A randomized phase 2 study of MK-2206 versus everolimus in refractory renal cell carcinoma

Background

Activation of the phosphoinisitide-3 kinase (PI3K) pathway through mutation and constitutive upregulation has been described in renal cell carcinoma (RCC), making it an attractive target for therapeutic intervention. We performed a randomized phase II study in vascular endothelial growth factor (VEGF) therapy refractory patients to determine whether MK-2206, an allosteric inhibitor of AKT, was more efficacious than the mammalian target of rapamycin inhibitor everolimus.

Patients and methods

A total of 43 patients were randomized in a 2:1 distribution, with 29 patients assigned to the MK-2206 arm and 14 to the everolimus arm. Progression-free survival (PFS) was the primary endpoint.

Results

The trial was closed at the first futility analysis with an observed PFS of 3.68 months in the MK-2206 arm and 5.98 months in the everolimus arm. Dichotomous response rate profiles were seen in the MK-2206 arm with one complete response and three partial responses in the MK-2206 arm versus none in the everolimus arm. On the other hand, progressive disease was best response in 44.8% of MK2206 versus 14.3% of everolimus-treated patients. MK-2206 induced significantly more rash and pruritis than everolimus, and dose reduction occurred in 37.9% of MK-2206 versus 21.4% of everolimus-treated patients. Genomic analysis revealed that 57.1% of the patients in the PD group had either deleterious TP53 mutations or ATM mutations or deletions. In contrast, none of the patients in the non-PD group had TP53 or ATM defects. No predictive marker for response was observed in this small dataset.

Conclusions

Dichotomous outcomes are observed when VEGF therapy refractory patients are treated with MK-2206, and MK-2206 does not demonstrate superiority to everolimus. Additionally, mutations in DNA repair genes are associated with early disease progression, indicating that dysregulation of DNA repair is associated with a more aggressive tumor phenotype in RCC.

Selumetinib with and without erlotinib in KRAS mutant and KRAS wild-type advanced nonsmall-cell lung cancer

BACKGROUND

KRAS mutations in NSCLC are associated with a lack of response to epidermal growth factor receptor inhibitors. Selumetinib (AZD6244; ARRY-142886) is an oral selective MEK kinase inhibitor of the Ras/Raf/MEK/ERK pathway.

PATIENTS AND METHODS

Advanced nonsmall-cell lung cancer (NSCLC) patients failing one to two prior regimens underwent KRAS profiling. KRAS wild-type patients were randomized to erlotinib (150 mg daily) or a combination of selumetinib (150 mg daily) with erlotinib (100 mg daily). KRAS mutant patients were randomized to selumetinib (75 mg b.i.d.) or the combination. The primary end points were progression-free survival (PFS) for the KRAS wild-type cohort and objective response rate (ORR) for the KRAS mutant cohort. Biomarker studies of ERK phosphorylation and immune subsets were carried out.

RESULTS

From March 2010 to May 2013, 89 patients were screened; 41 KRAS mutant and 38 KRAS wild-type patients were enrolled. Median PFS in the KRAS wild-type arm was 2.4 months [95% confidence interval (CI) 1.3-3.7] for erlotinib alone and 2.1 months (95% CI 1.8-5.1) for the combination. The ORR in the KRAS mutant group was 0% (95% CI 0.0% to 33.6%) for selumetinib alone and 10% (95% CI 2.1% to 26.3%) for the combination. Combination therapy resulted in increased toxicities, requiring dose reductions (56%) and discontinuation (8%). Programmed cell death-1 expression on regulatory T cells (Tregs), Tim-3 on CD8+ T cells and Th17 levels were associated with PFS and overall survival in patients receiving selumetinib.

CONCLUSIONS

This study failed to show improvement in ORR or PFS with combination therapy of selumetinib and erlotinib over monotherapy in KRAS mutant and KRAS wild-type advanced NSCLC. The association of immune subsets and immune checkpoint receptor expression with selumetinib may warrant further studies.

Phase I study of the halichondrin B analogue eribulin mesylate in combination with cisplatin in advanced solid tumors

BACKGROUND

Eribulin mesylate is a synthetic macrocyclic ketone analogue of Halichondrin B that has demonstrated high antitumor activity in preclinical and clinical settings. This phase I study aimed to determine the maximum tolerated dose (MTD), dose-limiting toxicities (DLTs), and pharmacokinetics in combination with cisplatin (CP) in patients with advanced solid tumours.

METHODS

Thirty-six patients with advanced solid tumours received eribulin mesylate 0.7-1.4 mg m(-2) and CP 60-75 mg m(-2). Eribulin mesylate was administered on days 1, 8, and 15 in combination with CP day 1 every 28-day cycle. The protocol was amended after dose level 4 (eribulin mesylate 1.4 mg m(-2), CP 60 mg m(-2)) when it was not feasible to administer eribulin mesylate on day 15 because of neutropenia; the treatment schedule was changed to eribulin mesylate on days 1 and 8 and CP on day 1 every 21 days.

RESULTS

On the 28-day schedule, three patients had DLT during the first cycle: grade (G) 4 febrile neutropenia (1.0 mg m(-2), 60 mg m(-2)); G 3 anorexia/fatigue/hypokalemia (1.2 mg m(-2), 60 mg m(-2)); and G 3 stomatitis/nausea/vomiting/fatigue (1.4 mg m(-2), 60 mg m(-2)). On the 21-day schedule, three patients had DLT during the first cycle: G 3 hypokalemia/hyponatremia (1.4 mg m(-2), 60 mg m(-2)); G 4 mucositis (1.4 mg m(-2), 60 mg m(-2)); and G 3 hypokalemia (1.2 mg m(-2), 75 mg m(-2)). The MTD and recommended phase II dose was determined as eribulin mesylate 1.2 mg m(-2) (days 1, 8) and CP 75 mg m(-2) (day 1), on a 21-day cycle. Two patients had unconfirmed partial responses (PR) (pancreatic and breast cancers) and two had PR (oesophageal and bladder cancers).

CONCLUSIONS

On the 21-day cycle, eribulin mesylate 1.2 mg m(-2), administered on days 1 and 8, in combination with CP 75 mg m(-2), administered on day 1 is well tolerated and showed preliminary anticancer activity.

A phase I trial of vertical inhibition of IGF signalling using cixutumumab, an anti-IGF-1R antibody, and selumetinib, an MEK 1/2 inhibitor, in advanced solid tumours

BACKGROUND

We completed a phase I clinical trial to test the safety and toxicity of combined treatment with cixutumumab (anti-IGF-1R antibody) and selumetinib (MEK 1/2 inhibitor).

METHODS

Patients with advanced solid tumours, refractory to standard therapy received selumetinib hydrogen sulphate capsules orally twice daily, and cixutumumab intravenously on days 1 and 15 of each 28-day cycle. The study used a 3+3 design, with a dose-finding cohort followed by an expansion cohort at the maximally tolerated dose that included pharmacokinetic and pharmacodynamic correlative studies.

RESULTS

Thirty patients were enrolled, with 16 in the dose-finding cohort and 14 in the expansion cohort. Grade 3 or greater toxicities included nausea and vomiting, anaemia, CVA, hypertension, hyperglycaemia, and ophthalmic symptoms. The maximally tolerated combination dose was 50 mg twice daily of selumetinib and 12 mg kg(-1) every 2 weeks of cixutumumab. Two patients achieved a partial response (one unconfirmed), including a patient with BRAF wild-type thyroid carcinoma, and a patient with squamous cell carcinoma of the tongue, and six patients achieved time to progression of >6 months, including patients with thyroid carcinoma, colorectal carcinoma, and basal cell carcinoma. Comparison of pre- and on-treatment biopsies showed significant suppression of pERK and pS6 activity with treatment.

CONCLUSIONS

Our study of anti-IGF-1R antibody cixutumumab and MEK 1/2 inhibitor selumetinib showed that the combination is safe and well-tolerated at these doses, with preliminary evidence of clinical benefit and pharmacodynamic evidence of target inhibition.

Skeletal muscle anabolism is a side effect of therapy with the MEK inhibitor: selumetinib in patients with cholangiocarcinoma

Background:

Cancer cachexia is characterised by skeletal muscle wasting; however, potential for muscle anabolism in patients with advanced cancer is unproven.

Methods:

Quantitative analysis of computed tomography images for loss/gain of muscle in cholangiocarcinoma patients receiving selumetinib (AZD6244; ARRY-142886) in a Phase II study, compared with a separate standard therapy group. Selumetinib is an inhibitor of mitogen-activated protein/extracellular signal–regulated kinase and of interleukin-6 secretion, a putative mediator of muscle wasting.

