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Biomedical subjects

M R Green

Publications and source records attributed to M R Green.

At least 73 records · Page 4Linked to original sources
PubMed1999

Radiosensitization with carboplatin for patients with unresectable stage III non-small-cell lung cancer: a phase III trial of the Cancer and Leukemia Group B and the Eastern Cooperative Oncology Group.

PURPOSE: To determine whether the administration of carboplatin concurrently with radiation treatment improves survival in patients with inoperable stage III non-small-cell lung cancer. PATIENTS AND METHODS: Two hundred eighty-three patients with inoperable stage III non-small-cell lung cancer were entered onto a randomized trial by the Cancer and Leukemia Group B and the Eastern Cooperative Oncology Group. Randomization was performed before initiation of any therapy. All patients received an induction chemotherapy program with vinblastine and cisplatin for 5 weeks, followed by 6,000 cGy of radiation therapy over 6 weeks. One hundred thirty-seven patients were randomized to this therapy regimen alone; 146 patients were randomized to receive carboplatin at 100 mg/m2/wk concurrent with the radiation therapy. RESULTS: The complete response was 18% with concurrent carboplatin versus 10% with radiotherapy alone (P = .101). There was no difference with respect to failure-free survival (10% with carboplatin and 9% with radiotherapy alone) or overall survival (13% with carboplatin and 10% with radiotherapy alone) at 4 years. In patients not receiving carboplatin, the relapse rate was 69% within the field of radiation and 53% in the boost volume. In patients receiving carboplatin, the relapse rate was 59% within the field of radiation and 43% in the boost volume. Patients with cancers more than 70 cm2 in size had significantly poorer survival (P = .01). CONCLUSION: Carboplatin at the dose and schedule used did not significantly impact on disease control or survival. The relapse rate within the chest remained more than 50%. More effective regimens will be required to impact on local disease control and survival.

Adult↗
PubMed1999

The 1997 International Staging System for non-small cell lung cancer: have all the issues been addressed?

The International Staging System for Lung Cancer has been revised recently. Important changes have been made to allow better correlation of prognoses and direction of management. The classification of synchronous pulmonary nodules in the same lobe as the primary tumor as T4 stage IIIB may imply a poorer outcome than is warranted, while the designation of a similar stage for malignant pleural effusion may not be reflective of the very poor prognosis associated with this extent of disease.

Carcinoma, Non-Small-Cell Lung↗
PubMed1999

Overview of MTA in the treatment of non-small cell lung cancer.

While advanced non-small cell lung cancer is a malignancy which remains largely refractory to chemotherapy, the 1990s have seen gains in both the number of agents available as well as the frequency of use of these agents in the treatment of non-small cell lung cancer. This report reviews several studies of MTA (multitargeted antifolate, LY23 1514), a novel antifolate, as first- and second-line treatment. MTA has been tested in advanced non-small cell lung cancer in a variety of patient populations, including those who have received no prior chemotherapy, those who have relapsed following prior platinum-containing therapy, and those who have relapsed following prior chemotherapy which did not contain platinum. In both groups MTA was found to be active, its activity in chemonaive patients was comparable (14%-23%) to currently used new drugs like taxanes and gemcitabine. Additionally, MTA has been studied in combination with cisplatin in patients who are chemotherapy-naive, with a response rate (42%) comparable to other modern combination regimens. Preliminary data appear promising and will be discussed.

Antineoplastic Agents↗
PubMed1999

Current strategies for locoregionally advanced unresectable non-small cell lung cancer.

