S-phase modulation by irinotecan: pilot studies in advanced solid tumors

Down-regulation of tenascin-C inhibits breast cancer cells development by cell growth, migration, and adhesion impairment

Tenascin-C (TNC) is an extracellular matrix (ECM) glycoprotein that plays an important role in cell proliferation, migration, and tumour invasion in various cancers. TNC is one of the main protein overexpressed in breast cancer, indicating a role for this ECM molecule in cancer pathology. In this study we have evaluated the TNC loss-off-function in breast cancer cells. In our approach, we used dsRNA sharing sequence homology with TNC mRNA, called ATN-RNA. We present the data showing the effects of ATN-RNA in MDA-MB-231 cells both in monolayer and three-dimensional culture. Cells treated with ATN-RNA were analyzed for phenotypic alterations in proliferation, migration, adhesion, cell cycle, multi-caspase activation and the involvement in epithelial to mesenchymal transition (EMT) processes. As complementary analysis the oncogenomic portals were used to assess the clinical implication of TNC expression on breast cancer patient's survival, showing the TNC overexpression associated with a poor survival outcome. Our approach applied first in brain tumors and then in breast cancer cell lines reveals that ATN-RNA significantly diminishes the cell proliferation, migration and additionally, reverses the mesenchymal cells phenotype to the epithelial one. Thus, TNC could be considered as the universal target in different types of tumors, where TNC overexpression is associated with poor prognosis.

Irinotecan and capecitabine combination chemotherapy in a patient with triple-negative breast cancer relapsed after adjuvant chemotherapy with anthracycline and taxane

The most effective regimen for taxane- and anthracycline-refractory triple-negative breast cancer (TNBC) has not yet been established. Capecitabine was approved by the US Food and Drug Administration for the treatment of advanced breast cancer and has shown efficacy in advanced breast cancer refractory to anthracyclines and taxanes. Irinotecan has synergism with 5-fluorouracil and shows efficacy in advanced breast cancer. Here we report on a patient with TNBC who relapsed with widespread bone and lung metastases shortly after adjuvant anthracycline followed by taxane chemotherapy. She achieved a metabolic complete response with irinotecan and capecitabine combination therapy and had 10 months' progression-free survival and 22 months' overall survival. She relapsed with and died of brain metastasis without any definite signs of progression of the lung and bone lesions she had had before the irinotecan and capecitabine combination therapy. To validate this favorable result, larger clinical trials are warranted in patients with metastatic or relapsed TNBC.

Gallotannin imposes S phase arrest in breast cancer cells and suppresses the growth of triple-negative tumors in vivo

Triple-negative breast cancers are associated with poor clinical outcomes and new therapeutic strategies are clearly needed. Gallotannin (Gltn) has been previously demonstrated to have potent anti-tumor properties against cholangiocarcinoma in mice, but little is known regarding its capacity to suppress tumor outgrowth in breast cancer models. We tested Gltn for potential growth inhibitory properties against a variety of breast cancer cell lines in vitro. In particular, triple-negative breast cancer cells display higher levels of sensitivity to Gltn. The loss of proliferative capacity in Gltn exposed cells is associated with slowed cell cycle progression and S phase arrest, dependent on Chk2 phosphorylation and further characterized by changes to proliferation related genes, such as cyclin D1 (CcnD1) as determined by Nanostring technology. Importantly, Gltn administered orally or via intraperitoneal (IP) injections greatly reduced tumor outgrowth of triple-negative breast cells from mammary fat pads without signs of toxicity. In conclusion, these data strongly suggest that Gltn represents a novel approach to treat triple-negative breast carcinomas.

Phase II study of irinotecan plus capecitabine in anthracycline- and taxane- pretreated patients with metastatic breast cancer

To evaluate the efficacy and tolerability of combined treatment with irinotecan (I) and capecitabine (X), we conducted a phase II study of the IX combination in anthracycline- and taxane-pretreated patients with metastatic breast cancer (MBC). Patients received 80 mg/m(2) I on days 1 and 8 and 1,000 mg/m(2) X twice daily on days 1-14 of 21-day cycles until disease progression. The primary endpoint was the objective response rate (ORR), and the secondary endpoints were progression-free survival (PFS), overall survival (OS), and safety. Thirty-six patients were enrolled between September 2006 and April 2008. The median follow-up was 47.6 months. The ORR was 58.3 % (95 % CI, 42.2-72.9), with 3 complete responses and 18 partial responses. The median PFS was 7.6 months (95 % CI, 5.0-10.2), and the median OS was 20.0 months (95 % CI, 11.6-28.4). Neutropenia was the most common adverse event (grade 3, 30.6 %; grade 4, 27.8 %) with febrile neutropenia in 2 patients (5.6 %). Three patients (8.3 %) had grade 3 diarrhea, 3 patients (8.3 %) had grade 3 asthenia, and 1 patient (2.8 %) had grade 3 hand-foot syndrome. The IX combination was effective and tolerable for anthracycline- and taxane-pretreated patients with MBC. A phase III trial of this combination is ongoing.

