taken at the time of surgical resection for assessment of tumor necrosis and Ki-67 expression. MEASUREMENTS: Tumor response and resectability (both overall and after induction chemotherapy) and disease-free survival rate in patients who received multimodal therapy. RESULTS: 13 patients were consecutively enrolled from February 1990 to December 1996, and 12 evaluable patients were assessed for response. Disease responded to induction chemotherapy completely in 3 patients (25%) and partially in 8 patients (67%); 1 patient had a minor response (8%). Eleven patients had surgical resection; 1 refused surgery. Tumors were removed completely in 9 (82%) and incompletely in 2 (18%) of 11 patients who had been receiving radiation therapy and consolidation chemotherapy. All 12 patients are alive (100% at 7 years), with a median follow-up of 43 months, and 10 patients are disease free (73% disease-free survival at 7 years). A high correlation was seen between tumor necrosis after induction chemotherapy and Ki-67 expression (r=-0.88). CONCLUSIONS: Aggressive multimodal treatment is highly effective and may cure locally advanced, unresectable malignant thymoma.

Adult↗

PubMed1998

Cisplatin, ifosfamide, and prolonged oral etoposide in the treatment of patients with extensive small cell lung carcinoma.

BACKGROUND: The combination of cisplatin, ifosfamide, and prolonged oral etoposide (PIE) was studied in patients with extensive small cell lung carcinoma (SCLC) in a Phase I trial followed by a Phase II trial to determine the maximum tolerated dose (MTD), characterize toxicity, and estimate response and median survival rates. METHODS: Thirty-three patients were treated between October 1991 and December 1994. Doses for the initial cohort were cisplatin 20 mg/m2/day, ifosfamide 1500 mg/m2/day with mesna (all given intravenously on Days 1-3), and oral etoposide 50 mg/m2 on Days 4-17. This cycle was repeated every 4 weeks for up to 6 cycles. The MTD was reached for the first 9 patients. For these 9 patients and the next 24 patients, who were entered in the Phase II trial, response and survival were estimated. RESULTS: Dose-limiting toxicity was manifested as Grade 4 neutropenia in 3 of 3 patients (associated with fever in 2 of 3), and Grade 4 thrombocytopenia was encountered in 2 of 3 patients at the second dose level. Of 6 patients treated at the first dose level, 4 achieved targeted myelosuppression (absolute granulocyte count nadir <1000), but only 1 experienced Grade 4 neutropenia, defining this level as the MTD. Grade 4 neutropenia and/or thrombocytopenia was observed in 36 (24%) of a total of 152 courses administered at or below the MTD. Nonhematologic toxicity above Grade 2 was uncommon, excluding nausea and vomiting. Overall objective response rate was 93% of 30 evaluable patients: 5 (17%) complete responses and 23 partial responses (76%). Median failure free and overall survival durations were 36 and 54 weeks, respectively. CONCLUSIONS: The combination of cisplatin, ifosfamide, and oral etoposide produced encouraging failure free and overall median survival rates in patients with extensive SCLC. These results warrant further evaluation of this regimen in the initial therapy of patients with limited stage disease.

Administration, Oral↗

PubMed1998

Integration of filgrastim into chemoradiation for limited small cell lung cancer: a Phase I study.