Results:

Overall, 84.2% of patients gained muscle after initiating selumetinib; mean overall gain of total lumbar muscle cross-sectional area was 13.6 cm²/100 days (∼2.3 kg on a whole-body basis). Cholangiocarcinoma patients who began standard treatment were markedly catabolic, with overall muscle loss of −7.3 cm²/100 days (∼1.2 kg) and by contrast only 16.7% of these patients gained muscle.

Conclusion:

Our findings suggest that selumetinib promotes muscle gain in patients with cholangiocarcinoma. Specific mechanisms and relevance for cachexia therapy remain to be investigated.

A rhesus macaque model of Streptococcus pneumoniae carriage

BACKGROUND

Nasopharyngeal colonization by Streptococcus pneumoniae precedes pneumococcal disease. Elucidation of procedures to prevent or eradicate nasopharyngeal carriage in a model akin to the human would help to diminish the incidence of both pneumonia and invasive pneumococcal disease.

METHODS

We conducted a survey of the nasopharynx of infant rhesus macaques from our breeding colony, in search of natural carriers of S. pneumoniae. We also attempted experimental induction of colonization, by nasopharyngeal instillation of a human S. pneumoniae strain (19F).

RESULTS

None of 158 colony animals surveyed carried S. pneumoniae in the nasopharynx. Colonization was induced in eight of eight infant rhesus by nasopharyngeal instillation and lasted 2weeks in 100% of the animals and 7weeks in more than 60%.

CONCLUSION

Rhesus macaques are probably not natural carriers of S. pneumoniae. The high rate and duration of colonization obtained in our experiments indicates that the rhesus macaque will serve as a human-like carriage model.

Phase I study of temsirolimus (CCI-779), carboplatin, and paclitaxel in patients (pts) with advanced solid tumors: NCIC CTG IND 179

3558

Background: Temsirolimus (T) has encouraging activity in many malignancies, including endometrial cancer and a combination with carboplatin and paclitaxel would logical regimen for further development. This trial was designed to assess the safety and tolerability of this combination and expand experience at the recommended dose in pts with endometrial and ovarian cancers. Methods: A 3+3 dose escalation Phase I study has been conducted in pts with advanced solid malignancies suitable for carboplatin and paclitaxel chemotherapy who had not received more than 2 prior lines of chemotherapy. To date, 31 eligible pts with a median age of 59 have been treated and 27 are evaluable for toxicity. Pts were entered in 6 dose levels, with the first two levels administering T on Days 8 and 15 and the next 4 levels switching to a D1, 8 administration. Eighteen had received prior chemotherapy and 15 prior radiation. Results: Day 8, 15 administration of T was not feasible due to myelosuppression on day 15. The combination of carboplatin and paclitaxel on day 1 with T on D1 and 8 has been well tolerated, and patients have received a median of 5 cycles of therapy. At dose level 6 (T 25 mg D1 and 8, paclitaxel 175 mg/m2 D1, carboplatin AUC 6 D1) dose limiting toxicity (DLT) was seen in one of 6 pts treated to date (Gr 4 thrombocytopenia) and a second pt had a possible DLT ( Gr 3 fatigue in presence of baseline fatigue). This dose level is being expanded in 4 endometrial and ovarian cancer pts. The regimen is active: of the 26 patients with follow-up data, there have been 10 with partial response (38.5%; med. duration 7.1 mo [1.0–12.7]) and 12 with stable disease (46%; med. duration 6.9 mo [1.3- 7.8]). One patient had progressive disease and three were inevaluable. Conclusions: The results indicate this combination is well tolerated and requires additional assessment in a Phase II setting. The recommended Phase II dose will be dose level 6 provided no further DLTs are observed in the additional 4 patients entered.

[Table: see text]

No significant financial relationships to disclose.

Phase II trial of gemcitabine/carboplatin (GC) followed by paclitaxel (P) in patients with performance status = 2,3 or other significant co-morbidity (HIV infection or s/p organ transplantation) in advanced non-small cell lung cancer (NSCLC)

7661

Introduction: The role of chemotherapy (Rx) in patients (pts) with advanced NSCLC and poor performance status (PPS) defined as PS = 2 or 3 is unclear. While survival appears to be enhanced, serious toxicity may occur. In addition, no treatment options have been defined for the growing population of pts with HIV infection or post organ transplantation. Based on a prior study (Cancer 2001;92:146–152), we evaluated the efficacy of sequential, dose attenuated GC followed by P in patients with PS=2,3, HIV infection or s/p solid organ transplantation. Patients and Methods: Rx naive patients with PPS and adequate organ function received G: 1,000 mg/m2 d 1,8 C: AUC=5 d 1 q 21d × 2 followed by P 80 mg/m2 q wk × 6 followed by a 2 wk break and then repeated until progression. Results: 47 of a projected 47 pts have been enrolled. Stage IIIb/IV: 8/39, PS 2/3= 26/19, HIV infection=2, solid organ transplantation=2. 12 (25%) had brain metastases. Thirty-nine pts completed two cycles of GC and 29 pts received at least one cycle of P. Overall response rate:19% (95% CI 1.2%-31.7%). Median survival: 5.8 mo. One year survival: 8.4%. Median event free survival: 3.3 months. Toxicity rates for GC: Grade (gr) 3 neutropenia, anemia and thrombocytopenia = 29.8%, 14.9%, 23.4% respectively, gr 4 neutropenia=19% and 10.6% had gr 4 thrombocytopenia. There were 2 gr 1 bleeding episodes, two pts received platelets and 8 pts received red cells. 8.5% had gr 3 fatigue and 10.6% had gr 3 febrile neutropenia, 4.3% had grade 3 nausea, vomiting. Gr 4 nonhematologic toxicities: Thromboembolism = 1 pt (2.1%), Fever = 1 (2.1%). Toxicity rates for P phase: 2.1% had gr 3 neutropenia and anemia. 4.3% had gr 3 neuropathy. There was 1 episode of gr 4 hemoptysis. Two patients received red cells. Conclusions: 1) Sequential GC to P is well tolerated and active in this population. 2) Survival is comparable to that of other regimens utilized in PS = 2 pts with superior tolerability. 3) The prognosis for these pts is very poor even with Rx.4. This is the first trial to prospectively evaluate Rx for pts with HIV disease or organ transplantation and NSCLC. Supported by Bristol Myers Squibb.

No significant financial relationships to disclose.

Cetuximab, paclitaxel, carboplatin and radiation for esophageal and gastric cancer

4029

Background: Cetuximab is an IgG1, chimerized, monoclonal antibody that binds specifically to the epidermal growth factor receptor. Cetuximab improves survival when combined with radiation for patients with locally advanced head and neck cancer. We evaluated the safety and efficacy of the addition of cetuximab to concurrent chemoradiation for patients with esophageal and gastric cancer. Methods: Patients with adenocarcinoma or squamous cell cancer of the esophagus or stomach without distant organ metastases were eligible. Patients with locally advanced disease from mediastinal, celiac, portal and gastric lymphadenopathy were eligible. Surgical resection was not required. Clinical complete response was defined as no tumor on postreatment endoscopic biopsy. Patients received cetuximab, 400mg/m2 week #1 then 250 mg/m2/week for 5 weeks, paclitaxel, 50 mg/m2/week, and carboplatin, AUC =2 weekly for 6 weeks, with concurrent 50.4 Gy radiation. Results: Thirty-seven patients have been entered. The median age was 61 (range of 30–87). Thirty-four have esophageal cancer and 3 have gastric cancer. Of the patients with esophageal cancer, twenty-five have adenocarcinoma and nine have squamous cell cancer. Thus far, 30 patients have completed treatment and are evaluable for toxicity. There have been no grade 4 non-hematologic toxicities and 1 pt had grade 4 neutropenia (3%). Six patients (20%) had grade 3 esophagitis. Other grade 3 toxicities included dehydration (n=5), rash (n=9), and paclitaxel/cetuximab hypersensitivity reactions (n=2). Eighteen of 27 patients (67%) have had clinical complete response. Seven pts out of 16 (43%) who have gone to surgery have had a pathologic CR. Conclusions: Cetuximab can be safely administered with chemoradiation for patients with esophageal cancer. Consistent with the data in head and neck cancer, cetuximab increases cutaneous toxicity but does not increase mucositis/esophagitis when combined with chemoradiation. Further evaluation is ongoing.

