Disparities in Characteristics, Access to Care, and Oncologic Outcomes in Young-Onset Colorectal Cancer at a Safety-Net Hospital.

PURPOSE: Young-onset colorectal cancer is an emerging cause of significant morbidity and mortality globally. Despite this, limited data exist regarding clinical characteristics and outcomes, particularly in safety-net populations where access to care is limited. We aimed to study disparities in clinical characteristics and outcomes in patients with young-onset colorectal cancer in the safety-net setting. METHODS: We performed a retrospective review of patients < 50 years old diagnosed and/or treated for colorectal cancer between 2001 and 2017 at a safety-net hospital. Kaplan-Meier and Cox regression models were constructed to compare overall survival (OS), progression-free survival (PFS), and relapse-free survival (RFS) by race and ethnicity, stratifying for relevant clinical and pathologic factors. RESULTS: A total of 395 young-onset patients diagnosed at a safety-net hospital were identified and 270 were included in the analysis (49.6% Hispanic, 25.9% non-Hispanic Black, 20.0% non-Hispanic White, and 4.4% other). Non-Hispanic White race was independently associated with worse OS (hazzard ratio [HR], 0.53; 95% CI, 0.29 to 0.97), as were lack of insurance, higher clinical stage, and mismatch repair proficiency. There was no significant difference seen in PFS or RFS between racial and ethnic groups. CONCLUSION: Non-Hispanic White race or ethnicity was found to be independently associated with worse OS in a safety-net population of patients with young-onset colorectal cancer. Other independent predictors of worse OS include higher stage, lack of insurance, and mismatch repair proficiency.

Racial/Ethnic Disparities and Survival Characteristics in Non-Pancreatic Gastrointestinal Tract Neuroendocrine Tumors.

Background: We studied the effect of race and ethnicity on disease characteristics and survival in gastrointestinal neuroendocrine tumors. Methods: The Surveillance, Epidemiology, and End Results database was used to select patients with non-pancreatic gastrointestinal neuroendocrine tumors diagnosed between 2004 and 2015. Trends in survival were evaluated among three groups: Hispanic, non-Hispanic White, and non-Hispanic Black. Kaplan-Meier and Cox regression methods were performed to calculate overall survival and cause-specific survival after adjusting for patient and tumor characteristics. Results: A total of 26,399 patients were included in the study: 65.1% were non-Hispanic White, 19.9% were non-Hispanic Black, and 15% were Hispanic. Non-Hispanic White patients were more likely to be male (50.0%, p < 0.001), older than 60 years (48.0%, p < 0.001), and present with metastatic disease (17.7%, p < 0.001). Non-Hispanic White patients had small intestine neuroendocrine tumors, while Hispanic and non-Hispanic Black patients had rectum neuroendocrine tumors as the most common primary site. Hispanic patients had better overall survival, while non-Hispanic Black patients had better cause-specific survival versus non-Hispanic White patients. This finding was confirmed on multivariable analysis where Hispanic patients had improved overall survival compared to non-Hispanic White patients (Hazard ratio (HR): 0.89 (0.81-0.97)), whereas non-Hispanic Black patients had better cause-specific survival compared to non-Hispanic White patients (HR: 0.89 (0.80-0.98)). Conclusions: Race/ethnicity is an independent prognostic factor in patients with gastrointestinal neuroendocrine tumors.

Cellular heterogeneity during mouse pancreatic ductal adenocarcinoma progression at single-cell resolution.

Pancreatic ductal adenocarcinoma (PDA) is a major cause of cancer-related death with limited therapeutic options available. This highlights the need for improved understanding of the biology of PDA progression, a highly complex and dynamic process featuring changes in cancer cells and stromal cells. A comprehensive characterization of PDA cancer cell and stromal cell heterogeneity during disease progression is lacking. In this study, we aimed to profile cell populations and understand their phenotypic changes during PDA progression. To that end, we employed single-cell RNA sequencing technology to agnostically profile cell heterogeneity during different stages of PDA progression in genetically engineered mouse models. Our data indicate that an epithelial-to-mesenchymal transition of cancer cells accompanies tumor progression in addition to distinct populations of macrophages with increasing inflammatory features. We also noted the existence of three distinct molecular subtypes of fibroblasts in the normal mouse pancreas, which ultimately gave rise to two distinct populations of fibroblasts in advanced PDA, supporting recent reports on intratumoral fibroblast heterogeneity. Our data also suggest that cancer cells and fibroblasts may be dynamically regulated by epigenetic mechanisms. This study systematically describes the landscape of cellular heterogeneity during the progression of PDA and has the potential to act as a resource in the development of therapeutic strategies against specific cell populations of the disease.