PURPOSE: Recent studies document the value of early combined modality therapy of small cell lung cancer, but also indicate that early thoracic radiation adds to myelosuppression and can complicate further chemotherapy. Other studies indicate that simultaneous use of growth factors with thoracic radiation may be deleterious. However, temporal separation of growth factor use from cytotoxic therapy may allow dose intensity to be maintained/enhanced during combined modality treatment. We sought to integrate filgrastim into a novel chemoradiation regimen for patients with limited small cell lung cancer using an approach that separated growth factor administration from both chemotherapy and thoracic radiation. METHODS AND MATERIALS: Twenty-seven patients with limited disease small cell lung cancer were enrolled in a Phase I trial of cisplatin, ifosfamide/mesna, oral etoposide, and thoracic radiation (1.5 Gy b.i.d. x 30 fractions days 1-19 cycle 1) +/- filgrastim (5 microg/kg/day). Filgrastim was given on days 20-25 of cycle 1 after completion of radiation and following completion of oral etoposide in subsequent cycles. The primary end point was determination of maximum tolerated dose (MTD) of chemotherapy. Serial cohorts were treated with and without filgrastim. RESULTS: Because of dose-limiting thrombocytopenia, primarily, and nonhematologic toxicity, the MTDs with and without filgrastim were identical (cisplatin 20 mg/m2 i.v. and ifosfamide 1200 mg/m2 i.v., both given days 1-3, and etoposide 40 mg/m2 p.o. days 1-14). Filgrastim use shortened the duration of neutropenia at the MTD (median 4 vs. 7 days), but was not associated with a reduction in febrile neutropenia. Although growth factor administration did not allow dose escalation of this regimen, it did allow chemotherapy doses to be maintained at the MTD more frequently through four cycles of therapy. In the 24 evaluable patients, the overall response rate was 100% (71% partial and 29% complete). CONCLUSIONS: Despite careful attention to the timing of growth factor with chemoradiation, the administration of filgrastim with this regimen did not allow dose escalation. As in many other recent studies of hematopoietic growth factors given prophylactically with chemotherapy, the duration of neutropenia at the MTD was shortened and the need for dose reduction throughout treatment was reduced in patients receiving filgrastim at the MTD.

Adult↗

PubMed1998

Unusual presentation of mycosis fungoides as pigmented purpura with malignant thymoma.

Thymoma is known to be associated with many lymphoreticular and nonlymphoreticular tumors. A woman who presented with patch stage mycosis fungoides with skin lesions resembling a pigmented purpura was found to have an anterior mediastinal mass on routine staging evaluation. A core needle biopsy of the mass revealed a lymphocyte predominant malignant thymoma. Review of the literature reveals many diseases with dermatologic manifestations associated with thymoma; however, malignant thymoma coexisting with mycosis fungoides has not previously been reported.

Adult↗

PubMed1998

Phase II trial of recombinant IFN-alpha2a with etoposide/cisplatin induction and interferon/megestrol acetate maintenance in extensive small cell lung cancer.

Previous data suggested interaction of cisplatin with interferon (IFN) in non-small cell lung cancer and a possible effect of IFN in maintaining remission in small cell lung cancer (SCLC). This study was designed to further examine the effect of IFN in the treatment of extensive disease (ED) SCLC. Forty previously untreated patients with performance status (PS) of 0-2 (Zubrod scale) were treated with etoposide (100 mg/m2 for 3 days), cisplatin (25 mg/m2 for 3 days) (EP), and recombinant IFN-alpha2a (rIFN-alpha2a) (5 x 10(6) U/m2 for 3 days) for six cycles (induction), followed by rIFN-alpha2a (5 x 10(6) U/m2) thrice weekly and megestrol acetate (40 mg q.i.d.) as maintenance therapy for 6 months or until progressive disease or intolerable toxicity was documented. Patients were 25 men (62%) and 15 women (38%), median age 58 (28-76), median Zubrod performance status 1 (0-2). Major sites of metastasis include liver (55%), bone (42%), bone marrow (25%), and adrenal gland (18%). Of 40 eligible patients accrued to this trial, 35 were evaluable for response, and 37 were evaluable for toxicity. There were 3 complete and 28 partial responses, for an overall response rate of 89%. With 39 of 40 patients followed until death, median survival (Kaplan-Meier) is estimated at 46 weeks (95% CI range 35-55). Twenty patients completed six cycles of induction, and 16 received maintenance therapy, median 2 cycles (range 1-3). Major toxicity during induction included grade 4 granulocytopenia in 24%, grade 2-3 nausea or vomiting or both in 41%, grade 2 fatigue in 24%, grade 2 anorexia in 22%, and grade 2-3 renal insufficiency in 9% of 175 total courses of chemotherapy administered. Toxicity during the maintenance phase was notable for grade 2-3 fatigue in 43%, grade 2-3 anorexia in 24%, grade 2-3 weight loss in 10%, and grade 3-4 anemia in 17% of 30 courses. There were no treatment-related deaths. The addition of rIFN-alpha2a to EP in induction chemotherapy of ED SCLC, followed by rIFN-alpha2a and megestrol acetate maintenance therapy, was reasonably well tolerated. The complete and overall response rates and duration of remission and survival appear to be similar to those generally obtained with EP alone in similar patients.