[Table: see text]

Accurate lymph node assessment prior to trimodality therapy for esophageal carcinoma

PURPOSE

The diagnosis of esophageal carcinoma has historically been associated with a poor prognosis. Recently, investigators have reported improved outcomes for this patient population with the use of trimodality therapy. These results have fueled the debate regarding which patients may benefit from this aggressive treatment course. This retrospective analysis was conducted in order to evaluate the importance of regional lymph node involvement, determined by surgical staging before the initiation of therapy.

PATIENTS AND MATERIALS

Between July 1991 and June 1999, 45 patients underwent surgical staging with thoracoscopy and/or laparoscopy followed by induction chemoradiation and surgical resection. All patients underwent consultation in our thoracic multidisciplinary clinic. Thoracoscopy included nodal sampling from American Thoracic Society levels 5, 6, 8, and 9 within the mediastinum. Laparoscopy included inspection of the liver and nodal sampling from the lesser curvature and the celiac axis. Preoperative chemoradiation consisted of two cycles of 5-fluorouracil (1000 mg/M2) and cisplatin (100 mg/M2) weeks 1 and 4 with 50.4 Gy. Radiotherapy was delivered at 1.8 Gy/fraction with 39.6 Gy being delivered to the large-field and 10.8 Gy to a small-field boost. The routine surgical procedure was an Ivor-Lewis esophagectomy performed 4 to 6 weeks after completion of induction therapy.

RESULTS

The median follow up was 24 months for all patients. The median overall survival was 23 months, with 1-, 2-, and 3-year survivals of 64%, 42%, and 34%, respectively. Thirty patients had pathological evidence of lymph node disease before therapy. The pathological complete response rate for the entire group was 51%. Node-positive patients had a path complete response rate of 14%, as compared with 59% for those who were NO. The median survival for these two groups was 15 months versus 35 months. Patients whose nodes were cleared by chemoradiation had a 3-year survival of 40%, whereas all patients with persistent nodal disease were dead by 2 years. Twenty-one patients have experienced recurrence of their disease. Thirteen patients had evidence of distant metastasis only, three local only, and five with both.

CONCLUSION

Trimodality therapy offers patients with esophageal cancer an opportunity for long-term survival. Our experience has shown that minimally invasive pretreatment surgical staging provides useful information that can predict complete response and can help in the selection of appropriate patients for aggressive therapy.

Promoter characterization and genomic organization of the human breast cancer resistance protein (ATP-binding cassette transporter G2) gene

The breast cancer resistance protein (BCRP) gene, formally known as ATP-binding cassette transporter G2 (ABCG2) gene, encodes an ABC half transporter that causes resistance to certain cancer chemotherapeutic drugs when transfected and expressed in drug sensitive cancer cells. Here we report the organization of the BCRP gene, and the initial characterization of the BCRP promoter. We identified the genomic sequence of BCRP and its promoter by screening a human genomic lambda phage library, as well as a BAC library, and by searching the human genome database. The BCRP gene spans over 66 kb and consists of 16 exons and 15 introns. The exons range in size from 60 to 532 bp. The translational start site is found in the second exon. The first exon contains the majority of the 5' UTR. Promoter activity was characterized by a luciferase reporter assay using transient transfection of the human breast cancer cell line MCF7, and the human choriocarcinoma cell lines JAR, BeWo and JEG-3, which we find to have high endogenous expression of BCRP. The BCRP gene is transcribed by a TATA-less promoter with several putative Sp1 sites, which are downstream from a putative CpG island. The sequence 312 bp directly upstream from the BCRP transcriptional start site conferred basal promoter activity. The 5' region upstream of the basal promoter is characterized by both positive and negative regulatory domains.

Phase I study of docetaxel and topotecan in patients with solid tumors

PURPOSE

Both docetaxel (DOC), a promoter and stabilizer of microtubule assembly, and topotecan (TOPO), a topoisomerase I inhibitor, have shown antitumor activity in a variety of solid tumor malignancies. This phase I trial was conducted to determine the overall and dose-limiting toxicities (DLT), the maximum tolerated dose (MTD) and the pharmacokinetics of the combination of DOC and TOPO in patients with advanced solid tumor malignancies.

METHODS

DOC was administered first at 60 mg/m2 without G-CSF and at 60, 70, and 80 mg/m2 with G-CSF by 1-h infusion on day 1 of the odd-numbered cycles (1, 3, 5, etc.) and on day 4 of the even-numbered cycles (2, 4, 6, etc.). TOPO 0.75 mg/m2 was administered as a 30-min infusion on days 1, 2, 3 and 4 of each cycle. G-CSF 300 micrograms was administered subcutaneously (s.c.) on days 5-14. Cycles were repeated every 21 days. All patients were premedicated with dexamethasone 8 mg orally every 12 h for a total of six doses starting on the day before DOC infusion.

RESULTS

A total of 22 patients were treated. Six patients were treated in cohort I with DOC and TOPO doses of 60 and 0.75 mg/m2, respectively, without G-CSF, and two patients developed DLT (febrile neutropenia). Four patients were treated in cohort II with DOC and TOPO doses of 60 and 0.75 mg/m2, respectively, with G-CSF, and no DLT was observed. Four patients were treated in cohort III with DOC and TOPO doses of 80 and 0.75 mg/m2, respectively, with G-CSF, and three developed DLT (febrile neutropenia). DOC was then de-escalated to 70 mg/m2 and delivered with TOPO 0.75 mg/m2 and G-CSF (cohort IV). Eight patients were treated at this dose level, and one DLT (febrile neutropenia) was observed. Two patients developed a severe hypersensitivity reaction shortly after the DOC infusion was started, one in cycle 1 and one in cycle 2. Both patients were removed from the study. Two patients developed severe dyspnea in the presence of progressive pulmonary metastases. Other nonhematological toxicities were mild. One patient with extensively pretreated ovarian carcinoma had a partial response, and eight patients with various solid tumor malignancies had stable disease with a median time to progression of 12 weeks (range 9-18 weeks). Administration of TOPO on days 1-4 and DOC on day 4 resulted in increased neutropenia.

CONCLUSIONS

DOC 80 mg/m2 given first as a 1-h infusion on day 1 with TOPO 0.75 mg/m2 given as a 0.5-h infusion on days 1, 2, 3 and 4 with G-CSF was considered the MTD. The recommended phase II dose for DOC given on day 1 is 70 mg/m2 with TOPO 0.75 mg/m2 given on days 1, 2, 3 and 4 every 21 days with G-CSF 300 micrograms s.c. on days 5-14. The alternative schedule with DOC given on day 4 and TOPO on days 1-4 is not recommended.

Breast cancer resistance protein directly confers SN-38 resistance of lung cancer cells

Breast cancer resistance protein (BCRP), an ABC half-transporter, is overexpressed in cancer cell lines selected with doxorubicin/verapamil, topotecan, or mitoxantrone. BCRP-overexpressing cells show cross-resistance to camptothecin derivatives such as irinotecan, SN-38 (the active metabolite of irinotecan), and topotecan. To test whether BCRP confers SN-38 resistance, we selected two SN-38 resistant sublines from PC-6 human small-cell lung cancer cells by SN-38, and then characterized these cells. Compared to PC-6 cells, the resistant sublines PC-6/SN2-5 and PC-6/SN2-5H were approximately 18- and 34-fold resistant, respectively. The intracellular SN-38 accumulation was reduced in the sublines, and BCRP mRNA was overexpressed in proportion to the degree of SN-38 resistance. These findings suggest that BCRP confers SN-38 resistance in the sublines. To confirm this hypothesis, PC-6/SN2-5 cells were transfected with antisense oligonucleotides complementary to portions of BCRP mRNA. The antisense oligonucleotides significantly suppressed BCRP mRNA expression, and enhanced SN-38 sensitivity in the subline. These data indicate that BCRP is directly involved with SN-38 resistance, by efflux transport of SN-38.

The use of concurrent chemotherapy with high-dose radiation before surgical resection in patients presenting with apical sulcus tumors

PURPOSE

Patients presenting with apical sulcus tumors have historically been treated with preoperative radiotherapy followed by surgical resection. Since 1991, we have delivered an induction regimen consisting of combination chemotherapy and high-dose radiation in an attempt to improve tumor responses and increase survival for this patient population.

PATIENTS AND MATERIALS

This retrospective analysis consisted of 23 (13 men and 10 women) consecutive patients who completed trimodality therapy. The median age was 53 years. Histologies included adenocarcinoma (nine patients), squamous cell (five patients), large cell (three patients), and undifferentiated non-small cell lung carcinoma (six patients). Pretreatment stages were T3NO (14 patients), T3N2 (two patients), T3N3 (one patient), T4NO (five patients), and T4N2 (one patient). Preoperative therapy consisted of daily radiotherapy (median dose, 59.4 Gy) delivered at 1.8 Gy/day and concurrent combination chemotherapy consisting of either two cycles of cisplatin and etoposide or weekly carboplatin and paclitaxel. Surgical resection typically included lobectomy with chest wall resection.