Blocking Monocytic Myeloid-Derived Suppressor Cell Function via Anti-DC-HIL/GPNMB Antibody Restores the In Vitro Integrity of T Cells from Cancer Patients.

PURPOSE: Blocking the function of myeloid-derived suppressor cells (MDSC) is an attractive approach for cancer immunotherapy. Having shown DC-HIL/GPNMB to be the T-cell-inhibitory receptor mediating the suppressor function of MDSCs, we evaluated the potential of anti-DC-HIL mAb as an MDSC-targeting cancer treatment. EXPERIMENTAL DESIGN: Patients with metastatic cancer (n = 198) were analyzed by flow cytometry for DC-HIL or PDL1 expression on blood CD14+HLA-DRno/lo MDSCs. Their suppressor function was assessed by in vitro coculture with autologous T cells, and the ability of anti-DC-HIL or anti-PDL1 mAb to reverse such function was determined. Tumor expression of these receptors was examined histologically, and the antitumor activity of the mAb was evaluated by attenuated growth of colon cancers in mice. RESULTS: Patients with metastatic cancer had high blood levels of DC-HIL+ MDSCs compared with healthy controls. Anti-DC-HIL mAb reversed the in vitro function in ∼80% of cancer patients tested, particularly for colon cancer. Despite very low expression on blood MDSCs, anti-PDL1 mAb was as effective as anti-DC-HIL mAb in reversing MDSC function, a paradoxical phenomenon we found to be due to upregulated expression of PDL1 by T-cell-derived IFNγ in cocultures. DC-HIL is not expressed by colorectal cancer cells but by CD14+ cells infiltrating the tumor. Finally, anti-DC-HIL mAb attenuated growth of preestablished colon tumors by reducing MDSCs and increasing IFNγ-secreting T cells in the tumor microenvironment, with similar outcomes to anti-PDL1 mAb. CONCLUSIONS: Blocking DC-HIL function is a potentially useful treatment for at least colorectal cancer with high blood levels of DC-HIL+ MDSCs.See related commentary by Colombo, p. 453.

Regorafenib for Patients with Metastatic Colorectal Cancer Who Progressed After Standard Therapy: Results of the Large, Single-Arm, Open-Label Phase IIIb CONSIGN Study.

BACKGROUND: In the phase III CORRECT trial, regorafenib significantly improved survival in treatment-refractory metastatic colorectal cancer (mCRC). The CONSIGN study was designed to further characterize regorafenib safety and allow patients access to regorafenib before market authorization. METHODS: This prospective, single-arm study enrolled patients in 25 countries at 186 sites. Patients with treatment-refractory mCRC and an Eastern Cooperative Oncology Group performance status (ECOG PS) ≤1 received regorafenib 160 mg once daily for the first 3 weeks of each 4-week cycle. The primary endpoint was safety. Progression-free survival (PFS) per investigator assessment was the only efficacy evaluation. RESULTS: In total, 2,872 patients were assigned to treatment and 2,864 were treated. Median age was 62 years, ECOG PS 0/1 was 47%/53%, and 74% had received at least three prior regimens for metastatic disease. Median treatment duration was three cycles. Treatment-emergent adverse events (TEAEs) led to dose reduction in 46% of patients. Regorafenib-related TEAEs led to treatment discontinuation in 9%. Grade 5 regorafenib-related TEAEs occurred in <1%. The most common grade ≥3 regorafenib-related TEAEs were hypertension (15%), hand-foot skin reaction (14%), fatigue (13%), diarrhea (5%), and hypophosphatemia (5%). Treatment-emergent grade 3-4 laboratory toxicities included alanine aminotransferase (6%), aspartate aminotransferase (7%), and bilirubin (13%). Ongoing monitoring identified one nonfatal case of regorafenib-related severe drug-induced liver injury per DILI Working Group criteria. Median PFS (95% confidence interval [CI]) was 2.7 months (2.6-2.7). CONCLUSION: In CONSIGN, the frequency and severity of TEAEs were consistent with the known safety profile of regorafenib. PFS was similar to reports of phase III trials. ClinicalTrials.gov: NCT01538680. IMPLICATIONS FOR PRACTICE: Patients with metastatic colorectal cancer (mCRC) who fail treatment with standard therapies, including chemotherapy and monoclonal antibodies targeting vascular endothelial growth factor or epidermal growth factor receptor, have few treatment options. The multikinase inhibitor regorafenib was shown to improve survival in patients with treatment-refractory mCRC in the phase III CORRECT (N = 760) and CONCUR (N = 204) trials. However, safety data on regorafenib for mCRC in a larger number of patients were not available. The CONSIGN trial, carried out prospectively in more than 2,800 patients across 25 countries, confirmed the safety profile of regorafenib from the phase III trials and reinforced the importance of using treatment modifications to manage adverse events.