Adult↗

PubMed1998

Phase II trial of paclitaxel, ifosfamide, and cisplatin in patients with recurrent head and neck squamous cell carcinoma.

PURPOSE: To assess the activity and toxicity profile of combined taxol (paclitaxel), ifosfamide, and platinum (cisplatin) (TIP) in patients with recurrent or metastatic squamous cell carcinoma (SCC) of the head and neck. PATIENTS AND METHODS: Recurrent or metastatic head and neck SCC patients received paclitaxel 175 mg/m2 in a 3-hour infusion on day 1; ifosfamide 1,000 mg/m2 in a 2-hour infusion on days 1 through 3; mesna 600 mg/m2 on days 1 through 3; and cisplatin 60 mg/m2 on day 1, repeated every 3 to 4 weeks. All were premedicated with dexamethasone, diphenhydramine, and cimetidine. Prophylactic hematopoietic growth factors were not permitted. RESULTS: Fifty-two patients were assessable for response and toxicity; 53 for survival (local-regional recurrence alone in 57% and distant metastasis with or without local-regional recurrence in 43%). Overall response rate was 58% (30 of 52) of patients; complete response rate was 17% (nine of 52) of patients, with six complete responses that continued for a median 15.7+ months. Median follow-up of all patients was 17.7 months. Median survival was 8.8 months (95% confidence interval [CI] 8.1 to 17.5 months). Toxicity was relatively well tolerated and caused no deaths. The most frequent moderate-to-severe toxicity (90% of patients) was transient grades 3 to 4 neutropenia; neutropenic fever occurred in 27%. Grade 3 peripheral neuropathy occurred in three patients, none had grade 4. Grade 3 mucositis occurred in only one patient, none had grade 4. CONCLUSION: TIP had major activity in this setting, with a 58% objective response rate, 17% complete response rate, durable complete responses (six of nine persisting), and relatively well-tolerated toxicity, with no toxic deaths. The activity of TIP, a novel taxol-cisplatin-based regimen, in recurrent or metastatic head and neck SCC should be confirmed in a phase III trial.

Adult↗

PubMed1998

Role of paclitaxel, ifosfamide, and cisplatin in patients with recurrent or metastatic squamous cell carcinoma of the head and neck.

