Paclitaxel and concurrent radiation in upper gastrointestinal cancers

Circular RNA PLEC acts as a sponge of microRNA-198 to promote gastric carcinoma cell resistance to paclitaxel and tumorigenesis

Gastric carcinoma (GC) is one of the most frequent types of malignancy worldwide. Resistance to paclitaxel (PTX) has become an obstacle to the prognosis of GC, and the underlying mechanism is not clear. A previous study identified GC-related circRNAs via microarray analysis and bioinformatics analysis, and we discovered that circPLEC (hsa_circ_104722) was markedly upregulated in GC tissues and cells. The molecular mechanism of circPLEC in PTX-resistant GC cells still needs to be explored. In the present study, qRT-PCR demonstrated that circPLEC was upregulated in PTX-resistant GC tissues and cells, indicating that circPLEC boosts the PTX resistance of GC. circPLEC downregulation weakened GC resistance to PTX and tumorigenesis, migration and invasion and promoted the apoptosis of PTX-resistant GC cells. MiR-198 inhibitor reversed the effect of circPLEC downreguAlation in PTX-resistant GC cells, and MUC19 downregulation weakened GC resistance to PTX and tumorigenesis and improved the apoptosis of PTX-resistant GC cells. In summary, circPLEC acts as a sponge of miR-198 to promote the PTX resistance and tumorigenesis of GC cells by regulating MUC19 expression.

Development and progression of cancer cachexia: Perspectives from bench to bedside

Cancer cachexia (CC) is a devastating syndrome characterized by weight loss, reduced fat mass and muscle mass that affects approximately 80% of cancer patients and is responsible for 22%–30% of cancer-associated deaths. Understanding underlying mechanisms for the development of CC are crucial to advance therapies to treat CC and improve cancer outcomes. CC is a multi-organ syndrome that results in extensive skeletal muscle and adipose tissue wasting; however, CC can impair other organs such as the liver, heart, brain, and bone as well. A considerable amount of CC research focuses on changes that occur within the muscle, but cancer-related impairments in other organ systems are understudied. Furthermore, metabolic changes in organ systems other than muscle may contribute to CC. Therefore, the purpose of this review is to address degenerative mechanisms which occur during CC from a whole-body perspective. Outlining the information known about metabolic changes that occur in response to cancer is necessary to develop and enhance therapies to treat CC. As much of the current evidences in CC are from pre-clinical models we should note the majority of the data reviewed here are from pre-clinical models.

A phase II study of concurrent chemoradiotherapy and erlotinib for inoperable esophageal squamous cell carcinoma

Cisplatin-based concurrent chemoradiotherapy for patients with unresectable, locally advanced esophageal squamous cell carcinoma (ESCC) is associated with significant toxicities that are often intolerable. Prognosis for this subgroup of patients remains poor, and new therapeutic approaches are urgently needed. We investigated the efficacy and safety of paclitaxel combined with erlotinib and concurrent radiotherapy in patients with inoperable ESCC. Erlotinib (150 mg) was administered daily for 60 days beginning at the start of radiotherapy, and paclitaxel (45 mg/m²) was administered weekly along with intensity modulated conformal radiotherapy (60 Gy in 30 fractions). The median follow-up time was 21 months. The associations between EGFR and VEGF expression and treatment outcome were evaluated. Among the 21 patients treated, the overall response rate (CR + PR) was 85.6%. The median LPFS, PFS and OS were: 17.5, 14.3, and 22.9 months, respectively. Treatment-related grade 3 toxicities included esophagitis (two patients) and hypoleukemia (one patient). Grade 4 pulmonary toxicity was observed in one patient. Patients expressing EGFR had longer PFS, while those expressing VEGF or with a history of smoking had worse outcomes. Weekly paclitaxel combined with erlotinib and concurrent radiotherapy shows promise as an effective, tolerated regimen for patients with inoperable ESCC.

Radiotherapy concurrent with paclitaxel plus cisplatin vs 5-fluorouracil plus cisplatin for esophageal cancer

AIM: To compare the efficacy and side effects of paclitaxel plus cisplatin vs cisplatin plus 5-fluorouracil (5-Fu), in combination with concurrent radiation in patients with esophageal cancer.

METHODS: Fifty-three patients who were pathologically diagnosed with esophageal cancer were randomly into two groups. One group of patients were treated with paclitaxel (125 mg/m², d1) combined with cisplatin (20 mg/m², d1-3), and the other group of patients received 5-Fu (500 mg/m², d1-5) combined with cisplatin (20 mg/m², d1-4). Patients in both groups received a concurrent radiotherapy, 2 Gy/d, 5 times/wk, at a total dose of 56-60 Gy. All the patients were followed for one year, and the local control rate, survival rate, and other clinical and laboratory data were compared between the two groups.