Locoregionally advanced unresectable non-small cell lung cancer is defined by bulky primary site disease and/or regionally advanced lymphadenopathy involving the contralateral mediastinum and/or supraclavicular lymph nodes. These tumors are not amenable to curative-intent surgical resection but can be approached with curative-intent radiation therapy. It is clear, however, that when exposed to radiation therapy as a single treatment modality, the majority of patients will develop systemic disease progression, indicating the presence of systemic micrometastases at the time of initial diagnosis. It also has been demonstrated that a large percentage of patients will develop locoregional disease progression. The latter indicates the inability of standard fractionation radiation therapy to successfully eradicate the disease within the radiated field. It can be concluded that to truly eradicate the disease and achieve cure, more successful locoregional and systemic therapy has to be administered. The integration of chemotherapy with radiation therapy has been pursued in clinical trials over the last 20 years and is reviewed. The results of phase II trials investigating weekly administration of carboplatin, paclitaxel, and radiation therapy have been encouraging. Confirmation of their findings in the large cooperative group setting will be necessary.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1999

Single-agent gemcitabine and gemcitabine/irinotecan combination (irimogem) in non-small cell lung cancer.

Gemcitabine is a fluoridated pyrimidine related to cytosine arabinoside that has significant activity in solid tumor models. Irinotecan is a camptothecin analog with an active metabolite, SN-38, which inhibits topoisomerase I activity by stabilizing the topoisomerase I-DNA cleavable complex. Gemcitabine studies in non-small cell lung cancer conducted in the United States, as well as an international collaboration and clinical trials from Europe and Japan, found overall response rates of 20% to 26%, a median duration of response between 5 to 9 months, and a median duration of survival ranging from 7 to 12.3 months. Gemcitabine also has been shown to be more effective than best supportive care in non-small cell lung cancer. In a phase I trial of irinotecan (50, 75, 100, and 115 mg/m2) in combination with 1,000 mg/m2 gemcitabine, three patients had documented partial responses: one with pancreas cancer at irinotecan 100 mg/m2, one with pancreas cancer, and one with metastatic carcinoma of unknown primary at irinotecan 115 mg/m2. Three of five non-small cell lung cancer patients had stable disease for four or more cycles at irinotecan doses of 50, 75, and 100 mg/m2; no non-small cell lung cancer patients were treated at irinotecan 115 mg/m2. We recommend that a combination of gemcitabine 1,000 mg/m2 and irinotecan 100 mg/m2 given on days 1 and 8 every 3 weeks be used as the starting dose in future phase II studies. Furthermore, based on the absence of severe nonhematologic toxicity or grade IV hematologic toxicity in the majority of patients treated at the highest dose, escalation of irinotecan to 115 mg/m2 may be considered for subsequent cycles in patients who do not experience > or =grade I hematologic or non-hematologic toxicity during the first cycle of gemcitabine/irinotecan combination chemotherapy.

Antimetabolites, Antineoplastic↗
PubMed1998

Dissecting the regulatory circuitry of a eukaryotic genome.

Genome-wide expression analysis was used to identify genes whose expression depends on the functions of key components of the transcription initiation machinery in yeast. Components of the RNA polymerase II holoenzyme, the general transcription factor TFIID, and the SAGA chromatin modification complex were found to have roles in expression of distinct sets of genes. The results reveal an unanticipated level of regulation which is superimposed on that due to gene-specific transcription factors, a novel mechanism for coordinate regulation of specific sets of genes when cells encounter limiting nutrients, and evidence that the ultimate targets of signal transduction pathways can be identified within the initiation apparatus.

Acetyltransferases↗
PubMed1998

Controlling gene expression in living cells through small molecule-RNA interactions.

Short RNA aptamers that specifically bind to a wide variety of ligands in vitro can be isolated from randomized pools of RNA. Here it is shown that small molecule aptamers also bound their ligand in vivo, enabling development of a method for controlling gene expression in living cells. Insertion of a small molecule aptamer into the 5' untranslated region of a messenger RNA allowed its translation to be repressible by ligand addition in vitro as well as in mammalian cells. The ability of small molecules to control expression of specific genes could facilitate studies in many areas of biology and medicine.

Animals↗
PubMed1998

The HIV-1 Tat cellular coactivator Tat-SF1 is a general transcription elongation factor.