This phase I/II study investigated the efficacy and toxic effects of combination chemotherapy using paclitaxel (Taxol; Bristol-Myers Squibb Company, Princeton, NJ), ifosfamide, and cisplatin (TIP) in patients with recurrent or metastatic squamous cell carcinoma of the head and neck. Twelve patients were entered in the phase I part of the study, results of which were reported previously. Fifty-three patients were treated in the phase II part of the study with 175 mg/m2 paclitaxel in a 3-hour infusion on day 1; 1,000 mg/m2/d ifosfamide in a 2-hour infusion on days 1 to 3; and 60 mg/m2 cisplatin on day 1, repeated every 3 to 4 weeks. Thirty-five men and 18 women were treated; the median age was 55 years (range, 27 to 73 years). Sites of disease and types of previous therapy varied among the patients. Among those with recurrent disease, 30 had locoregional disease, four had locoregional disease with distant metastasis, and 17 had distant metastasis only. Two patients had distant metastatic disease (MI) at the time of diagnosis. Of the 53 patients entered, 52 were assessable for disease response and toxic effects. Complete response was achieved in nine (17%) of 52 patients and partial response in 21 (40%); five (10%) patients had stable disease and 17 (33%) had progressive disease. When response rate was analyzed by disease sites, patients with locoregional sites showed a 43% major response (complete and partial) rate, and those with distant metastatic sites demonstrated an 80% major response rate (P=.04). The median duration of disease response in all patients was 4.9 months at completion of the study. Among the nine patients with complete response, three had progressive disease and the median duration of response was 6.9 months (range, 4.9 to 17 months); six were still in remission at the time of this writing, with a median duration of response of 12.8 months (range, 6.3 to 18.8+ months). The median survival time was 8.8 months, and the 1- and 2-year survival rates were 40% and 21.9%, respectively. The median follow-up time of the study was 11.8 months. The major toxic effects included neutropenia, cumulative peripheral neuropathy, and fatigue. Mucositis was rare; grade 3 mucositis developed in only one patient. Other side effects included neutropenic fever in 14 patients, all of whom completely recovered after antibiotic treatment. Grade 3 orthostatic hypotension and grade 3 peripheral neuropathy developed in one patient; supportive care led to gradual recovery. No deaths were caused by toxic effects. In conclusion, these preliminary results indicate that the TIP chemotherapy regimen produced high rates of major responses in patients with recurrent or metastatic head and neck squamous cell carcinoma, and responses were durable. The median, 1-year, and 2-year survival times were particularly promising. The TIP regimen should be pursued further as an induction regimen for locally advanced head and neck cancer.

Adult↗

PubMed1998

Gene therapy for non-small cell lung cancer: a preliminary report of a phase I trial of adenoviral p53 gene replacement.

The identification of genetic lesions that lead a normal cell to become malignant presents us with the opportunity of targeting those lesions as a means of therapy. Given the key role played by the tumor suppressor gene p53 in cell cycle regulation and apoptosis, and the evidence linking p53 mutations with non-small cell lung cancer, attempts at p53 replacement are a logical approach to therapy in this disease. In a phase I study, administration of an adenoviral p53 vector (Adp53) to 21 patients with advanced non-small cell lung cancer produced little toxicity. Up to six intratumoral injections at monthly intervals were well-tolerated. Expression of the p53 transgene was evident, along with potentially useful clinical responses. Time to disease progression in the indicator lesion treated with Adp53 appears to be enhanced by higher doses of vector, concomitant cisplatin therapy, and evidence of apoptosis on tumor biopsy specimens. Phase II trials should now be undertaken to determine the response rate to Adp53.

Adenoviridae↗

PubMed1998

Staurosporine-induced Ca2+ mobilization in rat mandibular salivary acini.

The effect of the protein kinase C inhibitor, staurosporine, on intracellular Ca2+ homeostasis was investigated in rat mandibular salivary acinar cells loaded with fura-2. Fura-2 fluorescence was measured at 510 nm while the excitation wavelength was alternated between 340 nm and 380 nm. The ratio of fluorescence intensity (F(340/380)) was used as an index of [Ca2+]i. Stimulation of acinar cells with 10 microM carbachol (CCh) induced a rapid increase in F(340/380) followed by a slow decrease to a sustained elevated level. Addition of 1 microM staurosporine in the presence of CCh caused a further increase in F(340/380). In order to examine whether the staurosporine-induced increase in F(340/380) could be attributed either to the Ca2+ entry pathway or to the mobilization of Ca2+ from intracellular Ca2+ stores, 1 microM staurosporine was added in the presence of CCh after Ca2+ had been omitted from the perfusate. Even in the absence of extracellular Ca2+, F(340/380) still increased slowly from 0.75 +/- 0.05 to 1.57 +/- 0.24 after a delay ranging between 5 min and 10 min. However, the IP3-sensitive intracellular Ca2+ stores did not seem to play a major role in this phenomenon because staurosporine still increased F(340/380) by 0.6 +/- 0.10 after the complete depletion of IP3-sensitive Ca2+ stores by the exposure of cells to 1 microM thapsigargin, a microsomal Ca2+ ATPase inhibitor, in Ca2+-free conditions. These results suggest that staurosporine mobilizes Ca2+ from IP3-insensitive intracellular Ca2+ stores in rat mandibular salivary acinar cells.

