Gemcitabine chemotherapy for the treatment of metastatic bladder carcinoma

Revealing the impact of modified modules flexibility on gemcitabine prodrug nanoassemblies for effective cancer therapy

Prodrug nanoassemblies combine the advantages of prodrug strategies and nanotechnology have been widely utilized for delivering antitumor drugs. These prodrugs typically comprise active drug modules, response modules, and modification modules. Among them, the modification modules play a critical factor in improving the self-assembly ability of the parent drug. However, the impact of the specific structure of the modification modules on prodrug self-assembly remains elusive. In this study, two gemcitabine (GEM) prodrugs are developed using 2-octyl-1-dodecanol (OD) as flexible modification modules and cholesterol (CLS) as rigid modification modules. Interestingly, the differences in the chemical structure of modification modules significantly affect the assembly performance, drug release, cytotoxicity, tumor accumulation, and antitumor efficacy of prodrug nanoassemblies. It is noteworthy that the prodrug nanoassemblies constructed with flexible modifying chains (OD) exhibit improved stability, faster drug release, and enhanced antitumor effects. Our findings elucidate the significant impact of modification modules on the construction of prodrug nanoassemblies.

A phase II study of neoadjuvant chemotherapy followed by organ preservation in patients with muscle-invasive bladder cancer

Objective

Conservative approaches in muscle-invasive bladder cancer (MIBC) have been evolved to avoid aggressive surgery, but are limited to elderly, frail, and patients medically unfit for surgery. Our study aimed to assess the response rate of neoadjuvant chemotherapy (NACT) before radiotherapy (RT) in MIBC patients.

Methods

Forty patients with urothelial carcinoma of stage T2–T4a, N0, M0 were enrolled between November 2013 and November 2015, and treated with three cycles of NACT with gemcitabine-cisplatin. Post-NACT response was assessed using Response Evaluation Criteria in Solid Tumors (RECIST) criteria. Patients who achieved complete response (CR) and partial response (PR) >50% were treated with radical RT, and those who had PR <50%, stable disease (SD), and progressive disease (PD) underwent radical cystectomy (RC). Survival analysis was done with Kaplan-Meier method and point-to-time events were analyzed with Cox-proportional hazards regression model.

Results

After NACT, 35 (87.5%) patients achieved either PR >50% or CR, and were treated with RT. Five (12.5%) patients who had PR <50%, SD, or PD underwent RC. All patients who received radiation showed CR after 6 weeks. Median follow-up was 43 months (range: 10–66 months) and median overall survival (OS) was not reached. Three-year OS, local control, and disease-free survival were 70.1%, 60.9%, 50.6%, respectively, and 50% of patients preserved their functioning bladder. Three-year OS rate was 88.9% in patients who achieved CR to NACT, 73.1% in patients with PR ≥50% and 40% in patients with PR <50%.

Conclusion

NACT followed by RT provides a high probability of local response with bladder preservation in CR patients. Appropriate use of this treatment regimen in carefully selected patients may omit the need for morbid surgery.

Histologically confirmed distant metastatic urothelial carcinoma from the urinary bladder: a retrospective review of one institution's 20-year experience

Background

Urothelial carcinoma (UC) accounts for roughly 90% of bladder cancer, and has a high propensity for diverse differentiation. Recently, certain histologic variants of UC have been recognized to be associated with unfavorable clinical outcomes. Several UC studies have also suggested that tumor budding is a poor prognostic marker. Distant metastasis of UC after radical cystectomy is not uncommon. However, these metastatic lesions are not routinely confirmed with histology.

Methods

We investigated the histopathologic features of 13 cases of UC with biopsy-proven distant metastases, with a special emphasis on histologic variants and tumor budding.