The human immunodeficiency virus type 1 (HIV-1) Tat protein strongly and specifically stimulates transcription elongation from the HIV-1 LTR and provides an important in vitro model system to study this process. Here we use protein-affinity chromatography to identify cellular factors involved in transcription elongation. A Tat-affinity column bound one transcription factor, Tat-SF1, efficiently and selectively. Tat-SF1 was identified originally as a Tat-specific coactivator, but we show it is a general transcription elongation factor. Our results also reveal the existence of an ATP-inactivatable general elongation factor (AIEF) required for Tat-SF1 activity and for which Tat can substitute functionally.

Electrophoresis, Polyacrylamide Gel↗
PubMed1998

Dose and dose intensity as determinants of outcome in the adjuvant treatment of breast cancer. The Cancer and Leukemia Group B.

BACKGROUND: Both total dose and dose intensity of adjuvant chemotherapy are postulated to be important variables in the outcome for patients with operable breast cancer. The Cancer and Leukemia Group B study 8541 examined the effects of adjuvant treatment using conventional-range dose and dose intensity in female patients with stage II (axillary lymph node-positive) breast cancer. METHODS: Within 6 weeks of surgery (radical mastectomy, modified radical mastectomy, or lumpectomy), 1550 patients with unilateral breast cancer were randomly assigned to one of three treatment arms: high-, moderate-, or low-dose intensity. The patients received cyclophosphamide, doxorubicin, and 5-fluorouracil on day 1 of each chemotherapy cycle, with 5-fluorouracil administration repeated on day 8. The high-dose arm had twice the dose intensity and twice the drug dose as the low-dose arm. The moderate-dose arm had two thirds the dose intensity as the high-dose arm but the same total drug dose. Disease-free survival and overall survival were primary end points of the study. RESULTS: At a median follow-up of 9 years, disease-free survival and overall survival for patients on the moderate- and high-dose arms are superior to the corresponding survival measures for patients on the low-dose arm (two-sided P<.0001 and two-sided P = .004, respectively), with no difference in disease-free or overall survival between the moderate- and the high-dose arms. At 5 years, overall survival (average +/- standard error) is 79% +/- 2% for patients on the high-dose arm, 77% +/- 2% for the patients on the moderate-dose arm, and 72% +/- 2% for patients on the low-dose arm; disease-free survival is 66% +/- 2%, 61% +/- 2%, and 56% +/- 2%, respectively. CONCLUSION: Within the conventional dose range for this chemotherapy regimen, a higher dose is associated with better disease-free survival and overall survival.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1998

Dihydro-5-azacytidine and cisplatin in the treatment of malignant mesothelioma: a phase II study by the Cancer and Leukemia Group B.

BACKGROUND: In a prior Cancer and Leukemia Group B (CALGB) Phase II trial of patients with advanced, previously untreated mesothelioma, dihydro-5-azacytidine (DHAC) demonstrated a 17% response rate, including 1 complete response, with only mild myelosuppression. This Phase II study (CALGB 9031) was conducted to determine the effectiveness of and toxicities that would result from adding cisplatin to DHAC administered to the same patient population. METHODS: Thirty-six patients were treated with concurrent DHAC at 1500 mg/m2/day for 5 days by continuous infusion and cisplatin 15 mg/m2 daily for 5 days. Therapy was repeated every 3 weeks. Cisplatin was to be increased to 20 mg/m2 daily in subsequent cycles if toxicity was minimal. Therapy was continued until disease progression or excessive toxicity mandated discontinuation. RESULTS: Overall, 5 objective responses were observed in 29 evaluated patients (objective response rate, 17%). The median duration of response was 6.6 months. Median survival was 6.4 months, with a median time to clinical failure of 2.7 months. The major toxicity noted was significant chest/pericardial pain, as was observed with DHAC alone. There were 2 early deaths of unknown cause on Days 9 and 17 of therapy, respectively. Significant leukopenia was observed in 29% of patients, but there were no neutropenic fevers. CONCLUSIONS: The addition of cisplatin to DHAC did not increase the response rate over that observed with DHAC alone in patients with mesothelioma; however, it did increase toxicity, especially leukopenia. This combination is not recommended for further studies involving mesothelioma patients.

Adult↗
PubMed1998

Co-ordinated over-expression of the MRP and gamma-glutamylcysteine synthetase genes, but not MDR1, correlates with doxorubicin resistance in human malignant mesothelioma cell lines.