RESULTS: The local control rates and one-year survival rates between the two groups were 85.00% vs 89.29% and 76.00% vs 85.71% respectively, which demonstrated no statistically difference. The overall rate of adverse reactions was significantly lower in patients administered with the apaclitaxel-cisplatin regimen than in those treated with cisplatin plus 5-Fu (32.00% vs 53.60%, P > 0.05), while the incidence of neutropenia was more frequent in patients who received the apaclitaxel-cisplatin regimen (60.00% vs 42.86%, P < 0.05).

CONCLUSION: Both paclitaxel-cisplatin and cisplatin-5-Fu regimens, in combination with concurrent radiotherapy, are effective in the treatment of esophageal cancer. Patients receiving paclitaxel-cisplatin regimen are relatively apt to neutropenia, which needs more attention.

A Meta-Analysis of Concurrent Chemoradiotherapy for Advanced Esophageal Cancer

Background

Concurrent chemoradiotherapy is a standard treatment for local advanced esophageal cancer, but the outcomes are controversial. Our goals were to compare the therapeutic effects of concurrent chemoradiotherapy and radiotherapy alone in local advanced esophageal cancer using meta-analysis.

Methods

MEDLINE, EMBASE and the Cochrane library were searched for studies comparing chemoradiotherapy with radiotherapy alone for advanced esophageal cancer. Only randomized controlled trials were included, and extracted data were analyzed with Review Manager Version 5.2. The pooled relative risks (RR) and their 95% confidence intervals (CI) were calculated for statistical analysis.

Results

Nine studies were included. Of 1,135 cases, 612 received concurrent chemoradiotherapy and 523 were treated with radiotherapy alone. The overall response rate (complete remission and partial remission) was 93.4% for concurrent chemoradiotherapy and 83.7% for radiotherapy alone (P = 0.05). The RR values of 1-year, 3-year, and 5-year survival rates were 1.14 (95% CI: 1.04 - 1.24, P = 0.006), 1.66 (95% CI: 1.34 - 2.06, P < 0.001), and 2.43 (95% CI: 1.63 - 3.63, P < 0.001), respectively. The RR value of the merged occurrence rate of acute toxic effects was 2.34 (95% CI: 1.90 - 2.90, P <0.001). There was no difference in the incidence of late toxic effects, which had an RR value of 1.21 (95% CI: 0.96 - 1.54, P = 0.11). The RR level of persistence and recurrence was 0.71 (95% CI: 0.62 - 0.81, P <0.001), and for the distant metastasis rate, the RR value was 0.79 (95% CI: 0.61 - 1.02, P = 0.07).

Conclusions

Concurrent chemoradiotherapy significantly improved overall survival rate, reduced the risk of persistence and recurrence, but had little effect on the primary tumor response, and increased the occurrence of acute toxic effects.

Epidermal growth factor receptor: an important target in esophageal cancer

INTRODUCTION

Even after complete tumor removal by surgery, the clinical outcomes remain poor in patients with advanced esophageal cancer, justifying the need for new treatment options. Epidermal growth factor receptor (EGFR) is a molecular target for antibody-based therapy in various cancer types, and it may play important roles in the development of esophageal cancer.

AREAS COVERED

This review evaluates the expression, function, and mechanism of EGFR in esophageal cancer and analyzes its value for the prognosis and therapy of esophageal cancer. Future developments toward the clinical applications of EGFR to cancer treatment are also envisaged.

EXPERT OPINION

EGFR may function as an ideal therapeutic target for esophageal cancer. Further investigation of epidermal growth-factor-receptor-mediated pathways will push insight into the novel strategies of target therapy for esophageal cancer. More clinical trials should be performed to promote the success of therapeutic-clinical use of EGFR and its targets in esophageal cancer.