RESULTS

All 23 patients were available for analysis of response and survival. The median follow-up was 53 months. The median number of days between completion of induction therapy and surgery was 56 days. Postoperative complications included prolonged atelectasis (two patients), pulmonary embolism (one patient), subarachnoid-pleural fistula (one patient), and deep vein thrombosis in the subclavian vein (one patient). The pathological complete response rate to induction therapy was 46% for the entire group. An additional 38% had evidence of tumor regression at the time of surgery. The 5-year disease-free and overall survivals were 36% and 49%, respectively. The median overall survival was 33 months. The median overall survival for those who achieved a pathological complete response has not been reached. Analysis of factors including age, sex, histology, differentiation, stage of disease, and radiation dose failed to identify any predictors of response or survival. CONCLUSION Concurrent chemotherapy and high-dose radiation can be safely delivered before surgery in patients presentingwith apical sulcus tumors. Our results compare favorably to other institutional series and support the further investigation of this approach in prospective trials.

Pharmacokinetic and pharmacodynamic study of the combination of docetaxel and topotecan in patients with solid tumors

PURPOSE

The sequence in which chemotherapeutic agents are administered can alter their pharmacokinetics, therapeutic effect, and toxicity. We evaluated the pharmacokinetics and pharmacodynamics of docetaxel and topotecan when coadministered on two different sequences of administration.

PATIENTS AND METHODS

On cycle 1, docetaxel was administered as a 1-hour infusion at 60 mg/m(2) without filgrastim and at 60, 70, and 80 mg/m(2) with filgrastim on day 1, and topotecan was administered at 0.75 mg/m(2) as a 0.5-hour infusion on days 1 to 4. On cycle 2, topotecan was administered on days 1 to 4, and docetaxel was administered on day 4. Cycles were repeated every 21 days. Blood samples for high-performance liquid chromatography measurement of docetaxel (CL(DOC)) and topotecan (CL(TPT)) total clearance were obtained on day 1 of cycle 1 and day 4 of cycle 2. CL(DOC) and CL(TPT) were calculated using compartmental methods.

RESULTS

Mean +/- SD CL(DOC) in cycles 1 and 2 were 75.9 +/- 79.6 L/h/m(2) and 29.2 +/- 17.3 L/h/m(2), respectively (P: <.046). Mean +/- SD CL(TPT) in cycles 1 and 2 were 8.5 +/- 4.4 L/h/m(2) and 9.3 +/- 3.4 L/h/m(2), respectively (P: >. 05). Mean +/- SD neutrophil nadir in cycles 1 and 2 were 4,857 +/- 6, 738/microL and 2,808 +/- 4,518/microL, respectively (P: =.02).

CONCLUSION

Administration of topotecan on days 1 to 4 and docetaxel on day 4 resulted in an approximately 50% decrease in docetaxel clearance and was associated with increased neutropenia.

Expression of breast cancer resistance protein in blast cells from patients with acute leukemia

Breast cancer resistance protein (BCRP) is a novel member of the adenosine triphosphate-binding cassette superfamily of transport proteins. Transfection and enforced expression of BCRP in drug-sensitive cells confer resistance to mitoxantrone, doxorubicin, daunorubicin, and topotecan. We studied blast cells from 21 acute leukemia patients (20 acute myeloid leukemia, 1 acute lymphocytic leukemia) for the expression of BCRP mRNA using a quantitative reverse-transcription polymerase chain reaction assay. BCRP mRNA expression varied more than 1000-fold among the samples tested, with low or barely detectable expression in half of the samples. Seven samples (33%) had relatively high expression of BCRP mRNA. High expression of BCRP did not correlate strongly with high expression of P-glycoprotein, suggesting that BCRP may cause resistance to certain antileukemic drugs in P-glycoprotein-negative cases. High expression of BCRP mRNA is sufficiently frequent in AML to warrant more extensive investigations to determine the relation of disease subtype and treatment outcome to BCRP expression and function.

Methotrexate cross-resistance in a mitoxantrone-selected multidrug-resistant MCF7 breast cancer cell line is attributable to enhanced energy-dependent drug efflux

Cellular resistance to the antifolate methotrexate (MTX) is often caused by target amplification, uptake defects, or alterations in polyglutamylation. Here we have examined MTX cross-resistance in a human breast carcinoma cell line (MCF7/MX) selected in the presence of mitoxantrone, an anticancer agent associated with the multidrug resistance (MDR) phenotype. Examination of protein expression and enzyme activities showed that MCF7/MX cells displayed none of the classical mechanisms of MTX resistance. They did, however, exhibit an ATP-sensitive accumulation defect accompanied by reduced polyglutamylation. Although the kinetics of drug uptake was similar between parental and resistant cells, the resistant cells exhibited increased energy-dependent drug efflux. This suggested the involvement of an ATP-binding cassette (ABC) transporter. However, cells transfected with the breast cancer resistance protein (BCRP)-the ABC transporter known to be highly overexpressed in MCF7/MX cells and to confer mitoxantrone resistance (D. D. Ross et al., J. Natl. Cancer Inst. 91: 429-433, 1999)-were not MTX resistant, which suggested that this transporter is not involved in MTX cross-resistance. Moreover, members of the MRP protein family of transport proteins, which had previously been implicated in MTX resistance, were not found to be overexpressed in the MCF7/MX cells. Thus, our data suggest that a novel MTX-specific efflux pump may be involved in this unusual cross-resistance phenotype.

Fumitremorgin C reverses multidrug resistance in cells transfected with the breast cancer resistance protein

Fumitremorgin C (FTC) is a potent and specific chemosensitizing agent in cell lines selected for resistance to mitoxantrone that do not overexpress P-glycoprotein or multidrug resistance protein. The gene encoding a novel transporter, the breast cancer resistance protein (BCRP), was recently found to be overexpressed in a mitoxantrone-selected human colon cell line, S1-M1-3.2, which was used to identify FTC. Because the drug-selected cell line may contain multiple alterations contributing to the multidrug resistance phenotype, we examined the effect of FTC on MCF-7 cells transfected with the BCRP gene. We report that FTC almost completely reverses resistance mediated by BCRP in vitro and is a pharmacological probe for the expression and molecular action of this transporter.

Safe pulmonary resection after chemotherapy and high-dose thoracic radiation

BACKGROUND

Pulmonary resection after high-dose thoracic irradiation is reported to be associated with a high morbidity and mortality, and has been considered to be prohibitive.

METHODS

We report safe pulmonary resection in 19 consecutive patients receiving neoadjuvant therapy that included greater than 59 Gy thoracic radiation. The mean thoracic radiation dose was 61.8 Gy (range 59.5-66.5) and mean age was 52 years (range 36-72 years). Cell type was adenocarcinoma (6), squamous (7), and other non-small cell lung cancer (NSCLC) (6). Sixteen of 19 patients received concurrent chemotherapy. Median time from end of treatment to surgical resection was 89 days (range 22-258 days). Surgical resection included 13 lobectomies and six pneumonectomies (four right, two left).

RESULTS

A complete pathologic response was seen in 8 of 19 (42%) patients. Three patients required intraoperative transfusion of blood. Mean intensive care unit stay was 2.0 days (range 1-8 days), and mean length of stay (LOS) was 8.0 days (range 3-18 days). There were four postoperative complications; one bronchopulmonary fistula, one subarachnoid-pleural fistula, and 2 patients with prolonged atelectasis. There was no incidence of acute respiratory distress syndrome (ARDS) or operative mortality.

CONCLUSIONS

Pulmonary resection, including pneumonectomy, after chemotherapy and high-dose thoracic radiation may be performed safely with a low rate of intraoperative and postoperative complications.

Atypical multidrug resistance: breast cancer resistance protein messenger RNA expression in mitoxantrone-selected cell lines

BACKGROUND

Human cancer cell lines grown in the presence of the cytotoxic agent mitoxantrone frequently develop resistance associated with a reduction in intracellular drug accumulation without increased expression of the known drug resistance transporters P-glycoprotein and multidrug resistance protein (also known as multidrug resistance-associated protein). Breast cancer resistance protein (BCRP) is a recently described adenosine triphosphate-binding cassette transporter associated with resistance to mitoxantrone and anthracyclines. This study was undertaken to test the prevalence of BCRP overexpression in cell lines selected for growth in the presence of mitoxantrone.