While human malignant mesothelioma is extremely resistant to chemotherapy, its intrinsic resistance mechanisms remain largely unknown. In this study, we used normal human mesothelial cells and 5 human mesothelioma cell lines not previously exposed to chemotherapeutic agents to demonstrate that the mRNA for the multidrug resistance-associated protein (MRP) and gamma-glutamylcysteine synthetase (gamma-GCSh) heavy subunit genes, but not the P-glycoprotein (MDR1) gene, are co-ordinately over-expressed in mesothelioma cell lines. Expression of MRP as detected with an anti-MRP antibody correlated with decreased doxorubicin accumulation and resistance of mesothelioma cells to this drug. Our results strongly suggest roles for MRP and gamma-GCSh in chemoresistance in mesotheliomas.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1998

Analysis of selective gene activation in yeast by differential display.

TATA box binding protein-associated factors (TAF(II)s) are dispensable for transcription of most genes in yeast. To further investigate the in vivo functions of TAF(II)s, differential display was used to identify a small subset of yeast genes whose transcription is dependent on yeast TAF(II)145, the core TAF(II) component that contacts TATA box-binding protein (TBP). Messenger RNA profiles derived from a wild-type TAF(II)145 strain and a temperature-sensitive taf(II)1145 strain were analyzed. Those genes whose messenger RNA level was greatly reduced in the temperature-sensitive taf(II)145 strain were cloned and further characterized. The procedure for performing differential display described here is modified from protocols provided by the manufacturer (Display Systems) and optimized for the yeast system.

Binding Sites↗
PubMed1998

Analysis of neuroendocrine markers, HER2 and CEA before and after chemotherapy in patients with stage IIIA non-small cell lung cancer: a Cancer and Leukemia Group B study.

Several studies have suggested that biochemical or molecular markers examined in non-small cell lung cancer carry prognostic or treatment response information. Non-small cell lung cancer patients whose tumors have neuroendocrine (NE) features may be more responsive to chemotherapy. In addition, increased expression of HER2 (c-erbB-2), a membrane-bound receptor with tyrosine kinase activity, has been associated with shortened survival. The Cancer and Leukemia Group B (CALGB) performed a study of patients with stage IIIA (N2 nodes positive) non-small cell lung cancer in which patients received initial chemotherapy followed by surgery, then post-operative therapy consisting of sequential chemotherapy and radiation therapy. Since all patients underwent mediastinoscopy, this provided an opportunity to compare pre- and post-chemotherapy tumor specimens to test the hypothesis that these proteins would predict treatment response. In particular, we hypothesized that the post-chemotherapy specimens would be enriched for NE marker negative cells because of the increased sensitivity of NE positive cells to chemotherapy. We performed immunohistochemical analysis for a panel of NE markers [neuron-specific enolase (NSE), Leu-7, chromogranin A (ChrA), synaptophysin (Syn)], HER2 and CEA to determine if there was an effect of therapy on the percentage of cells expressing these markers. Secondary endpoints were a correlation with chemotherapy response and survival. Slides were scored for intensity (0-4) and percentage of cells positive (0-4). Of 61 eligible patients, there were 38 with both pre- and post-chemotherapy specimens. When both intensity of staining and percentage of positive cells were considered, post-chemotherapy specimens had a higher percentage of positive NE markers compared with pre-chemotherapy. In addition, there was no correlation between NE marker, HER2 or CEA expression (prior to or post treatment) and response to chemotherapy or survival. These data do not support the hypothesis that NE positive tumor cells are preferentially killed by chemotherapy in patients with stage IIIA non-small cell lung cancer.

Biomarkers, Tumor↗
PubMed1998

Broad, but not universal, transcriptional requirement for yTAFII17, a histone H3-like TAFII present in TFIID and SAGA.

