The potential role of bortezomib in combination with chemotherapy and radiation in non-small-cell lung cancer

Targeting metabolic pathways alleviates bortezomib-induced neuropathic pain without compromising anticancer efficacy in a sex-specific manner

Introduction

Chemotherapy-induced peripheral neuropathy (CIPN) is a debilitating side effect of cancer treatment that significantly impacts patients' quality of life. This study investigated the effects of targeting metabolic pathways on bortezomib-induced neuropathic pain and tumor growth using a Lewis lung carcinoma (LLC) mouse model, while exploring potential sex differences.

Methods

Male and female C57BL/6J mice were implanted with LLC cells and treated with bortezomib alone or in combination with metformin, dichloroacetate (DCA), or oxamate. Tactile allodynia was assessed using von Frey filaments. Tumor volume and weight were measured to evaluate tumor growth.

Results

Metformin, DCA, and oxamate effectively attenuated bortezomib-induced neuropathic pain without compromising the anticancer efficacy of bortezomib in both male and female mice. The LLC model exhibited a paraneoplastic neuropathy-like phenotype. Significant sex differences were observed, with male mice exhibiting larger tumors compared to females. Oxamate was more effective in alleviating allodynia in males, while metformin and DCA showed greater efficacy in reducing tumor growth in females.

Discussion

Targeting metabolic pathways can alleviate CIPN without interfering with bortezomib's anticancer effects. The LLC model may serve as a tool for studying paraneoplastic neuropathy. Sex differences in tumor growth and response to metabolic interventions highlight the importance of considering sex as a biological variable in preclinical and clinical studies investigating cancer biology, CIPN, and potential therapeutic interventions.

Triphenylboroxine stability under low-energy-electron interactions

The high stability of triphenylboroxine under low energy electron interactions, in the energy range of 0–70 eV, supports their potential application in drug delivery, as well as in the design of technological applications.

Bortezomib induces cellular senescence in A549 lung cancer cells by stimulating telomere shortening

Bortezomib (BTZ) is a first-generation proteasome inhibitor with anti-tumor properties for multiple myeloma and mantle cell lymphoma. Increasing evidence has shown that BTZ exhibits toxic effects on diverse tumor cells, including non-small cell lung cancer (NSCLC) cells. However, the mechanism has not been fully evaluated. Here, we examined the regulatory effect of BTZ on cellular senescence, a potent tumor suppressive mechanism, in NSCLC cell lines. SA-β-gal staining assay showed that BTZ caused a significant increase in β-Gal positive A549 cells. BTZ also induced cell cycle arrest on G0/G1 phase in A549 cells. Furthermore, telomerase activity was markedly reduced in A549 cells treated with BTZ. BTZ reduced the expression levels of hTERT, and the key proteins binding to telomeric DNA, including POT1 and TIN2. It also induced the expressions of the cell cycle-associated tumor suppressors p53 and p21 in A549 cells. Moreover, hTERT overexpression abolished the effects of BTZ on A549 cells. These results show that BTZ induced cellular senescence by stimulating telomere shortening. Our results provide experimental data for the potential clinical application of BTZ in NSCLC treatment.

Additive Benefits of Radium-223 Dichloride and Bortezomib Combination in a Systemic Multiple Myeloma Mouse Model

Osteolytic bone disease is a hallmark of multiple myeloma (MM) mediated by MM cell proliferation, increased osteoclast activity, and suppressed osteoblast function. The proteasome inhibitor bortezomib targets MM cells and improves bone health in MM patients. Radium-223 dichloride (radium-223), the first targeted alpha therapy approved, specifically targets bone metastases, where it disrupts the activity of both tumor cells and tumor-supporting bone cells in mouse models of breast and prostate cancer bone metastasis. We hypothesized that radium-223 and bortezomib combination treatment would have additive effects on MM. In vitro experiments revealed that the combination treatment inhibited MM cell proliferation and demonstrated additive efficacy. In the systemic, syngeneic 5TGM1 mouse MM model, both bortezomib and radium-223 decreased the osteolytic lesion area, and their combination was more effective than either monotherapy alone. Bortezomib decreased the number of osteoclasts at the tumor-bone interface, and the combination therapy resulted in almost complete eradication of osteoclasts. Furthermore, the combination therapy improved the incorporation of radium-223 into MM-bearing bone. Importantly, the combination therapy decreased tumor burden and restored body weights in MM mice. These results suggest that the combination of radium-223 with bortezomib could constitute a novel, effective therapy for MM and, in particular, myeloma bone disease.