METHODS

Total cellular RNA or poly A+ RNA and genomic DNA were isolated from parental and drug-selected cell lines. Expression of BCRP messenger RNA (mRNA) and amplification of the BCRP gene were analyzed by northern and Southern blot hybridization, respectively.

RESULTS

A variety of drug-resistant human cancer cell lines derived by selection with mitoxantrone markedly overexpressed BCRP mRNA; these cell lines included sublines of human breast carcinoma (MCF-7), colon carcinoma (S1 and HT29), gastric carcinoma (EPG85-257), fibrosarcoma (EPF86-079), and myeloma (8226) origins. Analysis of genomic DNA from BCRP-overexpressing MCF-7/MX cells demonstrated that the BCRP gene was also amplified in these cells.

CONCLUSIONS

Overexpression of BCRP mRNA is frequently observed in multidrug-resistant cell lines selected with mitoxantrone, suggesting that BCRP is likely to be a major cellular defense mechanism elicited in response to exposure to this drug. It is likely that BCRP is the putative "mitoxantrone transporter" hypothesized to be present in these cell lines.

A multidrug resistance transporter from human MCF-7 breast cancer cells

MCF-7/AdrVp is a multidrug-resistant human breast cancer subline that displays an ATP-dependent reduction in the intracellular accumulation of anthracycline anticancer drugs in the absence of overexpression of known multidrug resistance transporters such as P glycoprotein or the multidrug resistance protein. RNA fingerprinting led to the identification of a 2.4-kb mRNA that is overexpressed in MCF-7/AdrVp cells relative to parental MCF-7 cells. The mRNA encodes a 655-aa [corrected] member of the ATP-binding cassette superfamily of transporters that we term breast cancer resistance protein (BCRP). Enforced expression of the full-length BCRP cDNA in MCF-7 breast cancer cells confers resistance to mitoxantrone, doxorubicin, and daunorubicin, reduces daunorubicin accumulation and retention, and causes an ATP-dependent enhancement of the efflux of rhodamine 123 in the cloned transfected cells. BCRP is a xenobiotic transporter that appears to play a major role in the multidrug resistance phenotype of MCF-7/AdrVp human breast cancer cells.

The 95-kilodalton membrane glycoprotein overexpressed in novel multidrug-resistant breast cancer cells is NCA, the nonspecific cross-reacting antigen of carcinoembryonic antigen

Human breast carcinoma MCF-7/AdrVp cells display a novel multidrug resistance phenotype that is characterized by the overexpression of a 95-kDa membrane glycoprotein (p95) and by marked reduction in intracellular anthracycline accumulation, without overexpression of P-glycoprotein or the multidrug resistance protein MRP. p95 is also highly expressed in multidrug-resistant NCI-H1688 cells derived from a human small cell lung carcinoma. Deglycoslyated p95 from NCI-H1688 cells was isolated by two-dimensional gel electrophoresis and then digested with trypsin. The tryptic peptides were analyzed by mass spectrometry and microsequencing. These analyses identified p95 to be identical to NCA-90, the nonspecific cross-reacting antigen related to the carcinoembryonic antigen (CEA). Further confirmation that p95 is indeed NCA-90 was obtained by Northern and Western blot studies using probes or antibodies specific for p95, NCA-90, or CEA family members. Western blot studies also revealed that CEA itself is overexpressed in MCF-7/AdrVp cells compared to parental MCF-7/W cells. The enforced expression of NCA-90 protein in HeLa cells stably transfected with NCA-90 cDNA did not result in increased resistance of the transfected cells to daunorubicin or a decrease in daunorubicin accumulation in the transfected cells compared to cells transfected only with the expression vector. However, a recent report by H. Kawaharata et al. (Int. J. Cancer, 72: 377-382, 1997) of diminished accumulation, retention, and cytotoxicity of doxorubicin in EJNIH3T3 cells in which enforced expression of CEA was accomplished leaves open the possibility that the overexpression of CEA, possibly in combination with that of NCA-90, could account at least in part for the drug resistant phenotype displayed by MCF-7/AdrVp cells.

Annamycin circumvents resistance mediated by the multidrug resistance-associated protein (MRP) in breast MCF-7 and small-cell lung UMCC-1 cancer cell lines selected for resistance to etoposide

Annamycin (Ann) is a highly lipophilic anthracycline antibiotic that has been shown to circumvent MDR-1 both in vitro and in vivo. A liposomal formulation of Ann is currently in phase I clinical trials. The multidrug resistance-associated protein (MRP) has been found to be over-expressed in some human leukemias at relapse and to be a poor prognostic factor in neuroblastoma. We studied the in vitro cytotoxicity and the cellular uptake and efflux of Ann and doxorubicin (Dox) in 2 pairs of human cell lines, breast carcinoma MCF7 and small-cell lung cancer UMCC-1, and their MRP-expressing counterparts, MCF-7/VP and UMCC-1/VP. Resistance indexes were 1.1 and 1.4 for Ann vs. 6.9 and 11.6 for Dox. Ann cellular accumulation was 3- to 5-fold higher than that of Dox in both sensitive and resistant cells. No changes in drug efflux between sensitive and resistant cells were observed in the case of Ann, while Dox efflux at 1 hr was 20-25% higher in resistant than in sensitive cells. By confocal microscopy, the subcellular distribution of Ann was identical in sensitive and resistant cells, localizing mostly in the perinuclear structures, while that of Dox was exclusively nuclear in sensitive cells and nuclear and in the cell membrane in resistant cells. There was a good correlation between the extent of DNA breaks induced by each drug in the different cell lines and cytotoxic effect. Our results indicate that Ann may be effective in the treatment of malignancies in which MRP is a relevant mechanism of clinical resistance.

A novel quinoline derivative, MS-209, overcomes drug resistance of human lung cancer cells expressing the multidrug resistance-associated protein (MRP) gene

PURPOSE AND METHODS

MS-209 is a newly synthesized quinoline compound used orally to overcome human P-glycoprotein (Pgp)-mediated multidrug resistance (MDR). The multidrug resistance-associated protein (MRP) gene is thought to play an important role in MDR in lung cancer. To investigate whether MS-209 could also overcome MRP-mediated MDR, we examined the effect of the compound using a cytotoxicity assay on MDR1 gene-negative drug-selected MDR and wildtype lung cancer cells with various levels of MRP gene expression. The effects of MS-209 were compared with those of verapamil (VER) and cyclosporin A (CsA). The level of MRP gene expression in the cells was evaluated semiquantitatively by RT-PCR. For vincristine (VCR), intracellular accumulation of [3H]-VCR was measured with or without MS-209.

RESULTS

In MDR UMCC-1/VP small-cell lung carcinoma cell line, 5 microM of MS-209 and VER enhanced the cytotoxicity of etoposide, doxorubicin (DOX) and VCR more than twofold, and completely reversed the resistance to VCR. The mean reversing effects of MS-209 on DOX and VCR were significantly stronger than those of VER and CsA. In wildtype non-small-cell lung carcinoma cells, the effects of MS-209 were almost equal to those of VER and CsA. The effect of these three agents correlated with the level of MRP gene expression. The MS-209-induced increase in intracellular accumulation of VCR was proportional to the level of MRP gene expression in these cells.

CONCLUSION

Our results indicate that MS-209 is a potentially useful drug that can overcome MRP-mediated intrinsic and acquired MDR in human lung cancer.

H19 gene overexpression in atypical multidrug-resistant cells associated with expression of a 95-kilodalton membrane glycoprotein

The multidrug resistance phenotype of human breast carcinoma MCF-7/AdrVp cells is characterized by overexpression of a 95-kilodalton membrane glycoprotein (p95), accompanied by a marked reduction in intracellular anthracycline accumulation, without overexpression of P-glycoprotein or the multidrug resistance protein. We discovered that the mRNA of the H19 gene is overexpressed in MCF-7/AdrVp cells relative to parental MCF-7 cells or drug-sensitive MCF-7/AdrVp revertant cells. H19 is an imprinted gene with an important role in fetal differentiation, as well as a postulated function as a tumor suppressor gene. Another p95-overexpressing multidrug-resistant cell line, human lung carcinoma NCI-H1688, also displays high levels of H19 mRNA. In contrast, several multidrug-resistant cell lines that overexpress P-glycoprotein or the multidrug resistance protein do not have higher levels of H19 mRNA than their drug-sensitive counterparts. This is the first report of H19 gene overexpression accompanying any form of drug resistance. The association of H19 and p95 gene expression in drug resistance warrants further study.