Results

Lymph nodes (6/13, 46%) were the most common metastatic sites, followed by the lung (4/13, 31%), liver (4/13, 31%), and the adrenal gland (2/13, 15%). The histologic variants including squamous (n = 1), micropapillary (n = 4), and plasmacytoid (n = 1) variants in five cases of UC. Most histologic variants (4/5, 80%) of primary UCs appeared in the metastatic lesions. In contrast, high-grade tumor budding was detected in six cases (46%), including one case of non-muscle invasive UC. Our study demonstrates that histologic variants are not uncommonly detected in distant metastatic UCs. Most histologic variants seen in primary UCs persist in the distant metastatic lesions. In addition, high-grade tumor budding, which occurs frequently in primary tumors, may contribute to the development of distant metastasis.

Conclusions

Therefore, assessing the presence or absence of histologic variants and tumor budding in UCs of the urinary bladder, even in non-muscle invasive UCs, may be useful to predict distant metastasis.

Gemcitabine maintenance versus observation after first-line chemotherapy in patients with metastatic urothelial carcinoma: a retrospective study

Background

Gemcitabine with platinum is one of the most important first-line treatments for metastatic urothelial cancer (mUC). However, continuation of platinum agents results in cumulative toxicities, such as nephrotoxicity, ototoxicity, and neurotoxicity, which lead to discontinuation of chemotherapy after 4–6 cycles despite a favorable response in the patients. The strategy of maintenance treatment can give clinical benefit to patients, but there is no consensus about maintenance treatment. The aim of this study was to investigate the clinical impact of the gemcitabine maintenance (GEM-m) in mUC patients who achieve disease control from first-line gemcitabine with platinum agents.

Methods

A total of 117 patients who showed response to 4–6 cycles of gemcitabine plus cisplatin or carboplatin as the first-line palliative chemotherapy were reviewed between 2014 to 2018. Patients who were treated with GEM-m received a 1,000 mg/m² dose of gemcitabine on day 1 and 8 for 3 weeks until disease progression or development of unacceptable toxicity. The patients who are not treated with GEM-m were followed up with regular radiologic evaluation. Statistical analyses were performed using the log-rank test and Cox proportional hazards method.

Results

Fifty-eight patients (49.6%) received GEM-m. The median cycle of GEM-m was 4 (range, 1–12). Six patients (10.3%) in the GEM-m group showed an objective response. A median overall survival (OS) of 11.8 months and 9.6 months was observed for the GEM-m and non-GEM-m groups, respectively [HR 0.621; 95% CI, 0.39–0.97; P=0.026]. Additionally, median progression-free survival (PFS) was 4.6 months and 3.3 months in the GEM-m and non-GEM-m groups, respectively [HR 0.612; 95% CI, 0.41–0.91; P=0.009]. Grade 3 or higher neutropenia occurred in 17.2% of patients in the GEM-m and 1.7% in the non-GEM-m group.

Conclusions

Our results suggest that GEM-m can be considered in patients who respond to gemcitabine with platinum. Large-scale prospective study should be warranted.

Detection of carcinogen-induced bladder cancer by fluorocoxib A

BACKGROUND

Conventional cystoscopy can detect advanced stages of bladder cancer; however, it has limitations to detect bladder cancer at the early stages. Fluorocoxib A, a rhodamine-conjugated analog of indomethacin, is a novel fluorescent imaging agent that selectively targets cyclooxygenase-2 (COX-2)-expressing cancers.

METHODS

In this study, we have used a carcinogen N-butyl-N-4-hydroxybutyl nitrosamine (BBN)-induced bladder cancer immunocompetent mouse B6D2F1 model that resembles human high-grade invasive urothelial carcinoma. We evaluated the ability of fluorocoxib A to detect the progression of carcinogen-induced bladder cancer in mice. Fluorocoxib A uptake by bladder tumors was detected ex vivo using IVIS optical imaging system and Cox-2 expression was confirmed by immunohistochemistry and western blotting analysis. After ex vivo imaging, the progression of bladder carcinogenesis from normal urothelium to hyperplasia, carcinoma-in-situ and carcinoma with increased Ki67 and decreased uroplakin-1A expression was confirmed by histology and immunohistochemistry analysis.