Animals↗

PubMed1997

Thymic neoplasms.

Thymomas are infrequent and relatively indolent mediastinal tumors. They are usually encapsulated and readily removed. Invasive tumors, even if completely resected, require additional therapy. Although efforts have been made to relate histopathologic characteristics to outcome, the most important prognostic factors are stage and ability to achieve complete resection. The responsiveness of these tumors to chemotherapy and radiation therapy has led to combining all three modalities in a consistent sequence to derive maximal benefit from each to outcome in patients with locally advanced stage tumors.

Humans↗

PubMed1997

Maximum-tolerated dose defined for single-agent gemcitabine: a phase I dose-escalation study in chemotherapy-naive patients with advanced non-small-cell lung cancer.

PURPOSE: We conducted a phase I trial of the novel nucleoside analog, gemcitabine, in chemotherapy-naive patients with advanced non-small-cell lung cancer (NSCLC) to determine the maximum-tolerated dose and efficacy in this population. PATIENT AND METHODS: Eligibility requirements included stage III or IV NSCLC, performance status < or = 1, and no prior chemotherapy. Gemcitabine was administered as a 30-minute intravenous infusion weekly for 3 weeks every 4 weeks. We enrolled patients at doses that ranged from 1,000 to 2,800 mg/m2/wk (three patients per cohort). Responses were assessed after every two courses (8 weeks). RESULTS: We treated 33 chemotherapy-naive patients with stage III (n = 5) or IV (n = 28) NSCLC. Most had performance status 1, and 67% had adenocarcinoma. Eight of 32 assessable patients (25%) achieved a partial response. The projected median survival duration (all patients) is 49 weeks. The maximum-tolerated dose was 2,200 mg/m2/wk for 3 weeks every 4 weeks; dose-limiting toxicity was myelosuppression and reversible transaminase elevation. Other side effects were consistently mild. The maximum dose-intensity achieved with the first two cycles was 2,362 mg/m2/wk for 3 weeks every 4 weeks, which is a feasible phase II starting dose. CONCLUSION: This study estimates a phase II starting dose of gemcitabine in chemotherapy-naive patients to be 2,400 mg/m2/wk for 3 consecutive weeks every 4 weeks; this is much higher than that previously reported in heavily pretreated patients. Twenty-five percent of patients with advanced NSCLC achieved a partial response to gemcitabine. This significant activity in conjunction with a very favorable toxicity profile supports the further evaluation of gemcitabine in combination with other active agents.

Adult↗

PubMed1997

Biomarkers of squamous cell carcinoma of the head and neck.

Despite the remarkable advances in cancer treatment, the 5-year survival rate for head and neck squamous cell carcinoma (HNSCC) has improved only marginally over the past 20 years. Investigators have attempted to develop new therapeutic methods to improve the survival rate from these tumors. Another approach, chemoprevention, has recently been tried to reduce cancer incidence. Biological understanding of tumorigenesis is critically important to provide risk assessment and intermediate end points during chemoprevention trials. Based on the fact that HNSCC develops through a multistep process by the accumulation of genetic and phenotypic changes in the field exposed to carcinogens, the investigation of specific biomarkers that represent each step must be valuable, since these biomarkers could be used to inhibit and/or to reverse the pathway of carcinogenesis. The potential biomarkers are classified as nonspecific and specific genetic biomarkers, proliferation markers, and differentiation markers in this review. Their usefulness in predicting tumors' biological behavior and responses to treatment and in monitoring the preventive effects of chemoprevention trials is also discussed.

Biomarkers, Tumor↗