Expression of multidrug resistance-associated protein (MRP) mRNA in blast cells from acute myeloid leukemia (AML) patients

A specific and quantitative reverse-transcription polymerase chain reaction (RT-PCR) assay was developed for measuring the mRNA of the multidrug resistance-associated protein (MRP). A region corresponding to bp 3897-4471 of MRP cDNA is amplified, which encompasses approximately half of the second nucleotide-binding domain (NBD2). In two multidrug resistant (MDR) sublines of the HL-60 human acute myeloid leukemia (AML) cell line which overexpress MRP but not P-glycoprotein, the assay detects elevated levels of MRP mRNA (4- to 8-fold) relative to the drug-sensitive parental cells (designated HL-60/W). Blast cells from 24 patients with AML were also studied for MRP expression using this RT-PCR method. Expression of MRP was normalized for that of beta-actin in the blast cells, which was also determined by RT-PCR. All of these blast cell samples had MRP expression that was detectable after 35 PCR cycles. Eighteen of these patients samples had levels of expression of MRP mRNA equal to or less than that expressed by HL-60/W cells. In six patient blast cell specimens, the expression of MRP mRNA was up to 1.7-fold higher than that of HL-60/W cells. In 21 specimens, the steady-state intracellular accumulation of daunorubicin (1 microgram/ml, 3h) was also determined. The blast cells with MRP mRNA expression higher than HL-60/W had a lower median accumulation of daunorubicin compared to those whose MRP expression was less than HL-60/W, suggesting a functional defect in drug transport in the cells with higher MRP expression; a similar trend toward lower daunorubicin accumulation was also noted in the one-third of samples that displayed the highest expression of MDR1 mRNA (also determined by RT-PCR). These studies illustrate the range of expression of MRP in AML blast cell specimens. The identification of MRP overexpression in MDR AML cell lines and in some AML patient blast cells with low intracellular daunorubicin accumulation warrants further study of MRP as a component of clinical drug resistance in AML.

Susceptibility of idarubicin, daunorubicin, and their C-13 alcohol metabolites to transport-mediated multidrug resistance

The intracellular pharmacokinetics and cytotoxicity of idarubicin (IDA), daunorubicin (DNR), and their corresponding C-13 alcohol metabolites, idarubicinol (IDAol) and daunorubicinol (DNRol), were studied in drug-sensitive HL-60/W human leukemia cells, and in two multidrug-resistant (MDR) sublines, HL-60/Vinc (overexpress P-glycoprotein, Pgp) and HL-60/Adr (overexpress multidrug resistance-associated protein, MRP). Intracellular drug accumulation (1 micrograms/mL) and retention were measured by flow cytometry. Mean intracellular steady-state concentration (Css, fluorescence units/cell) and area under the intracellular drug concentration x time curve (AUC, Fl.U/cell.min) were calculated. Relative to the values for the respective drugs in HL-60/W cells, the Css and AUC of IDA were much higher than those of DNR in the MDR cell lines, with Css and AUC of IDAol intermediate between IDA and DNR. In the MDR cell lines, the MDR modulator cyclosporine A (CsA), in concentrations of 0.3 to 30 mumol/L, caused minimal effects on 3-hr IDA accumulation, intermediate enhancement of IDAol accumulation, and greatest enhancement of DNR accumulation. The MDR cell lines were much less resistant to IDA (3- to 16-fold) than to DNR (65- to 117-fold). This difference was not the result of IDA being more potent than DNR, since the sensitivity of HL-60/W cells to IDA differed from their sensitivity to DNR by < 2-fold. The cellular pharmacokinetics and cytotoxicity of IDA in MDR human breast carcinoma cells MCF-7/AdrVp, which overexpress the putative MDR transporter P-95, were far superior to those of DNR, and were comparable to these parameters for IDA in parental MCF-7/W cells. These studies demonstrate that the cellular pharmacology and cytotoxicity of IDA in MDR cell lines that overexpress MRP, Pgp, or P-95 are more advantageous than those of DNR, suggesting that IDA is less susceptible to the transport-mediated MDR mechanism manifested. IDA is not completely invulnerable to MDR, however, since the MDR sublines studied did display a demonstrable level of resistance to IDA, compared with their drug-sensitive counterparts. IDAol, the major plasma metabolite of IDA, demonstrated behavior intermediate between the MDR-susceptible drug DNR and its parent compound, suggesting that its cytotoxic action is subject to transport-mediated cellular defenses.(ABSTRACT TRUNCATED AT 400 WORDS)

Characterization of a 95 kilodalton membrane glycoprotein associated with multi-drug resistance

Over-expression of a 95-kDa membrane protein (P-95) has been reported previously in the multi-drug-resistant (MDR) breast cancer cell line MCF-7/AdrVp and the MDR small cell lung cancer line NCI-H1688. We have now developed anti-sera against gel-purified }-95 protein from each of these cell lines. Western blotting with each serum demonstrates a broad band at 95-kDa with detergent-solubilized membrane proteins from MCF-7/AdrVp and NCI-H1688 cells, which is barely detectable in membrane proteins from drug-sensitive parental MCF-7 cells. Each anti-serum cross-reacts with a 190-kDa membrane protein (P-190) in NCI-H1688 but not MCF-7/AdrVp cells. Immunoblotting and silver staining of NCI-H1688 membrane proteins separated by two-dimensional gel electrophoresis demonstrates that P-95 and P-190 run as broad streaks with low iso-electric points. Incubation of NCI-H1688 cells with tunicamycin or cleavage of carbohydrate residues of NCI-H1688 or MCF-7/AdrVp membrane proteins with PNGase F leads to the appearance of a sharp 35-kDa band reactive with anti-P-95 antisera. This 35-kDa protein has been isolated by two-dimensional gel electrophoresis. Neuraminidase digestion converts P-95 to a broad 65-kDa immunoreactive band, indicating the presence of terminal sialic acid residues. In conclusion, P-95 is an N-linked sialoglycoprotein with a 35-kDa polypeptide core.

An etoposide-resistant lung cancer subline overexpresses the multidrug resistance-associated protein

We have characterised an etoposide-resistant subline of the small-cell lung cancer cell line, UMCC-1, derived at our centre. Subline UMCC-1/VP was developed by culturing the parent line in increasing concentrations of etoposide over 16 months. UMCC-1/VP is 20-fold resistant to etoposide by MTT assays, relative to the parent line, and is cross-resistant to doxorubicin, vincristine and actinomycin D, but not to taxol, cisplatin, melphalan, thiotepa or idarubicin. Topoisomerase II immunoblotting demonstrates a 50% reduction of the protein in the resistant subline. The UMCC-1/VP subline demonstrates a marked decrease in the accumulation of [3H]etoposide relative to the parent line, as well as a modest reduction in the accumulation of daunorubicin. Reverse transcription-polymerase chain reaction assays demonstrate no detectable mdr1 expression but marked expression of the multidrug resistance-associated protein (MRP) gene in the resistant subline. Northern blotting with an MRP cDNA probe confirms marked overexpression of the MRP gene only in the UMCC-1/VP subline. Western blotting with antisera against MRP peptide confirms a 195 kDa protein band in the UMCC-1/VP subline. Southern blotting experiments demonstrate a 10-fold amplification of the MRP gene in the resistant subline. Depletion of glutathione with buthionine sulphoximine sensitised UMCC-1/VP cells to daunorubicin and etoposide. Our studies indicate that MRP gene expression may be induced by etoposide and may lead to reduced accumulation of the drug.

Expression of a 95 kDa membrane protein is associated with low daunorubicin accumulation in leukaemic blast cells

A 95 kDa membrane protein (P-95) has been previously noted to be overexpressed in a doxorubicin-resistant subline of the MCF-7 breast cancer line and in clinical samples obtained from patients with solid tumours refractory to doxorubicin. We performed Western blotting on blast cell lysates from adults with acute myeloid leukaemia, using antisera to P-95. Concomitant flow cytometric assays measured daunorubicin accumulation and retention. Blasts from 16/46 patient samples had detectable P-95 and had reduced accumulation of daunorubicin compared with the negative marrows. Experiments with the P-95 positive MCF-7 multidrug-resistant subline demonstrated decreased daunorubicin accumulation and retention relative to the sensitive parent line. AML blast cells positive for P-95 also demonstrated greater overall in vitro survival in the presence of daunorubicin relative to the P-95-negative samples. The expression of P-95 did not correlate with failure to achieve an initial complete remission with daunorubicin and cytarabine induction chemotherapy. We conclude that the P-95 protein may possess an efflux transporter function, and may represent another mechanism responsible for anthracycline resistance in acute myeloid leukaemia.