Bortezomib combined with lenalidomide as the first-line treatment for the rare synchronous occurrence of multiple myeloma and pulmonary adenocarcinoma: A case report

BACKGROUND

Simultaneous multiple myeloma (MM) and pulmonary adenocarcinoma is a rare occurrence, and thus, treatment is a challenge. This study reports on 1 such case of MM with concurrent lung cancer, where an accurate diagnosis was made and the patient underwent treatment for both cancers.

CASE SUMMARY

A 68-year-old man presented with 2 months of progressive lower back pain. Visualization with magnetic resonance imaging (MRI) revealed multiple collapsed vertebrae from T12 to S3, as well as an altered signal intensity at the T3 vertebra. The patient was diagnosed with MM upon examination. A chest computed tomography (CT) scan revealed a round mass in the left lower lobe of the lungs, and a CT-guided needle biopsy uncovered a moderately differentiated adenocarcinoma. There were no additional notable findings in the left lung using positron emission tomography computed tomography (PET-CT). Therefore, a diagnosis of MM with pulmonary adenocarcinoma was made. Surgery was performed to excise the lung cancer. Bortezomib was used as first-line induction therapy against both tumors and lenalidomide was used for maintenance. The patient went into complete remission. Using this combined chemotherapy, the patient has survived for over 3 years since a diagnosis was made despite relapsing twice after the first year.

CONCLUSION

This report clearly delineates the diagnosis and treatment of a rare case of synchronous MM and pulmonary adenocarcinoma, as well as depicts a potentially positive outcome for the patient. It also overviews some diagnostic and therapeutic implications for clinicians.

Role of Nrf2, HO-1 and GSH in Neuroblastoma Cell Resistance to Bortezomib

The activation of Nrf2 has been demonstrated to play a crucial role in cancer cell resistance to different anticancer therapies. The inhibition of proteasome activity has been proposed as a chemosensitizing therapy but the activation of Nrf2 could reduce its efficacy. Using the highly chemoresistant neuroblastoma cells HTLA-230, here we show that the strong reduction in proteasome activity, obtained by using low concentration of bortezomib (BTZ, 2.5 nM), fails in reducing cell viability. BTZ treatment favours the binding of Nrf2 to the ARE sequences in the promoter regions of target genes such as heme oxygenase 1 (HO-1), the modulatory subunit of γ-glutamylcysteine ligase (GCLM) and the transporter for cysteine (x-CT), enabling their transcription. GSH level is also increased after BTZ treatment. The up-regulation of Nrf2 target genes is responsible for cell resistance since HO-1 silencing and GSH depletion synergistically decrease BTZ-treated cell viability. Moreover, cell exposure to all-trans-Retinoic acid (ATRA, 3 μM) reduces the binding of Nrf2 to the ARE sequences, decreases HO-1 induction and lowers GSH level increasing the efficacy of bortezomib. These data suggest the role of Nrf2, HO-1 and GSH as molecular targets to improve the efficacy of low doses of bortezomib in the treatment of malignant neuroblastoma.

A phase I/II study of bortezomib in combination with paclitaxel, carboplatin, and concurrent thoracic radiation therapy for non-small-cell lung cancer: North Central Cancer Treatment Group (NCCTG)-N0321

INTRODUCTION

Despite the advances in radiation techniques and chemotherapy, survival with current platinum-based chemotherapy and concomitant thoracic radiation remains dismal. Bortezomib, a proteasome inhibitor, modulates apoptosis and cell cycle through disruption of protein degradation. The combination of bortezomib and carboplatin/paclitaxel and concurrent radiation in unresectable stage III non-small-cell lung cancer was evaluated in this phase I/II study.

METHODS

Patients with histologic or cytologic confirmed stage III nonmetastatic non-small-cell lung cancer who were candidates for radiation therapy were eligible. In the phase I portion, patients received escalating doses of bortezomib, paclitaxel, and carboplatin concomitantly with thoracic radiation (60 Gy/30 daily fractions) using a modified 3 + 3 design. The primary endpoint for the phase II portion was the 12-month survival rate (12MS). A one-stage design with an interim analysis yielded 81% power to detect a true 12MS of 75%, with a 0.09 level of significance if the true 12MS was 60% using a sample size of 60 patients. Secondary endpoints consisted of adverse events (AEs), overall survival, progression-free survival, and the confirmed response rate.