Mechanistic study of the covalent loading of paclitaxel via disulfide linkers for controlled drug release

A novel controlled drug-delivery system (CDDS) based on fluorescent mesoporous silica nanoparticles (FMSN) covalently linked with paclitaxel (PTX) via a disulfide linker was designed and characterized. A PTX prodrug based on a disulfide linker was synthesized, and its drug-delivery mechanism was determined through HPLC characterization. Utilizing the carboxyl group of the prodrug, PTX was covalently conjugated to the surface of amino-functionalized FMSN, with a disulfide linker as a spacer to bridge between PTX and FMSN, and the loading content of PTX reached as high as 13% by weight. The most important feature of this nanoscale CDDS is that the PTX prodrug modules conjugated with FMSN can be activated to its cytotoxic form inside the tumor cells upon internalization and in situ drug release. To prove the efficacy of this CDDS, glutathione-mediated intracellular drug delivery was investigated against the HeLa cell line, and the results indicated that our CDDS showed higher cellular proliferation inhibition against glutathione monoester pretreated cells than against untreated cells and the cytotoxicity increased with increasing intracellular glutathione concentration. The result indicates that CDDS can release PTX molecules to kill cancer cells and the release behavior is GSH-dependent. Furthermore, the in vitro evaluation revealed that the FMSN-PTX conjugate could be effectively taken up by HeLa cells. All of these results suggest that this redox-responsive CDDS is potentially useful as a drug-delivery system that can reduce the toxic and side effects of anticancer drugs.

Quality of life and toxicity of stereotactic radiotherapy in pancreatic tumors: a case series

AIM

To analyze the results of extracranial stereotactic radiotherapy (ESRT) experience in pancreatic cancer patients.

METHODS

Four noncoplanar fixed beams were used in all patients.

RESULTS

Analysis of 16 patients was carried out. Overall response rate was 56.2%. Fifteen patients experienced local and/or distant progression of disease (median follow-up: 24 months). Two-year local progression-free, distant progression-free, and overall survivals were 85.7%, 58.7%, and 50.0%, respectively. Toxicity was less than grade 2 in all, although 1 patient had severe duodenal bleeding. Quality of life scores were unchanged.

CONCLUSIONS

ESRT was associated with low complication rate, and not worsening the patients' quality of life.

Amphiregulin regulates the activation of ERK and Akt through epidermal growth factor receptor and HER3 signals involved in the progression of pancreatic cancer

Pancreatic cancer is one of the most lethal malignancies. Epidermal growth factor receptor (EGFR), HER3, Akt, and amphiregulin have been recognized as targets for pancreatic cancer therapy. Although gemcitabine + erlotinib has been the recommended chemotherapy for pancreatic cancer, the prognosis is extremely poor. The development of molecularly targeted therapies has been required for patients with pancreatic cancer. To assess the validation of amphiregulin as a target for pancreatic cancer therapy, we examined its expression in pancreatic cancer using real-time PCR analyses and ELISA. We also measured the apoptotic cell rate using TUNEL assays. In addition, alterations in signaling pathways were detected by immunoblotting analyses. Treatment with gemcitabine, which reduced the cell viability and augmented the cell apoptotic rate, activated and subsequently attenuated ERK and EGFR signals. However, gemcitabine, paclitaxel, or cisplatin treatment enhanced the Akt activation, heterodimer formation of EGFR with HER3, and secretion of amphiregulin, indicating that the presence of gemcitabine promoted the activity of targeted molecules including amphiregulin, Akt, and HER3 for pancreatic cancer therapy. Combined treatment with an inhibitor for amphiregulin and gemcitabine, paclitaxel, or cisplatin induced synergistic antitumor effects, accompanied by the suppression of Akt and ERK activation. Blockade of amphiregulin suppressed the activities of EGFR, HER3, and Akt and the expression of amphiregulin itself. According to this evidence, combination chemotherapy of conventional anticancer drugs plus an inhibitor for amphiregulin would allow us to provide more favorable clinical outcomes for patients with pancreatic cancer.

Paclitaxel chemotherapy for the treatment of gastric cancer

A comprehensive review of phase I and phase II clinical trials of paclitaxel and paclitaxel-containing chemotherapy regimens for advanced gastric cancer was performed. Response rates, median progression-free survivals, and median overall survivals were examined, together with the treatment regimens and the numbers of patients registered in each trial. Although paclitaxel monotherapy produced considerable improvement in tumor response and prognosis, combination doublet or triplet chemotherapy with fluoropyrimidines and/or platinum compounds showed better results than the paclitaxel monotherapy. With regard to the schedule of paclitaxel administration, weekly injection seemed to show less toxicity and better results than administration every 3 weeks. Adjuvant therapies, chemoradiation therapies, and paclitaxel treatment for gastric ascites were also investigated and are discussed.

Phase II studies on docetaxel alone every third week, or weekly in combination with gemcitabine in patients with primary locally advanced, metastatic, or recurrent esophageal cancer

BACKGROUND

The purpose of these studies was to compare efficacy and toxicity of docetaxel alone with the combination of gemcitabine and docetaxel for treatment of metastatic esophageal carcinoma.