The RNA polymerase II general transcription factor TFIID is a multisubunit complex comprising TATA box-binding protein (TBP) and associated factors (TAFIIs). Experiments in yeast have shown that although most TAFIIs are required for viability, many genes are transcribed normally upon inactivation of individual and even multiple yTAFIIs. Here we analyze yTAFII17, recently found to be present in both the SAGA HAT complex as well as TFIID. Functional inactivation of yTAFII17 by temperature-sensitive mutation or depletion results in loss of transcription of many, but not all, genes. The upstream activating sequence (UAS), which contains the activator binding sites, is the region that renders a gene yTAFII17 dependent. In conjunction with previous studies, our results reveal that different TAFIIs have remarkably distinct properties.

Acetyltransferases↗
PubMed1998

Psychologic and neuropsychologic functioning of patients with limited small-cell lung cancer treated with chemotherapy and radiation therapy with or without warfarin: a study by the Cancer and Leukemia Group B.

PURPOSE: The current study assessed the psychologic and neuropsychologic functioning of patients with small-cell lung cancer who were randomized in a large clinical trial to receive intensive doxorubicin, cyclophosphamide, etoposide (ACE)/cisplatin, cyclophosphamide, etoposide (PCE) chemotherapy and radiation therapy (RT) to the primary tumor and prophylactic whole-brain irradiation with (regimen I) or without (regimen II) warfarin. PATIENTS AND METHODS: Patients' emotional states and cognitive functioning were assessed using the Profile of Mood States (POMS) and Trail Making B Test (Trails B), respectively. Two hundred ninety-five patients completed the POMS and Trails B at pretreatment, 224 patients after the completion of the ACE course of chemotherapy (week 9), and 177 patients after the completion of the PCE chemotherapy and RT (week 17). RESULTS: No differences on the POMS or Trails B measures were found between the two treatment arms as predicted, given that the only difference between the two treatment arms was the presence or absence of warfarin. Analysis of the POMS revealed that, overall, mean scores remained stable over the course of treatment; however, women showed a trend toward higher mean scores, which indicated a higher level of distress, compared with men at the pretreatment assessment. Examination of cognitive functioning, measured by the Trails B, revealed improved performance from baseline to post-ACE chemotherapy, which is consistent with a practice effect, but a significant worsening of Trails B scores post-RT compared with the pre-RT assessments, which is consistent with impaired cognitive functioning because of treatment (P < .0001). CONCLUSION: Emotional state, measured by the POMS, did not differ between the groups or change significantly over time in this study of small-cell lung cancer patients treated with a combination of chemotherapy and RT plus or minus warfarin. However, the pattern of relatively stable POMS scores and poorer Trails B performance post-RT suggested that this combination of chemotherapy and RT had a negative impact on cognitive functioning.

Adult↗
PubMed1998

Thoracic radiation therapy added to chemotherapy for small-cell lung cancer: an update of Cancer and Leukemia Group B Study 8083.

PURPOSE: To provide a 10-year update of the experience of the Cancer and Leukemia Group B (CALGB) in the addition of thoracic radiation therapy to chemotherapy in limited-stage small-cell lung cancer. PATIENTS AND METHODS: Three hundred ninety-nine patients with limited-stage small-cell lung cancer were randomized to receive thoracic radiation therapy that started on day 1 (arm I) or day 64 of chemotherapy treatment (arm II), or chemotherapy alone with cyclophosphamide, vincristine, and etoposide (later, doxorubicin). Thoracic radiation therapy consisted of 4,000 rad to the tumor and mediastinum with a 1,000-rad boost. All patients received prophylactic cranial radiation to a dose of 3,000 rad. RESULTS: Arm I patients had a median survival of 13.04 months, arm II patients 14.54 months, and arm III patients 13.58 months (log-rank test, P = .0072). Median time to clinical failure was 11 months in arm I, 11.21 months in arm II, and 8.7 months in arm III (log-rank test, P = .0004). CONCLUSION: With 10 years of follow-up, the two arms that included thoracic radiation therapy remain superior to chemotherapy alone. The addition of thoracic radiation therapy to combination chemotherapy improved both complete response rates and survival, with increased but acceptable toxicity.

Antineoplastic Combined Chemotherapy Protocols↗