A Phase I Clinical Trial of the Phosphatidylserine-targeting Antibody Bavituximab in Combination With Radiation Therapy and Capecitabine in the Preoperative Treatment of Rectal Adenocarcinoma.

OBJECTIVES: There is interest in improving the tumoricidal effects of preoperative radiotherapy for rectal carcinoma by studying new radiosensitizers. The safety and toxicity profile of these combination regimens needs rigorous clinical evaluation. The primary objective of this study was to evaluate the toxicity of combining bavituximab, an antibody that targets exposed phosphatidylserine, with capecitabine and radiation therapy. MATERIALS AND METHODS: Patients with stage II or III rectal adenocarcinoma were enrolled on a phase I study combining radiation therapy, capecitabine, and bavituximab. A standard 3+3 trial designed was used. RESULTS: In general, bavituximab was safe and well tolerated in combination with radiation therapy and capecitabine in the treatment of rectal adenocarcinoma. One patient at the highest dose level experienced a grade III infusion reaction related to the bavituximab. One tumor demonstrated a complete pathologic response to the combination treatment. CONCLUSIONS: Bavituximab is safe in combination with capecitabine and radiation therapy at the doses selected for the study. Further clinical investigation would be necessary to better define the efficacy of this combination.

A Phase II, Randomized, Double-Blind, Placebo-Controlled Study of Simtuzumab in Combination with FOLFIRI for the Second-Line Treatment of Metastatic KRAS Mutant Colorectal Adenocarcinoma.

LESSONS LEARNED: The safety profile in the patient groups who received FOLFIRI and simtuzumab did not differ from that in the FOLFIRI and placebo group.The addition of simtuzumab to chemotherapy with FOLFIRI does not improve clinical outcomes in patients with metastatic KRAS mutant colorectal carcinoma. BACKGROUND: Simtuzumab, a humanized IgG4 monoclonal antibody to lysyl oxidase-like 2 (LOXL2), blocks desmoplastic reaction in colorectal carcinoma (CRC) cells in vitro. METHODS: Patients with metastatic Kirsten rat sarcoma viral oncogene homolog (KRAS) mutant CRC were randomized to receive second-line 5-fluorouracil, leucovorin, and irinotecan (FOLFIRI) with either 200 or 700 mg simtuzumab or placebo every 2 weeks in cycles of 28 days. Progression-free survival (PFS), overall survival (OS), objective response rate (ORR), and safety were assessed. RESULTS: In total, 249 patients were randomized and treated with FOLFIRI/simtuzumab 700 mg (n = 84), FOLFIRI/simtuzumab 200 mg (n = 85), and FOLFIRI/placebo (n = 80). After a median follow-up of 5.1, 3.8, and 5.5 months, respectively, median PFS for each of the respective treatment groups was 5.5 months (adjusted HR [95% CI], p value versus placebo; 1.32 [0.92, 1.89]; p = .10), 5.4 months (1.45 [1.01, 2.06]; p = .04), and 5.8 months. Median OS was 11.4 months (1.23 [0.80, 1.91]; p = .25), 10.5 months (1.50 [0.98, 2.30]; p = .06), and 16.3 months, respectively. ORR was 11.9%, 5.9%, and 10%, respectively. Simtuzumab was tolerable in metastatic KRAS mutant CRC patients. CONCLUSION: The addition of simtuzumab to FOLFIRI did not improve clinical outcomes in patients with metastatic KRAS mutant CRC. The Oncologist 2017;22:243-e8.