PATIENTS AND METHODS

These studies enrolled patients with histopathologically verified squamous cell carcinoma or adenocarcinoma of the esophagus or cardia. Between March 1997 and June 1999, 52 patients were enrolled in the initial Phase II study (Study 1). They were scheduled for treatment with docetaxel 100 mg/m2 every third week as a 1-h infusion. The second Phase II study between September 2000 and March 2003 included 65 patients (Study II). They were given docetaxel 30 mg/m2, administered as a 30-min i.v. infusion weekly for four times, followed by 2 weeks of rest, and gemcitabine starting with a dose of 750 mg/m2 (if well-tolerated 1,000 mg/m2) on days 1 and 15, followed by 3 weeks of rest. A new cycle began on day 36. Patients were premedicated with betamethasone 8 mg p.o. on the evening before, and 8 mg i.v. 30-60 min before the docetaxel infusion. Response was confirmed by computed tomography and assessed at 12 and 24 weeks. Toxicity was assessed according to WHO scales.

RESULTS

In study I, 38 out of the 52 enrolled patients were valuable. Two patients experienced complete remission (CR) (5%), 10 patients partial remission (PR) (26%), nine patients stable disease (SD) (24%), and 17 patients showed progressive disease (PD) (45%). Toxicity mainly involved leukopenia, which in some cases required hospitalization and treatment with antibiotics. In Study II, 46 out of the 65 enrolled patients (70%) were assessable. Out of these, three patients (7%) had CR, eight patients (17%) had PR, 10 patients (22%) had SD, and 25 (54%) PD. Overall response was 24% while an additional 22% showed stable disease. Toxicity mainly consisted of leucopenia and pain.

CONCLUSION

Docetaxel as a single agent is active in esophageal cancer, both in treatment naive and in previously treated patients with recurrent disease. The overall response rate was 31%, with a good-safety profile. The addition of gemcitabine is well tolerated, but adds no efficacy. Weekly administration of docetaxel may be less effective. It demonstrates moderate efficacy and the doses used provide an acceptable safety profile.

Paclitaxel prodrugs with sustained release and high solubility in poly(ethylene glycol)-b-poly(epsilon-caprolactone) micelle nanocarriers: pharmacokinetic disposition, tolerability, and cytotoxicity

PURPOSE

Develop a Cremophor and solvent free formulation of paclitaxel using amphiphilic block co-polymer micelles of poly(ethylene glycol)-b-poly(epsilon-caprolactone) (PEG-b-PCL) and characterize their release, solubility, cytotoxicity, tolerability, and disposition.

METHODS

Hydrophobic prodrugs of paclitaxel were synthesized via DCC/DMAP or anhydride chemistry to overcome the poor loading (<1% w/w) of paclitaxel in micelles of PEG-b-PCL. Micelles were prepared by a co-solvent extraction technique. A micellar formulation of paclitaxel prodrug (PAX7'C(6)) was dosed intravenously to rats (10 mg/kg) and compared to Taxol (paclitaxel in CrEL:EtOH) and PAX7'C(6) in CrEL:EtOH as controls at the same dose. Pharmacokinetic parameters and tissue distribution were assessed.

RESULTS

Paclitaxel prodrugs had solubilities >5 mg/ml in PEG-b-PCL micelles. Resulting PEG-b-PCL micelles contained 17-22% w/w prodrug and were less than 50 nm in diameter. PEG-b-PCL micelles released paclitaxel prodrugs over several days, t(1/2)>3 d. Only the 7'derivative of paclitaxel with the shortest acylchain 7'hexonoate (PAX7'C(6)) maintained cytotoxic activity similar to unmodified paclitaxel. PAX7'C(6) micelles demonstrated an increase in area under the curve, half-life, and mean residence time while total clearance and volume of distribution decreased.

CONCLUSIONS

Paclitaxel prodrugs in PEG-b-PCL micelle nanocarriers augment the disposition and increase tolerability making further studies on tumor efficacy warranted.

Paclitaxel and concomitant radiotherapy in high-risk endometrial cancer patients: preliminary findings

Background

There is still much debate about the best adjuvant therapy after surgery for endometrial cancer (EC) and there are no current guidelines. Radiotherapy (RT) alone does not seem to improve overall survival. We investigated whether concomitant Paclitaxel (P) and RT gave better clinical results.

Methods

Twenty-three patients with high-risk EC (stage IIB, IIIA, IIIC or IC G3 without lymphadenectomy or with aneuploid tumor) underwent primary surgery and were then referred for adjuvant therapy. P was given at a dose of 60 mg/m2 once weekly for five weeks during RT, which consisted of a total radiation dose of 50.4 Gy. Three further weekly cycles of P at a dose of 80 mg/m2 were given at the end of RT. Overall survival and disease-free survival were calculated from the time of surgery. Patterns of failure were recorded by the sites of failure.