Cucurbitacin E Induces G(2)/M Phase Arrest through STAT3/p53/p21 Signaling and Provokes Apoptosis via Fas/CD95 and Mitochondria-Dependent Pathways in Human Bladder Cancer T24 Cells

Cucurbitacin E, a tetracyclic triterpenes compound extracted from cucurbitaceous plants, has been shown to exhibit anticancer and anti-inflammatory activities. The purpose of this study was to elucidate whether cucurbitacin E promotes cell cycle arrest and induces apoptosis in T24 cells and further to explore the underlying molecular mechanisms. The effects of cucurbitacin E on T24 cell's growth and accompanied morphological changes were examined by MTT assay and a phase-contrast microscope. DNA content, mitochondrial membrane potential (ΔΨ_m) and annexin V/PI staining were determined by flow cytometry. The protein levels were measured by Western blotting. Our results demonstrated that cucurbitacin E-induced G₂/M arrest was associated with a marked increase in the levels of p53, p21 and a decrease in phospho-signal transducer and activator of transcription 3 (STAT3), cyclin-dependent kinase 1 (CDK1) and cyclin B. Cucurbitacin E-triggered apoptosis was accompanied with up-regulation of Fas/CD95, truncated BID (t-BID) and a loss of ΔΨ_m, resulting in the releases of cytochrome c, apoptotic protease activating factor 1 (Apaf-1) and apoptosis-inducing factor (AIF), and sequential activation of caspase-8, caspase-9, and caspase-3. Our findings provided the first evidence that STAT3/p53/p21 signaling, Fas/CD95 and mitochondria-dependent pathways play critical roles in cucurbitacin E-induced G₂/M phase arrest and apoptosis of T24 cells.

Oxaliplatin but not irinotecan impairs posthepatectomy liver regeneration in a murine model

Introduction. We examined the murine hepatectomy model of liver regeneration (LR) in the setting of neoadjuvant chemotherapy. Methods. C57BL/6 mice were randomized to receive neoadjuvant intraperitoneal (IP) injections of a control, oxaliplatin (15 mg/kg), or irinotecan (100 mg/Kg or 250 mg/Kg) solution. Hepatectomy (70%) was performed 14 days after the final IP treatment. Animals were sacrificed at postoperative day (D) 0, 1, 2, 3, and 7. Liver remnants and serum were collected for analysis. T-tests for independent samples were used for statistical comparisons. Results. For oxaliplatin, percent LR did not differ at D1 or D2 but was significantly less at D3 (89.0% versus 70.0%, P = 0.048) with no difference on D7 (P = 0.21). Irinotecan-treated mice at both dose levels (100 mg/Kg and 250 mg/Kg) showed no significant differences in LR. BrdU incorporation was significantly decreased in oxaliplatin-treated animals (D1,2,3). Conclusions. Neoadjuvant oxaliplatin but not irinotecan impairs early LR in a posthepatectomy murine model which correlates with decreased DNA synthesis.

Scheduled administration of low dose irinotecan before gemcitabine in the second line therapy of non-small cell lung cancer: a phase II study

We had previously demonstrated that low dose irinotecan (CPT-11) leads to increased accumulation of cells in S-phase and shows a therapeutic synergy with S-phase specific chemotherapy such as gemcitabine and 5-fluorouracil. In this phase II study, our objectives were to evaluate the tolerability and activity of low dose CPT-11 followed 24 h later by gemcitabine as second line therapy in patients with metastatic non-small cell lung cancer (NSCLC). CPT-11 (60 mg/m) was administered 24 h before gemcitabine (1000 mg/m) on days 1, 2, 8, and 9 every 3 weeks. Twenty-nine patients were evaluable for response. The median follow-up was 7.4 months. Partial response (PR) was seen in two (6.9, 95% confidence interval (CI): 0.009-0.228). PR and stable disease were seen in 22 patients (75.9, 95% CI: 0.564-0.897). The median survival time was 13.8 months (95% CI: 8.1-19.3). The median time to progression was 4.6 months (95% CI: 2.6-6.2). Thirty-eight patients were evaluable for toxicity. Neutropenia (grade 3 or 4) was observed in 27 patients (71%). Eight patients did not receive cycle 2 of therapy owing to prolonged neutropenia. No treatment-related deaths occurred. Scheduled administration of low dose CPT-11, 24 h before gemcitabine in the second line therapy of NSCLC yielded comparable disease control rates (PR and stable disease) when compared with other studies using the two chemotherapy drugs in the traditional sequence. However, this approach was associated with higher grade 3/4 neutropenia and is not recommended for further study in metastatic NSCLC.