Phase II Trial of Preoperative Radiation With Concurrent Capecitabine, Oxaliplatin, and Bevacizumab Followed by Surgery and Postoperative 5-Fluorouracil, Leucovorin, Oxaliplatin (FOLFOX), and Bevacizumab in Patients With Locally Advanced Rectal Cancer: 5-Year Clinical Outcomes ECOG-ACRIN Cancer Research Group E3204.

LESSONS LEARNED: The 5-year oncologic outcomes from the trial regimen were excellent. However, the neoadjuvant and surgical toxicity of this regimen was significant and was the primary reason for the low compliance with adjuvant systemic therapy.Due to the lack of an improvement in the pathologic complete response rate, the substantial associated toxicity, and the negative phase III trials of adjuvant bevacizumab in colon cancer, this regimen will not be pursued for further study. BACKGROUND: The addition of bevacizumab to chemotherapy improves overall survival for metastatic colorectal cancer. We initiated a phase II trial to evaluate preoperative capecitabine, oxaliplatin, and bevacizumab with radiation therapy (RT) followed by surgery and postoperative 5-fluorouracil, leucovorin, oxaliplatin (FOLFOX), and bevacizumab for locally advanced rectal cancer. The purpose of this report is to describe the 5-year oncologic outcomes of this regimen. METHODS: In a phase II Simon two-stage design study, we evaluated preoperative treatment with capecitabine (825 mg/m(2) b.i.d. Monday-Friday), oxaliplatin (50 mg/m(2) weekly), bevacizumab (5 mg/kg on days 1, 15, and 29), and RT (50.4 Gy). Surgery was performed by 8 weeks after RT. Beginning 8-12 weeks after surgery, patients received FOLFOX plus bevacizumab (5 mg/kg) every 2 weeks for 12 cycles (oxaliplatin stopped after 9 cycles). The primary endpoint was a pathologic complete response (path-CR) rate of 30%. Fifty-seven patients with resectable T3/T4 rectal adenocarcinoma were enrolled between 2006 and 2010. RESULTS: Of 57 enrolled patients, 53 were eligible and included in the analysis. Forty-eight (91%) patients completed preoperative therapy, all of whom underwent curative surgical resection. Nine patients (17%) achieved path-CR. There were 29 worst grade 3 events, 8 worst grade 4 events, and 2 patient deaths, 1 of which was attributed to study therapy. Twenty-six patients (54%) began adjuvant chemotherapy. After a median follow-up period of 41 months, the 5-year overall survival (OS) rate for all patients was 80%. Only 2 patients experienced cancer recurrence: 1 distant (liver) and 1 loco-regional (pelvic lymph nodes), respectively. Both of these patients are still alive. The 5-year relapse-free survival rate was 81%. CONCLUSION: Despite the path-CR primary endpoint of this trial not being reached, the 5-year OS and recurrence-free survival rates were excellent. However, the neoadjuvant and surgical toxicity of this regimen was significant and was the primary reason for the low compliance with adjuvant systemic therapy. Because of the lack of an improvement in the path-CR rate, the substantial associated toxicity, and the negative phase III trials of adjuvant bevacizumab in colon cancer, this regimen will not be pursued for further study.

Phase 2 study of preoperative radiation with concurrent capecitabine, oxaliplatin, and bevacizumab followed by surgery and postoperative 5-fluorouracil, leucovorin, oxaliplatin (FOLFOX), and bevacizumab in patients with locally advanced rectal cancer: ECOG 3204.