Results

A total of 157 cycles of P were administered both during radiotherapy and consolidation chemotherapy.

Relapses occurred in five patients (21.7%). Median time to recurrence was 18.6 months (range 3–28). Survival rate for all the patients was 78.2%. Overall survival for the patients who completed chemo-radiation was of 81%. In this group median time to recurrence was 19.2 months (range 3–28). All recurrences were outside the radiation field. Mortality rate was 14.2%.

Conclusion

This small series demonstrates pelvic radiotherapy in combination with weakly P followed by three consolidation chemotherapy cycles as an effective combined approach in high risk endometrial carcinoma patients.

Targeting NF-kappaB in anticancer adjunctive chemotherapy

After more than three decades of its declaration, the war against cancer still appears far from being won. Although there have been decisive victories in a few battles, such as the one against testicular cancer, the overall result is sobering. Hopes for an imminent cure had been raised among the public by the promises of molecular biology, combinatorial chemistry and high-throughput screening. These promises have manifested themselves in the widely proclaimed strategy of rationally targeted anticancer drug discovery, which may be summarized as the 'one-gene-one target-one drug' approach. Over the years, however, it has gradually become clear that, in most cases, treatment of cancer with a single drug may at best delay progression of the disease but is unlikely to lead to a cure. Thus, it appears that rationally targeted monotherapy will have to be replaced by rationally targeted combination therapy. Inhibitors of NF-kappaB look likely to become an important weapon in the anticancer combination therapy arsenal.

CF101, an agonist to the A3 adenosine receptor, enhances the chemotherapeutic effect of 5-fluorouracil in a colon carcinoma murine model

NF-kappaB and the upstream kinase PKB/Akt are highly expressed in chemoresistance tumor cells and may hamper the apoptotic pathway. CF101, a specific agonist to the A3 adenosine receptor (A3AR), inhibits the development of colon carcinoma growth in cell cultures and xenograft murine models. Because CF101 has been shown to downregulate PKB/Akt and NF-kappaB protein expression level, we presumed that its combination with chemotherapy will enhance the antitumor effect of the cytotoxic drug. In this study, we utilized 3-[4,5-Dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) and colony formation assays and a colon carcinoma xenograft model. It has been shown that a combined treatment of CF101 and 5-fluorouracil (5-FU) enhanced the cytotoxic effect of the latter on HCT-116 human colon carcinoma cell proliferation and tumor growth. Downregulation of PKB/Akt, NF-kappaB, and cyclin D1, and upregulation of caspase-3 protein expression level were observed in cells and tumor lesions on treatment with a combination of CF101 and 5-FU. Moreover, in mice treated with the combined therapy, myelotoxicity was prevented as was evidenced by normal white blood cell and neutrophil counts. These results show that CF101 potentiates the cytotoxic effect of 5-FU, thus preventing drug resistance. The myeloprotective effect of CF101 suggests its development as an add-on treatment to 5-FU.

A simultaneous assessment of CYP3A4 metabolism and induction in the DPX-2 cell line

The DPX-2 cell line, a derivative of HepG2 cells, harbors human PXR and a luciferase-linked CYP3A4 promoter. These cells were used in a panel of cell-based assays for a parallel assessment of CYP3A4 induction, metabolism, and inhibition at the cellular level. CYP3A4 induction in the DPX-2 cell line by various agents was monitored in 96-well plates by a luciferase-based transcriptional activation assay. Of the prototypical CYP3A4 inducers examined, all exhibited elevated luciferase activity in DPX-2 cells. CYP3A4 enzyme activity in noninduced and rifampicin-induced DPX-2 cells was also assessed using Vivid fluorogenic substrates. Significantly elevated CYP3A4 activity levels (2.8-fold +/- 0.2-fold above DMSO-treated cells) were found in DPX-2 cells after 48 hours of exposure to rifampicin, but were undetectable in parental HepG2 cells. Rifampicin-induced activity levels were found to be suitable for assessing the inhibitory potential of new chemical entities in downstream CYP3A4 inhibition assays. The elevated CYP3A4 activity was inhibited 85% by 10 microM ketoconazole. In addition, a cytotoxicity assay to correct for possible toxic effects of compounds at the cellular level was applied. The comparative data obtained with a combination of the above assays suggests that the application of several independent in vitro technologies used in DPX-2 cells is the best possible strategy for the assessment of the complex phenomena of CYP3A4 induction and inhibition.