Topoisomerase expression in cancer cell lines and clinical samples

Topoisomerase II activity has been previously associated with chemosensitivity to cytotoxic agents in cell lines made resistant to drugs in vitro. Examination of unselected cancer cell lines, however, shows a relatively poor correlation between topoisomerase II content and intrinsic chemoresistance. Studies of topoisomerase II expression in clinical materials from human tumor biopsies also demonstrate a poor relationship with the response of the cancers to induction chemotherapy. A major problem with assessing topoisomerase II activity in clinical materials is the marked heterogeneity of the enzyme among the cells and the associated high proportion of tumor cells which are not traversing the cell cycle. While the activation of oncogenes may disregulate topoisomerase II expression in some experimental systems, there is currently no evidence that enzyme activity is disconnected from cell cycling in clinical cancer specimens. Novel techniques of topoisomerase II measurement may permit more accurate correlation of enzyme activity with clinical chemosensitivity.

Etoposide: current status and future perspectives in the management of malignant neoplasms

Etoposide has demonstrated highly significant clinical activity against a wide variety of neoplasms, including germ-cell malignancies, small-cell lung cancer, non-Hodgkin's lymphomas, leukemias, Kaposi's sarcoma, neuroblastoma, and soft-tissue sarcomas. It is also one of the important agents in the preparatory regimens given prior to bone marrow and peripheral stem-cell rescue. Despite its high degree of efficacy in a number of malignancies, the optimal dose, schedule, and dosing form remain to be defined. It is possible that continuous or prolonged inhibition of the substrate, i. e., topoisomerase II, may be the key factor for the cytotoxic effects of etoposide. Clinical studies have shown the activity of etoposide to be schedule-dependent, with prolonged dosing, best accomplished by the oral dosing form, offering a therapeutic advantage. This benefit awaits validation by prospective randomized studies, some of which are in progress. Recent clinical investigations have focused on the use of etoposide in combination with (a) cytokines to ameliorate myelosuppression, the dose-limiting toxicity of etoposide; (b) agents such as cyclosporin A and verapamil to alter the p-glycoprotein (mdr1) function; and (c) topoisomerase I inhibitors to modulate the substrate upon which it acts. There is continued interest in the development of etoposide to its maximal clinical dimensions and in the examination of alternative biochemical and mechanistic approaches to further our understanding of this highly active agent.

Chromosome alterations in human small cell lung cancer: frequent involvement of 5q

Deletions of the 3p chromosome region and molecular alterations of the tumor suppressor genes RB1 and TP53, located, respectively, at 13q14 and 17p13, are well-documented in small cell lung cancer (SCLC). Because of technical difficulties, karyotypes of primary SCLC specimens are rarely reported. In this study, detailed cytogenetic analysis was performed on 13 early passage SCLC cell lines and fresh specimens, including 4 lung primaries. Numerous chromosome alterations were found, even in newly diagnosed primary tumors. Consistent with previous molecular studies, chromosomal losses of 3p (13 cases) and 17p13 (12 cases) were frequently observed. Numerical losses of chromosome 13 and structural rearrangements affecting 13q14 were identified in 10 specimens. In addition, losses of chromosome 5 and structural alterations of 5q occurred in 12 tumors; among these, 9 displayed losses of region 5q13-q21. Double minutes were found in 4 cases (3 of 5 specimens from patients who received prior cytotoxic therapy but only 1 of 8 from untreated patients). DNA analysis revealed amplification of either MYC1 or MYCN in cells from each of these 4 tumors. Overall, the cytogenetic findings underscore that progression of SCLC involves multiple genetic changes and suggest further that a tumor suppressor gene(s) on 5q may contribute to SCLC tumorigenesis.

Attenuating the hypertensive response to laryngoscopy and endotracheal intubation using awake fibreoptic intubation

Blood pressure and pulse rate measurements were recorded in 35 patients undergoing endotracheal intubation during general anaesthesia (Group A), and 35 patients who had an awake fibreoptic intubation under local anaesthesia (Group B). The mean arterial pressure in Group A rose by a mean of 35 mmHg immediately after intubation, compared with a mean fall of 9 mmHg in Group B. The mean pulse rate in Group A rose by 24 beats per minute (b.p.m.) immediately after intubation, compared with a rise of 3 b.p.m. in Group B. Both these differences were statistically significant (P less than 0.0001 and P less than 0.001 respectively, Mann Whitney U test). Postoperative discomfort was assessed 24 h later by means of linear analogue scales. There was a statistically higher mean score in relation to nose discomfort in Group B (P less than 0.002). Awake fibreoptic intubation successfully reduces the pressor response to endotracheal intubation in normotensive adults. It is suitable for use in those patients who are at risk from the pressor response.

Modulation of neuroendocrine surface antigens in oncogene-activated small cell lung cancer lines

Small cell lung cancer (SCLC) manifests a number of neuroendocrine differentiation features and antigenic characteristics that distinguish the tumour from non-small cell lung cancer (NSCLC). Several surface antigens on SCLC cells, identified by clusters of monoclonal antibodies (MAbs), distinguish SCLC and other neuroendocrine tumours of NSCLC. Stable transfection of the c-myc proto-oncogene has been reported to confer upon classic SCLC cells the growth properties and morphology of the variant subtype of SCLC (SCLC-v). Furthermore, insertion of the v-Ha-ras oncogene into such SCLC-v cells has been found to induce features typical of NSCLC. We have used classic SCLC cells transfected with c-myc, or co-transformed with c-myc and v-Ha-ras, to examine the expression of characteristics SCLC cluster antigens. Flow cytometric assays reveal that SCLC cells co-transformed with c-myc and v-Ha-ras oncogenes down-modulate SC-1, SC-2 and SC-5A surface antigens to levels approaching, in some cases, those seen with NSCLC cells. The SC-4 surface antigen is not modulated by activation of these oncogenes. These findings support clinical and laboratory observations that important transitions can occur between subtypes of human lung cancer cells, and that these shifts may play a role in the clinical progression of lung cancer.

An adherent subline of a unique small-cell lung cancer cell line downregulates antigens of the neural cell adhesion molecule

Small-cell lung cancer (SCLC) lines are distinguished from non-small-cell lung cancer (NSCLC) lines by their growth in floating aggregates, in contrast to the adherent monolayers formed by NSCLC cells in culture. Of 50 well-characterized SCLC lines recently described by the National Cancer Institute (NCI)-Navy Medical Oncology Branch, only four variant cell lines (SCLC-v) grew as adherent monolayers. One line, NCI-H446, was unique in growing long-term with coexisting floating and surface adherent subpopulations. We have physically segregated these two populations over many passages in vitro to enrich for relatively pure cultures of floating and adherent cells. No differences in c-myc expression, keratin pattern, or cytogenetic appearance were found between the adherent and floating sublines. However, expression of the neuroendocrine marker neuron-specific enolase in the floating cells was three times that found in the adherent cells. The floating subline also had much greater surface expression of neuroendocrine tumor antigens detected by monoclonal antibodies UJ13A and HNK-1, which have been recently shown to detect the neural cell adhesion molecule (NCAM) on SCLC cells. Two other adherent SCLC-v lines were also found to be unreactive with UJ13A and HNK-1, generalizing the association between NCAM expression and the growth of most SCLC cultures as floating aggregates. In conclusion, we have an interesting model to study expression of NCAM as related to the adhesive properties of SCLC cells.

Identification of conditioned medium proteins from human cancer cells adapted to serum-free conditions

Recent studies have shown that human cancer cell lines can be adapted to grow in serum-free, unsupplemented RPMI-1640 (RO) medium. We have developed similar techniques to rapidly identify proteins of interest in serum-free conditioned medium (CM) of human lung cancer cell lines. Classic and variant small cell lung cancer (SCLC) lines were adapted to growth in RO medium. CM from each line was concentrated and fractionated on an anion-exchange column of a fast protein liquid chromatography system. Concentrates of each fraction were loaded onto lanes of minigels of an automated electrophoresis system. Analysis of the chromatograms reveals peaks seen only in CM of the classic SCLC lines. Electrophoretic analysis of the fractions containing these peaks reveal protein bands distinguishing between the subtypes of human SCLC. One protein was purified to homogeneity with subsequent reversed-phase chromatography and identified by protein microsequencing as histone H2B. These automated techniques have general use in the rapid identification of CM proteins associated with the differentiation or progression of the many types of neoplastic cells which can be adapted to growth in RO medium.