BACKGROUND: Recent studies have demonstrated the feasibility of combining oxaliplatin with 5-fluorouracil (5-FU) or capecitibine and radiation therapy. The addition of bevacizumab to chemotherapy improves overall survival for metastatic disease. We initiated a phase 2 trial to evaluate preoperative capecitabine, oxaliplatin, and bevacizumab with radiation therapy followed by surgery and postoperative 5-FU, leucovorin, oxaliplatin (FOLFOX) and bevacizumab for locally advanced rectal cancer. METHODS: Fifty-seven patients with resectable T3/T4 rectal adenocarcinoma were enrolled. Preoperative treatment was capecitabine (825 mg/m(2) twice daily from Monday to Friday), oxaliplatin (50 mg/m(2) weekly), bevacizumab (5 mg/kg on days 1, 15, 29), and radiation therapy (50.4 Gy). Surgery was performed by 6 weeks after neoadjuvant therapy. Beginning 8 to 12 weeks after surgery, patients received FOLFOX plus bevacizumab (5 mg/kg) every 2 weeks for 12 cycles. RESULTS: Fifty-four of 57 enrolled patients were eligible. Forty-nine (91%) patients completed preoperative therapy and underwent surgery. Nine patients (17%; 90% confidence interval, 9%-27%) achieved pathologic complete response. Thirty-two patients (59%) experienced pathologic tumor downstaging, and 53% and 15% of patients experienced worst grade 3 and grade 4 acute toxicity, respectively. Forty-seven percent of patients who underwent surgery experienced a surgical complication. CONCLUSIONS: The primary endpoint of a 30% pathologic complete response rate was not reached; however, the majority of patients experienced pathologic downstaging with this regimen. Increased wound-healing delays and complications may have been related to the addition of bevacizumab, oxaliplatin, or both. Continued observation of these patients will establish the long-term morbidity and efficacy of this combined modality approach.

Cells lacking IKKα show nuclear cyclin D1 overexpression and a neoplastic phenotype: role of IKKα as a tumor suppressor.

The catalytic subunits of IκB kinase (IKK) complex, IKKα and IKKß, are involved in activation of NF-κB and in mediating a variety of other biological functions. Though these proteins have a high-sequence homology, IKKα exhibits different functional characteristics as compared with IKKß. Earlier, we have shown that cyclin D1 is overexpressed and predominantly localized in the nucleus of IKKα(-/-) cells, indicating that IKKα regulates turnover and subcellular distribution of cyclin D1, which is mediated by IKKα-induced phosphorylation of cyclin D1. Because cyclin D nuclear localization is implicated in tumor development, we examined whether the absence of IKKα leads to tumor development as well. In the current study, we show that IKKα plays a critical role in tumorigenesis. Though IKKα(-/-) MEF cells show a slower anchorage-dependent growth, they are clonogenic in soft agar. These cells are tumorigenic in nude mice. Microarray analysis of IKKα(-/-) cells indicates a differential expression of genes involved in proliferation and apoptosis. Furthermore, analysis of microarray data of human lung cancer cell lines revealed decreased IKKα RNA expression level as compared with cell lines derived from normal bronchial epithelium. These results suggest that IKKα may function as a tumor suppressor gene. Absence of IKKα may induce tumorigenicity by nuclear localization of cyclin D1 and modulating the expression of genes involved in neoplastic transformation.

Relationship between iron deficiency anaemia and serum lipid levels in Indian adults.