RESULTS

The specific uptake of fluorocoxib A correlated with increased Cox-2 expression in progressing bladder cancer. In conclusion, fluorocoxib A detected the progression of bladder carcinogenesis in a mouse model with selective uptake in Cox-2-expressing bladder hyperplasia, CIS and carcinoma by 4- and 8-fold, respectively, as compared to normal bladder urothelium, where no fluorocoxib A was detected.

CONCLUSIONS

Fluorocoxib A is a targeted optical imaging agent that could be applied for the detection of Cox-2 expressing human bladder cancer.

DFT and Thermal Decomposition Studies on Gemcitabine

Geometry optimization of gemcitabine was carried out by DFT with B3LYP/6-311++G(d,p) level in the gas phase. Chemical activity (electronegativity, electrophilicity, hardness, chemical softness and chemical potential) was predicted with the help of HOMO-LUMO energy values. Experimental FT-IR was recorded and computed values are also analyzed using the same level of DFT. A complete vibrational spectrum was made to analyze the potential energy distribution (PED). Stability of the molecule arising from the hyper-conjugative interaction was analyzed by the natural bond orbital (NBO). The molecular electrostatic potential map was used to detect the possible electrophilic and nucleophilic sites in the molecule. Nonisothermal decomposition of gemcitabine was carried out in an air atmosphere. The two decomposition steps of the molecule were analyzed kinetically by linear and nonlinear methods for elucidation of the kinetic triplet (Ea , ln A and f(α)) of the decomposition processes. Powder X-ray diffraction indicated that gemcitabine crystallizes in the monoclinic system (SG P2/m). Molecular docking studies were also described.

Electrochemical molecularly bioimprinted siloxane biosensor on the basis of core/shell silver nanoparticles/EGFR exon 21 L858R point mutant gene/siloxane film for ultra-sensing of Gemcitabine as a lung cancer chemotherapy medication

In search for improvements in bioanalysis electrochemical sensors, for better assessment of anti-cancer drugs, it is necessary for their detection limits to be minimized and the sensitivity and selectivity to be surpassed simultaneously; whereas, resolving any probable interfering with other medical treatments are considered. In this work, a novel approach was adopted for detection and assessment of Gemcitabine (GEM) as an anti-cancer drug based on evaluating its interaction with EGFR exon 21-point mutant gene. An electrochemical nanobiosensor was invented based on a new molecularly bioimprinted siloxane polymer (MBIS) strategy; in which the EGFR exon 21 acts as an identification probe. The roles of multi-walled carbon nanotubes and Ag nanoparticles (NPs) are to perform as a signal amplifier. The MBIS film was prepared by acid-catalysed hydrolysis/condensation of the sample solution, containing Ag NPs, ds-DNA of EGFR exon 21 point mutant gene, GEM as a template molecule, 3-(aminopropyl) trimethoxysilane (APTMS) and tetraethoxysilane. The interaction between the dsDNA and GEM was investigated by employing the modified biosensor and monitoring oxidation signal of guanine and adenine. The produced biosensor was characterized by XRD, FE-SEM, EDS, FT-IR and differential pulse voltammetry. The oxidation signals of adenine and guanine were in linear range when the device was subjected to various concentrations of GEM, from 1.5 to -93 μM, where a low detection limit 12.5 nmol L^-1, and 48.8 nmol L^-1 were recorded by guanine and adenine respectively. The developed biosensor did perform very well when employed for the actual samples; the stability was also approved which was acceptable for a reasonable time.

Neoadjuvant Chemotherapy Before Bladder-Sparing Chemoradiotherapy in Patients With Nonmetastatic Muscle-Invasive Bladder Cancer

BACKGROUND

Cisplatin-based neoadjuvant chemotherapy (NAC) before cystectomy improves survival in muscle-invasive urothelial bladder cancer (MIBC). The use of NAC before chemoradiation (CRT) has been limited, as these patients are often elderly, frail, and ineligible for cisplatin. However, the role of NAC in fit, cisplatin-eligible patients who opt for bladder preservation warrants further evaluation.