Mana-Hox displays anticancer activity against prostate cancer cells through tubulin depolymerization and DNA damage stress

Tubulin and deoxyribonucleic acid (DNA) are two potential targets for the development of cancer chemotherapeutic agents. Mana-Hox is a synthetic derivative of beta-carboline, a structure relevant to marine sponge component, manzamine. In this study, Mana-Hox induced an inhibition of cell proliferation in several types of human cancer cell lines, including androgen-independent prostate cancer PC-3 and DU-145, hepatocellular carcinoma Hep3B and HepG2, and colorectal cancer HT-29 cells. The p53-null PC-3 cells were used for to anticancer mechanisms. Mana-Hox stimulated an increase of ataxia telangiectasia mutated (ATM) phosphorylation on Ser-1981, indicating the induction of DNA double-strand breaks. It also displayed an inhibitory effect on tubulin polymerization using tubulin turbidity assay and immunofluorescence identification. However, it only showed a minor inhibition on the activity of Aurora kinase and histone deacetylase. Mana-Hox induced mitotic arrest of the cell cycle identified by downregulation of cyclin E, cyclin A, and cyclin-dependent kinase 2 (Cdk2) and an increase of MPM-2 expression. Next, it caused Bcl-2 phosphorylation on Ser-70, downregulation of Mcl-1 expression, and activation of caspase-3, leading to apoptotic cell death. Notably, Mana-Hox was not a P-glycoprotein (P-gp) substrate and showed equipotent activity against P-gp-rich cancer cells. We conclude that Mana-Hox induces dual effects on DNA damage and tubulin depolymerization, leading to mitotic arrest and activation of mitochondria-mediated apoptotic pathways. Data provide evidence that the anticancer strategy of dual-action targets could be a potential anticancer approach.

Phase I Study of Irinotecan and Gemcitabine in Previously Untreated Patients with Advanced Non-small Cell Lung Cancer

BACKGROUND

Irinotecan and gemcitabine are effective against non-small cell lung cancer. We conducted a phase I study of the combined use of irinotecan and gemcitabine in previously untreated patients with advanced non-small cell lung cancer to determine dose-limiting toxicities and maximum tolerated dose.

METHODS

Patients were treated with irinotecan followed by gemcitabine on days 1 and 8 every 3 weeks. Gemcitabine dose was fixed at 1000 mg/m2, and irinotecan dose was increased from 60 mg/m2.

RESULTS

A total of 16 patients was enrolled. Maximum tolerated dose of irinotecan was determined up to level 3 (irinotecan 100 mg/m2). In Japan, the maximum approved weekly dose of irinotecan is 100 mg/m2, so this was the dose that was used. Only very mild hematological and non-hematological toxicities were noted.

CONCLUSION

Use of 100 mg/m2 irinotecan followed by 1000 mg/m2 gemcitabine on days 1 and 8 every 3 weeks warrants a phase II study.

A phase I study of capecitabine and a modulatory dose of irinotecan in metastatic breast cancer

PURPOSE

There is a need for chemotherapy regimens active against anthracycline- and taxane-refractory breast cancer. Data from preclinical and pilot studies performed at Roswell Park Cancer Institute (RPCI) suggested that when irinotecan (IRN) is given with 5-fluorouracil (5-FU) efficacy is affected by the sequence of drug administration. Pretreatment with IRN 24 h before 5-FU increased the number of tumor cells in S-phase and the antitumor activity in a preclinical system. These data provided the rationale for the evaluation of IRN and capecitabine, a 5-FU prodrug, sequentially administered in patients with metastatic breast cancer. The main objective of the study was to determine the MTD and identify dose-limiting toxicities (DLTs) of capecitabine and IRN. Additionally, the degree of accumulation of cells in S-phase in tumor biopsies obtained at 24 h after the first dose of IRN was measured in consenting patients.

PATIENTS AND METHODS

Metastatic breast cancer patients who experienced disease progression after at least one (taxane or anthracycline based) chemotherapy regimen and an expected survival of at least 3 months and ECOG performance status 0-2 were eligible. Twelve patients were enrolled and treated. The starting doses were IRN 80 mg/m(2) given over 90 min on days 1, 8, 22, 29, and capecitabine 1,500 mg/m(2)/day given days 2-15 and 23-36. Evaluation for response was performed after the first cycle. Sequential tumor biopsies were performed on five patients.

RESULTS

The first three patients treated exhibited modulation in cyclin A index on tumor biopsy as defined by the study, defining the modulatory dose of IRN as 80 mg/m(2). Overall, 4/5 biopsies showed modulation. Dose Limiting Toxicities (DLTs) were assessed during the first cycle of therapy. Two DLTs (Grade 3 nausea vomiting and dehydration; grade 3 pneumonia, hypoxia, hypotension) were seen at dose level 2 of capecitabine (2,000 mg/m(2)/day) and the first cohort was expanded. There were no DLTs for patients treated at DL 1. No grade 3-4 toxicities occurred at DL 1. Seven patients were evaluable for response following one cycle of treatment (partial response 1, stable disease 4, progressive disease 2) Of the five inevaluable patients, two experienced DLT, one received 50% of the planned capecitabine dose, one progressed prior to evaluation, and one withdrew consent.

CONCLUSION

IRN 80 mg/m(2) days 1, 8, 22, 29 in combination with capecitabine 1,500 mg/m(2)/day in divided dose days 2-15 and 23-36 has an acceptable toxicity profile and resulted in modulation of S-phase in 4/5 specimens examined. Further studies of the activity of this combination and modulatory effect of IRN are warranted.