Both iron deficiency anaemia and dyslipidaemia are widely prevalent public health problems, especially in the Indian population. Some link has been suggested between the two potentially morbid conditions but a sufficient Indian study could not be found in this regard. This study was planned to find the changes in serum lipid profile in adult Indian patients with iron deficiency anaemia and the effect of oral iron therapy on them. Seventy patients with iron deficiency anaemia and 70 age and sex matched healthy controls, in the age group of 18-35 years were investigated for any possible changes in serum lipid profile ie, triglycerides, total cholesterol, high density lipoprotein cholesterol, very low density lipoprotein cholesterol and low density lipoprotein cholesterol. The patients were followed up after 3 months of oral iron therapy. The results are shown as mean +/- standard deviation. Triglycerides and very low density lipoprotein cholesterol levels were found to be significantly (p < 0.001) elevated in the iron deficiency anaemia group (151.87 +/- 48.06 mg/dl and 30.40 +/- 9.71 mg/dl) as compared to controls (109.99 +/- 30.81 mg/dl and 21.96 +/- 6.69 mg/dl), whereas levels of low density lipoprotein cholesterol were found to be significantly (p = 0.02) lower in patients (90.96 +/- 41.55 mg/dl) as compared to controls (105.24 +/- 26.45 mg/dl). However, after treatment (in 43 patients) there was significant (p < 0.001) reduction in the levels of triglycerides and very low density lipoprotein cholesterol (111.56 +/- 26.87 mg/dl and 22.30 +/- 5.36 mg/dl) when compared to their pretreatment levels (154.70 +/- 53.89 mg/dl and 30.93 +/- 10.84 mg/dl), whereas low density lipoprotein cholesterol levels did not show any significant change. These findings indicate that iron deficiency anaemia in Indian adults is attended by abnormal serum lipid profile, which responds significantly to iron therapy.

An open-label clinical trial evaluating safety and pharmacokinetics of two dosing schedules of panitumumab in patients with solid tumors.

PURPOSE: This study evaluated safety, pharmacokinetics, and efficacy of 2 dose schedules and 2 infusion times of panitumumab in patients with advanced solid malignancies. PATIENTS AND METHODS: This phase I multicenter, open-label study sequentially enrolled patients with advanced solid tumors refractory to standard therapy, or for which no standard therapy exists, to receive panitumumab 6 mg/kg every 2 weeks or 9 mg/kg every 3 weeks. Patients receiving panitumumab every 2 weeks received either all infusions over 60 minutes or a 60-minute infusion for the first dose followed by 30-minute infusions if the first infusion was well tolerated. Patients in the every-3-week cohort received 60-minute infusions. Safety outcomes included the incidence of adverse events and antipanitumumab antibody formation. Pharmacokinetic properties were determined. Efficacy endpoints included response rate and duration of response. RESULTS: Eighty-six patients were enrolled; 84 (98%) received panitumumab. Treatment-related adverse events occurred in 90% of patients. Safety profiles were similar between patients receiving 30-minute (n = 20) and 60-minute (n = 43) infusions every 2 weeks and patients receiving panitumumab every 3 weeks (n = 21). Panitumumab exposure at steady state increased dose proportionally, and peak serum concentrations were similar in patients receiving either 30- or 60-minute infusions every 2 weeks. Objective responses were seen in 4 patients (5%) with colon, rectal, esophageal, and bladder cancers. CONCLUSION: Similar drug exposures and safety profiles were observed in patients receiving panitumumab 6 mg/kg every 2 weeks with either 30- or 60-minute infusions and antitumor activity was seen in some patients. Exposure increased approximately dose proportionally at steady state.

Soluble and insoluble nickel compounds exert a differential inhibitory effect on cell growth through IKKalpha-dependent cyclin D1 down-regulation.

It is well-known that insoluble nickel compounds possess much more potent carcinogenic activities as compared with soluble nickel compounds. Although it is assumed that the different entry and clearance rate are responsible for the difference, the mechanisms underlying the different carcinogenic activities are still not well understood yet. In the present study, we found that exposure to soluble, but not insoluble nickel compounds, caused a significant inhibition of cell growth and G1/G0 cell cycle arrest, which was concomitant with a marked down-regulation of cylin D1, an essential nuclear protein for controlling G1/S transition, while both soluble and insoluble nickel compounds showed similar effects on NFkappaB activation, HIF-1alpha protein accumulation and TNF-alpha transcription and CAP43 protein expression at same doses range. The down-regulation of cyclin D1 is due to protein degradation rather than inhibition of transcription, because the nickel compounds treatment did not change cyclin D1 mRNA level, while MG132, the proteasome inhibitor, can rescue the degradation of cyclin D1 caused by soluble nickel compound. Moreover, the soluble nickel-induced cyclin D1 degradation is dependent on its Thr286 residue and requires IKKalpha, but not HIF-1alpha, which are both reported to be involved in cyclin D1 down-regulation. Taken together, we demonstrate that soluble, but not insoluble nickel compound, is able to cause cyclin D1 degradation and a cell growth arrest in an IKKalpha-dependent manner. Given the role of cyclin D1 and cell proliferation in carcinogenesis, we anticipate that the different effects of soluble and insoluble nickel compounds on cyclin D1 degradation and cell growth arrest may at least partially account for their different carcinogenic activities.