PATIENTS AND METHODS

Patients with MIBC treated with NAC followed by CRT at the Princess Margaret and Durham Regional cancer centers from 2008 to 2017 were retrospectively reviewed. Gemcitabine-cisplatin NAC was given for 2 to 4 cycles, followed by reassessment for CRT. External-beam radiotherapy (60-66 Gy) over 6 weeks was given with concurrent weekly cisplatin at 40 mg/m². Kaplan-Meier method was used for survival analyses.

RESULTS

We identified 57 consecutive patients. Median age was 72 (range 45-87), and all had an Eastern Cooperative Oncology Group performance status of 0 (60%) or 1 (40%). Stage II disease (65%), stage III disease (25%), and regional nodal metastases (11%) were included. Most completed planned NAC (95%). All patients completed external-beam radiotherapy, and 84% completed at least 60% of the planned concurrent weekly cisplatin doses. Median (range) follow-up was 19.3 (4.8-96.1) months. Median overall survival (OS) was not reached. Two-year OS and disease-specific survival rates were 74% (95% confidence interval, 57.7-84.9) and 88% (95% confidence interval, 78.5-98.1), respectively. Two-year bladder-intact disease-free survival was 64%. Salvage cystectomy was performed in 14%. Distant relapse occurred in 11%, and 9% died of metastatic disease. OS was associated with baseline hydronephrosis and with bladder-intact disease-free survival with residual disease on cystoscopy.

CONCLUSION

NAC followed by CRT can result in encouraging outcomes and tolerability in cisplatin-eligible patients.

Polymer nanoassemblies with solvato- and halo-fluorochromism for drug release monitoring and metastasis imaging

BACKGROUND

Theranostics, an emerging technique that combines therapeutic and diagnostic modalities for various diseases, holds promise to detect cancer in early stages, eradicate metastatic tumors and ultimately reduce cancer mortality.

METHODS & RESULTS

This study reports unique polymer nanoassemblies that increase fluorescence intensity upon addition of hydrophobic drugs and either increase or decrease fluorescence intensity in acidic environments, depending on nanoparticle core environment properties. Extensive spectroscopic analyses were performed to determine optimal excitation and emission wavelengths, which enabled real time measurement of drugs releasing from the nanoassemblies and ex vivo imaging of acidic liver metastatic tumors from mice.

CONCLUSION

Polymer nanoassemblies with solvato- and halo-fluorochromic properties are promising platforms to develop novel theranostic tools for the detection and treatment of metastatic tumors.

A Novel Strategy to Improve the Therapeutic Efficacy of Gemcitabine for Non-Small Cell Lung Cancer by the Tumor-Penetrating Peptide iRGD

Non-small cell lung cancer (NSCLC) is the most common type of lung cancer, comprising approximately 75–80% of all lung cancers. Gemcitabine is an approved chemotherapy drug for NSCLC. The objective of this study was to develop a novel strategy to improve the therapeutic efficacy of Gemcitabine for NSCLC by the co-administered iRGD peptide. We showed that the rates of positive expression of αvβ3, αvβ5 and NRP-1 in the A549 cell line were 68.5%, 35.3% and 94.5%, respectively. The amount of Evans Blue accumulated in the tumor of Evans Blue+iRGD group was 2.5 times that of Evans Blue group. The rates of growth inhibition of the tumors of the iRGD group, the Gemcitabine group and the Gemcitabine+iRGD group were 8%, 59.8% and 86.9%, respectively. The results of mechanism studies showed that PCNA expression in the Gemcitabine+iRGD group decreased 71.5% compared with that in Gemcitabine group. The rate of apoptosis in the Gemcitabine+iRGD group was 2.2 time that of the Gemcitabine group. Therefore, the tumor-penetrating Peptide iRGD can enhance the tumor-penetrating ability and therapeutic efficacy of Gemcitabine in the A549 xenograft. The combined application of Gemcitabine with iRGD may be a novel strategy to enhance the clinical therapeutic efficacy of Gemcitabine in patients with NSCLC.