Interaction of recombinant human tumor necrosis factor and etoposide in human lung cancer cell lines

Studies have suggested that recombinant tumor necrosis factor-alpha (TNF-alpha) may potentiate the killing of murine tumor cells by drugs targeted at DNA topoisomerase II. We have examined the combined cytotoxic effects of the topoisomerase-targeted drug etoposide and TNF in small cell lung cancer (SCLC) and non-small cell lung cancer (NSCLC) cell lines using clonogenic assays and a novel flow cytometry technique relying on differential uptake of fluorescein diacetate (FDA) and propidium iodide (PI) by viable and nonviable cells. Good correlation of IC50 determinations for etoposide were noted between clonogenic assays and the FDA/PI technique for both classic and variant SCLC cell lines. The effects of etoposide on the classic SCLC line H209 were potentiated by TNF with a decrease in the IC50 from 3.3 microM to 1.0 microM as determined by FDA/PI. Tumor necrosis factor alone had little effect on the growth or cloning efficiency of H209 cells. Tumor necrosis factor alone stimulated the growth and cloning of variant SCLC line N417, but the cytotoxicity of etoposide was not potentiated by TNF in N417 cells. Tumor necrosis factor alone inhibited the growth and cloning of the NSCLC line H125 but exerted a marked protective effect against higher concentrations of etoposide. It appears that the interaction of TNF with etoposide varies between cell lines and between subclasses of human lung cancer.

Differentiation of human variant small cell lung cancer cell lines to a classic morphology by retinoic acid

Variant small cell lung cancer (SCLC) is distinguished from the classic histology by changes in growth characteristics and morphology, c-myc amplification, a loss of some biochemical markers, and relative chemo- and radioresistance. Three variant SCLC lines were incubated in 1 microM all-trans retinoic acid. After 8-10 days, a marked change in morphology was noted in all three lines, with tight cell aggregation and central necrosis of large floating spheroids similar to classic SCLC. The retinoid-treated cells demonstrated decreases in growth rate and cloning efficiency to levels comparable with classic SCLC cell lines. Retinoic acid incubation caused a reproducible decrease in c-myc expression in variant SCLC cells, but was not noted to increase L-dopa decarboxylase, an enzyme which biochemically distinguishes classic from variant SCLC cell lines. Retinoid exposure led to an increase in HLA and Leu-7 antigens, but a reduction of antibody binding to 3-fucosyllactosamine, a dominant SCLC glycolipid antigen. Clonogenic assays revealed that the variant cells, after incubation in retinoic acid, became more sensitive to etoposide, but more resistant to Adriamycin. We conclude that exposure of variant SCLC cells to retinoic acid can lead to a morphologic phenotype similar to classic SCLC, but with substantial differences in cell biology. ?

Potentiation of interferon induction of class I major histocompatibility complex antigen expression by human tumor necrosis factor in small cell lung cancer cell lines

The response of class I major histocompatibility complex antigen expression to in vitro administration of interferon and tumor necrosis factor alpha (TNF-alpha) was measured using class I major histocompatibility complex-deficient small cell lung cancer cell lines. Significant induction also was observed using gamma interferon (IFN-gamma) alone, whereas TNF-alpha alone yielded only modest induction. Classic small cell lung cancer cell lines NCI-H146 and NCI-H209 best demonstrated synergistic HLA and beta 2-microglobulin antigen induction with IFN-gamma and TNF-alpha with the following dose schedule: 3-6 days of TNF-alpha (200 units/ml) followed by 48 h of IFN-gamma (100 IU/ml). Induction was quantitated using an 125I-Protein A radioimmunoassay. Synergistic induction of the HLA and beta 2-microglobulin surface antigens on NCI-H146 was also possible with alpha interferon and TNF-alpha but required a higher concentration of the interferon, i.e., 3-6 days of TNF-alpha (200 units/ml) followed by 48 h of alpha interferon (1000 units/ml). Small cell lung cancer cell line NCI-H146 was further studied for expression of major histocompatibility complex messenger RNA using the optimal doses and sequence of addition of IFN-gamma and TNF-alpha as indicated above. A significant induction with IFN-gamma alone and synergistic induction with both IFN-gamma and TNF-alpha was quantitated for both HLA-A2 and beta 2-microglobulin transcripts using Northern blot analysis. Incubation with relatively low subcytotoxic doses of IFN-gamma and TNF-alpha also resulted in a marked synergistic decrease in c-myc message.

Staging, prognostic factors, and special considerations in small cell lung cancer

New treatment approaches in the fight against SCLC are clearly on the horizon and some are already in clinical trials. With this in mind, several comments concerning future directions in staging this disease can be made: 1. Staging is important and complete staging is needed in order to continue to build meaningful information. 2. Limited/Extensive disease categories are in use and remain important; yet this system is not completely adequate. There are subsets within each group that do better: minimal disease versus bulky disease in limited stage, extraabdominal v intraabdominal in extensive disease, and single organ versus multiple organ involvement. Therefore, a new staging system is needed. The TNM system is designed primarily to define surgical resectability and will thus not adequately address the issues for SCLC unless the N and M categories are markedly enlarged. A staging symposium was recently held in Europe to begin to address potential approaches to staging and an American staging conference is planned. 3. Biomarkers: In the broad range of possible markers, most are not sufficiently sensitive or specific to supplant clinical exam and routine testing. But newer tests such as NSE, CK-BB and tumor surface antigen expression and recognition may impact on staging in the near future. 4. Finally, as the biology of SCLC is further understood, much of the derived understanding will likely change the staging and prognostic factors.

Markedly different antibody responses to immunized small cell and non-small cell lung cancer cells

Monoclonal antibodies (MoAbs) to antigens of human small cell lung cancer (SCLC) and non-small cell lung cancer (NSCLC) were produced from BALB/c mice immunized with either intact cultured cells or membrane preparations from cultured tumor cells. Of 172 MoAbs produced from two NSCLC immunized mice and reactive to NSCLC cells, 137 bound staphylococcal Protein A directly, and only 11 of these 172 MoAbs were significantly reactive with cultured SCLC cells by a solid-phase radioimmunoassay. In contrast, only 16 of 99 MoAbs produced from two SCLC immunized mice and reactive to SCLC cells directly bound Protein A, and most were of an IgM isotype, but 98 of 99 of these antibodies also reacted with cultured NSCLC target plates. Twenty hybridomas producing antibodies reactive with lung cancer cells but not with a B-lymphoblastoid line were cloned. Eleven of these cloned hybridomas were from NSCLC fusions, and nine were from SCLC fusions. When representative hybridoma supernatants were tested against a broad panel of SCLC and NSCLC target plates a similar pattern was seen, with the supernatants from NSCLC-derived hybridomas only reacting strongly to the NSCLC target plates, but the supernatants from SCLC-derived hybridomas always reacting to both SCLC and NSCLC plates. We conclude that the humoral response to immunization with NSCLC cells or membrane preparations is predominantly IgG and that to SCLC is predominantly IgM. Furthermore, many IgG MoAbs reactive with NSCLC lines are poorly reactive with SCLC cells.

Combination chemotherapy with doxorubicin and mitomycin C in non-small cell bronchogenic carcinoma. Severe pulmonary toxicity from q 3 weekly mitomycin C

Forty-five patients with advanced, measurable, or evaluable non-small bronchogenic carcinoma (NSCBC) were treated with doxorubicin and mitomycin C combination chemotherapy. The first 27 patients received doxorubicin 50 mg/m2 I.V. every 3 weeks and mitomycin C 10 mg/m2 I.V. every 3 weeks. Because of severe cardiopulmonary toxicity in seven patients, with four otherwise unexplained deaths, the next 18 patients were treated with the mitomycin C dose reduced to 10 mg/m2 every 6 weeks. Overall, 11 patients (25%) responded, with one complete and 10 partial remissions. Eight responses (30%) were observed in the patients who received mitomycin C every 3 weeks and three responses (17%) were found in those given mitomycin C every 6 weeks (p less than 0.5), with no cardiopulmonary toxicity in the latter group. The median survival was 21 weeks for the entire group of patients, with the group receiving mitomycin C every 3 weeks living a median of 15.5 weeks and those given mitomycin C every 6 weeks surviving 35.5 weeks (p less than 0.025). We conclude that there is a higher tumor response rate but more cardiopulmonary toxicity and shorter survival among the group receiving mitomycin C every 3 weeks compared to those receiving mitomycin C every 6 weeks. Future studies should consider this toxicity of mitomycin C administered on an every-3-week schedule.