Phase I dose escalation study with irinotecan, capecitabine, epirubicin, and granulocyte colony-stimulating factor support for patients with solid malignancies.

OBJECTIVES: Preclinical studies using sequences of topoisomerase I and II inhibitors suggested synergism; preliminary clinical studies, resulting in enhanced antitumor responses, confirm this in selected malignancies. This study determined the maximum-tolerated dose (MTD), toxicity, and pharmacokinetics of irinotecan (CPT-11), capecitabine, and epirubicin in patients with metastatic adenocarcinoma of lung, breast, or gastrointestinal tract. Correlation of topoisomerase IIbeta was also done. METHODS: Eligibility criteria included the following: documented adenocarcinoma of the lung, breast, or gastrointestinal tract, <3 prior chemotherapy regimens, Eastern Cooperative Oncology Group (ECOG) performance status 0 to 2, age > or =18 years, adequate organ function, and signed informed consent. Irinotecan was administered at 250 mg/m2 intravenously day 1 every 21-day cycle, but was reduced to 180 mg/m2 in cohort 2 due to toxicity. Capecitabine was administered at 750 mg/m2 twice daily days 2 to 14 in cohort 1 but only on days 2 to 7 from cohort 2 due to early neutropenia and to allow for prophylactic granulocyte colony-stimulating factor (GCSF) support. Epirubicin was administered at 40 mg/m2 in cohort 1, but reduced to 30 mg/m2 in cohort 2, then reescalated until the MTD was reached. RESULTS: Toxicity was assessed in 21 patients; response was assessed in 17 patients. The most common grade 3 to 4 toxicities included neutropenia (57.1%) and anemia (28.6%). The MTD of epirubicin was 50 mg/m2. In evaluable patients, there were 2 partial responses (11.8%) and 13 stable disease (76.5%); these correlated well with topoisomerase IIbeta. CONCLUSIONS: The recommended doses for phase II studies: irinotecan 180 mg/m2 day 1, epirubicin 50 mg/m2 day 2, and capecitabine 750 mg/m2 twice daily days 2 to 7 of each 21-day cycle. This combination is reasonably active and warrants evaluation in the phase II setting.

Efficacy of sequential treatment of HCT116 colon cancer monolayers and xenografts with docetaxel, flavopiridol, and 5-fluorouracil.

AIM: Clinical treatment of solid tumors with docetaxel, flavopiridol, or 5-fluorouracil (5-FU) often encounters undesirable side effects and drug resistance. This study aims to evaluate the potential role of combination therapy with docetaxel, flavopiridol, or 5-FU in modulating chemosensitivity and better understand how they might be used clinically. METHODS: HCT116 colon cancer cells were treated with docetaxel, flavopiridol, and 5-FU in several different administrative schedules in vitro, either sequentially or simultaneously. Cell survival was measured by MTT assay. The activity of caspase-3 was determined by caspase-3 assays and the soft agar colony assay was used to test the colony formation of HCT116 cells in soft agar. We also established xenograft models to extend in vitro observations to an in vivo system. RESULTS: The maximum cytotoxicity was found when human colon cancer HCT116 cells were treated with docetaxel for 1 h followed by flavopiridol for 24 h and 5-FU for another 24 h. This sequential combination therapy not only inhibits tumor cell growth more strongly compared to other combination therapies but also significantly reduces colony formation in soft agar and augments apoptosis of HCT116 cells. Sequencing of docetaxel followed 1 h later by flavopiridol, followed 24 h later by 5-FU in xenograft models, also resulted in delayed tumor growth and higher survival rate. CONCLUSION: These results highlight the importance of an administrative schedule when combining docetaxel with flavopiridol and 5-FU, providing a rationale explanation for its development in clinical trials.