Deoxycytidine kinase expression underpins response to gemcitabine in bladder cancer

PURPOSE

In a recent phase II clinical trial, low-dose (100 mg/m(2)) gemcitabine showed promise as a radiosensitizer in bladder cancer, but underlying mechanisms lack elucidation. Here, we investigated the mechanism of radiosensitization by low-dose gemcitabine in bladder cancer cell lines.

EXPERIMENTAL DESIGN

Four bladder cancer cell lines were screened for radiosensitization by low-dose gemcitabine using clonogenic assay, and gemcitabine-resistant RT112gem and CALgem cells created by exposure to increasing gemcitabine doses. Four key gemcitabine-regulatory genes were knocked down by transient siRNA. Nude mice carrying CALgem subcutaneous xenografts were exposed to 100 mg/kg gemcitabine ± ionizing radiation (IR) and response assessed by tumor growth delay.

RESULTS

Gemcitabine was cytotoxic in the low nanomolar range (10-40 nmol/L) in four bladder cancer cell lines and radiosensitized all four lines. Sensitizer enhancement ratios at 10% survival were: RT112 1.42, CAL29 1.55, T24 1.63, and VMCUB1 1.47. Transient siRNA knockdown of deoxycytidine kinase (dCK) significantly reduced radiosensitization by gemcitabine (P = 0.02). RT112gem and CALgem cells displayed robust decreases of dCK mRNA and protein levels; reexpression of dCK restored gemcitabine sensitivity. However, CALgem xenografts responded better to combination gemcitabine/IR than either treatment alone (P < 0.001) with dCK strongly expressed in the tumor vasculature and stroma.

CONCLUSIONS

Gemcitabine resistance in bladder cancer cell lines was associated with decreased dCK expression, but gemcitabine-resistant xenografts were responsive to combination low-dose gemcitabine/IR. We propose that dCK activity in tumor vasculature renders it gemcitabine sensitive, which is sufficient to invoke a tumor response and permit tumor cell kill in gemcitabine-resistant tumors.

In situ evaluation of gemcitabine-DNA interaction using a DNA-electrochemical biosensor

The electrochemical behaviour of the cytosine nucleoside analogue and anti-cancer drug gemcitabine (GEM) was investigated at glassy carbon electrode, using cyclic, differential pulse and square wave voltammetry, in different pH supporting electrolytes, and no electrochemical redox process was observed. The evaluation of the interaction between GEM and DNA in incubated solutions and using the DNA-electrochemical biosensor was studied. The DNA structural modifications and damage were electrochemically detected following the changes in the oxidation peaks of guanosine and adenosine residues and the occurrence of the free guanine residues electrochemical signal. The DNA-GEM interaction mechanism occurred in two sequential steps. The initial process was independent of the DNA sequence and led to the condensation/aggregation of the DNA strands, producing rigid structures, which favoured a second step, in which the guanine hydrogen atoms, participating in the C-G base pair, interacted with the GEM ribose moiety fluorine atoms.

Recent advances in the diagnosis and treatment of bladder cancer

Bladder cancer is the commonest malignancy of the urinary tract. In this review, we look at the latest developments in the diagnosis and management of this condition. Cystoscopy and urine cytology are the most important tools in the diagnosis and follow-up of bladder cancer. Various alternatives have been investigated, either to reduce the frequency of cystoscopy, or improve its sensitivity for detection of tumors. These include urine-based markers and point-of-care tests. Narrow-band imaging and photodynamic diagnosis/blue-light cystoscopy have shown promise in improving detection and reducing recurrence of bladder tumors, by improving the completion of bladder resection when compared with standard resection in white light. The majority of patients with a new diagnosis of bladder cancer have non-muscle-invasive bladder cancer, which requires adjuvant intravesical chemotherapy and/or immunotherapy. Recent developments in post-resection intravesical regimens are discussed. For patients with muscle-invasive bladder cancer, both laparoscopic radical cystectomy and robot-assisted radical cystectomy have been shown to reduce peri-operative morbidity, while being oncologically equivalent to open radical cystectomy in the medium term. Bladder-preserving strategies entail resection and chemoradiation, and in selected patients give equivalent results to surgery. The development, advantages, and disadvantages of these newer approaches are also discussed.