IkappaB kinase alpha regulates subcellular distribution and turnover of cyclin D1 by phosphorylation.

IkappaB kinases (IKKs), IKKalpha and IKKbeta, with a regulatory subunit IKKgamma/NEMO constitute a high molecular weight IKK complex that regulates NF-kappaB activity. Although IKKalpha and IKKbeta share structural and biochemical similarities, IKKalpha has been shown to have distinct biological roles. Here we show that IKKalpha plays a critical role in regulating cyclin D1 during the cell cycle. Analysis of IKKalpha-/- mouse embryo fibroblast cells showed that cyclin D1 is overexpressed and localized in the nucleus compared with parental mouse embryo fibroblasts. IKKalpha associates with and phosphorylates cyclin D1. Analysis on cyclin D1 mutants demonstrated that IKKalpha phosphorylates cyclin D1 at Thr286. Reconstitution of IKKalpha in knockout cells leads to nuclear export and increased degradation of cyclin D1. Further, RNAi-mediated knockdown of IKKalpha results in similar changes as observed in IKKalpha-/- cells. These results suggest a novel role of IKKalpha in regulating subcellular localization and proteolysis of cyclin D1 by phosphorylation of cyclin D1 at Thr286, the same residue earlier found to be a target for glycogen synthase kinase-3beta-induced phosphorylation.

Enhanced chemosensitivity to irinotecan by RNA interference-mediated down-regulation of the nuclear factor-kappaB p65 subunit.

In preclinical tumor models, inhibition of nuclear factor-kappaB (NF-kappaB) has been associated with increased sensitivity to chemotherapeutic agents such as irinotecan (CPT-11). This is based on the fact that a variety of chemotherapy agents such as CPT-11 activate NF-kappaB to result in the expression of genes such as c-IAP1 and c-IAP2 that might be responsible for the inhibition of chemotherapy-induced apoptosis. In this study, RNA interference [small interfering RNA (siRNA)] was used to down-regulate the NF-kappaB p65 subunit in the HCT116 colon cancer cell line, and its role, in the presence and absence of CPT-11, was assessed on cell growth and apoptosis. Reduction of endogenous p65 by siRNA treatment significantly impaired CPT-11-mediated NF-kappaB activation, enhanced apoptosis, and reduced colony formation in soft agar. Furthermore, the in vivo administration of p65 siRNA reduced HCT116 tumor formation in xenograft models in the presence but not the absence of CPT-11 administration. These data indicate that the administration of siRNA directed against the p65 subunit of NF-kappaB can effectively enhance in vitro and in vivo sensitivity to chemotherapeutic agents.

Nuclear role of I kappa B Kinase-gamma/NF-kappa B essential modulator (IKK gamma/NEMO) in NF-kappa B-dependent gene expression.

The I kappa B kinase (IKK) complex, which is composed of the two kinases IKK alpha and IKK beta and the regulatory subunit IKK gamma/nuclear factor-kappa B (NF-kappa B) essential modulator (NEMO), is important in the cytokine-induced activation of the NF-kappa B pathway. In addition to modulation of IKK activity, the NF-kappa B pathway is also regulated by other processes, including the nucleocytoplasmic shuttling of various components of this pathway and the post-translational modification of factors bound to NF-kappa B-dependent promoters. In this study, we explored the role of the nucleocytoplasmic shuttling of components of the IKK complex in the regulation of the NF-kappa B pathway. IKK gamma/NEMO was demonstrated to shuttle between the cytoplasm and the nucleus and to interact with the nuclear coactivator cAMP-responsive element-binding protein-binding protein (CBP). Using both in vitro and in vivo analysis, we demonstrated that IKK gamma/NEMO competed with p65 and IKK alpha for binding to the N terminus of CBP, inhibiting CBP-dependent transcriptional activation. These results indicate that, in addition to the key role of IKK gamma/NEMO in regulating cytokine-induced IKK activity, its ability to shuttle between the cytoplasm and the nucleus and to bind to CBP can lead to transcriptional repression of the NF-kappa B pathway.