Toxicogenomic activity of gemcitabine in two TP53-mutated bladder cancer cell lines: special focus on cell cycle-related genes

Because of its lower toxicity and good tolerability and response, gemcitabine has been described as one of the most highly promising drugs for urinary bladder cancer therapy. Its phosphorylated active-dFdCTP metabolite can incorporate into DNA, causing replication blockage. Additionally, it is known that mutations in the TP53 gene are related to the high recurrence rate of these neoplasias. Based on these premises, we investigated the effects of gemcitabine on the expression of the cell cycle-related genes in two different TP53-mutated bladder transitional carcinoma cell lines-5637 (from a moderate-grade tumor with a TP53 allele carrying two mutations) and T24 (from an invasive tumor with a TP53 allele encoding an in-frame deletion). Cell viability and morphology analyses (phase-contrast photomicrographs), Nuclear Division Index and pathway-specific quantitative RT-PCR gene arrays were performed. Treatment with gemcitabine led to the following results: (1) a significant decrease of viable T24 cells after treatment at the highest concentration (3.12 μM) tested; (2) scattered, elongated and vacuolated 5637 and T24 cells; (3) a cytostatic effect in both cell lines; and (4) significant upregulation of the BRCA1, CCNE1, CDK2, CDK6, CDKN1A, CDKN2B, E2F4, GADD45A, MAD2L2, CCNH, SERTAD1, CDC1, and CHEK1 genes. Gemcitabine had distinct toxicogenomic effects in the bladder transitional carcinoma cell lines with two different TP53 mutations. However, independent of the type of mutation and tumor grade, gemcitabine induced cell cycle arrest; upregulation of DNA repair-related genes, G1/S transition, apoptosis and activation of transcription factors, mainly by upregulation of the CCNE1, CDKN1A and GADD45A genes.

Noxa enhances the cytotoxic effect of gemcitabine in human ovarian cancer cells

Noxa is an important proapoptotic protein in the intrinsic pathway of cell apoptosis. Experiments were carried out to investigate whether Noxa could, therefore, enhance the cytotoxic effect of gemcitabine in human ovarian cancer cell lines (A2780 and COC1). In this study, the combined treatment of Noxa and gemcitabine, in vitro, significantly inhibited the proliferation of A2780 and COC1 cells, as verified by MTT assay, Hoechst staining, and flow cytometric analysis. Moreover, the combination of Noxa and gemcitabine inhibited tumor growth and prolonged the survival of nude mice in vivo. The combined treatment also inhibited the growth of tumor xenografts through the inhibition of proliferation and the induction of apoptosis, as observed in immunohistochemical anti-PCNA staining and TdT-mediated dUTP-biotin nick-end labeling (TUNEL) assay. Our data suggest that Noxa exhibited potent proapoptotic activity against human ovarian cancer cells, and the combination of Noxa and gemcitabine showed a more significant cytotoxic effect against ovarian cancer cells in comparison with either of these agents alone. To our knowledge, we have provided the first evidence that Noxa can enhance therapeutic responses of ovarian cancer cells to gemcitabine, and that it could be potentially useful as a chemosensitizer in ovarian cancer therapy.

Contribution of tumoral and host solute carriers to clinical drug response

Members of the solute carrier family of transporters are responsible for the cellular uptake of a broad range of endogenous compounds and xenobiotics in multiple tissues. Several of these solute carriers are known to be expressed in cancer cells or cancer cell lines, and decreased cellular uptake of drugs potentially contributes to the development of resistance. As result, the expression levels of these proteins in humans have important consequences for an individual's susceptibility to certain drug-induced side effects, interactions, and treatment efficacy. In this review article, we provide an update of this rapidly emerging field, with specific emphasis on the direct contribution of solute carriers to anticancer drug uptake in tumors, the role of these carriers in regulation of anticancer drug disposition, and recent advances in attempts to evaluate these proteins as therapeutic targets.