RESULTS

Thirty-one patients enrolled during the phase I portion of the trial, of which four cancelled before receiving treatment, leaving 27 evaluable patients. Of these 27 patients, two dose-limiting toxicities were observed, one (grade 3 pneumonitis) at dose level 1 (bortezomib at 0.5 mg/m, paclitaxel at 150 mg/m, and carboplatin at area under the curve of 5) and one (grade 4 neutropenia lasting ≥8 days) at dose level 6 (bortezomib 1.2 mg/m, paclitaxel 175 mg/m, and carboplatin at area under the curve of 6). During the phase I portion, the most common grade 3 of 4 AEs were leukopenia (44%), neutropenia (37%), dyspnea (22%), and dysphagia (11%). Dose level 6 was declared to be the recommended phase II dose (RP2D) and the phase II portion of the study opened. After the first 26 evaluable patients were enrolled to the RP2D, a per protocol interim analysis occurred. Of these 26 patients, 23 (88%) survived at least 6 months (95% confidence interval [CI], 70-98%), which was enough to continue to full accrual per study design. However, due to slow accrual, the study was stopped after 27 evaluable patients were enrolled (6-phase I RP2D; 21-phase II). Of these 27 patients, the 12MS was 73% (95% CI, 58-92%), the median overall survival was 25.0 months (95% CI, 15.6-35.8), and the median progression-free survival was 8.4 months (95% CI, 4.1-10.5). The confirmed response rate was 26% (seven of 27; 95% CI, 11-46%), consisting of four partial responses and three complete responses. Grade 3+ and grade 4+ AEs occurred in 82% and 56% of patients, respectively. One patient experienced grade 5 pneumonitis that was possibly related to the treatment. Grade 3 and 4 hematological toxicities were observed in 82% and 56% patients, respectively.

CONCLUSIONS

The addition of bortezomib to concurrent carboplatin/paclitaxel and radiation seemed to be feasible, although associated with increased hematological toxicities. A favorable median overall survival of 25 months suggests a potential benefit for this regimen.

Overview of proteasome inhibitor-based anti-cancer therapies: perspective on bortezomib and second generation proteasome inhibitors versus future generation inhibitors of ubiquitin-proteasome system

Over the past ten years, proteasome inhibition has emerged as an effective therapeutic strategy for treating multiple myeloma (MM) and some lymphomas. In 2003, Bortezomib (BTZ) became the first proteasome inhibitor approved by the U.S. Food and Drug Administration (FDA). BTZ-based therapies have become a staple for the treatment of MM at all stages of the disease. The survival rate of MM patients has improved significantly since clinical introduction of BTZ and other immunomodulatory drugs. However, BTZ has several limitations. Not all patients respond to BTZ based therapies and relapse occurs in many patients who initially responded. Solid tumors, in particular, are often resistant to BTZ. Furthermore, BTZ can induce dose-limiting peripheral neuropathy (PN). The second generation proteasome inhibitor Carfizomib (CFZ; U.S. FDA approved in August 2012) induces responses in a minority of MM patients relapsed from or refractory to BTZ. There is less PN compared to BTZ. Four other second-generation proteasome inhibitors (Ixazomib, Delanzomib, Oprozomib and Marizomib) with different pharmacologic properties and broader anticancer activities, have also shown some clinical activity in bortezomib-resistant cancers. While the mechanism of resistance to bortezomib in human cancers still remains to be fully understood, targeting the immunoproteasome, ubiquitin E3 ligases, the 19S proteasome and deubiquitinases in pre-clinical studies represents possible directions for future generation inhibitors of ubiquitin-proteasome system in the treatment of MM and other cancers.

Proteasome inhibitors block DNA repair and radiosensitize non-small cell lung cancer

Despite optimal radiation therapy (RT), chemotherapy and/or surgery, a majority of patients with locally advanced non-small cell lung cancer (NSCLC) fail treatment. To identify novel gene targets for improved tumor control, we performed whole genome RNAi screens to identify knockdowns that most reproducibly increase NSCLC cytotoxicity. These screens identified several proteasome subunits among top hits, including the topmost hit PSMA1, a component of the core 20 S proteasome. Radiation and proteasome inhibition showed synergistic effects. Proteasome inhibition resulted in an 80–90% decrease in homologous recombination (HR), a 50% decrease in expression of NF-κB-inducible HR genes BRCA1 and FANCD2, and a reduction of BRCA1, FANCD2 and RAD51 ionizing radiation-induced foci. IκBα RNAi knockdown rescued NSCLC radioresistance. Irradiation of mice with NCI-H460 xenografts after inducible PSMA1 shRNA knockdown markedly increased murine survival compared to either treatment alone. Proteasome inhibition is a promising strategy for NSCLC radiosensitization via inhibition of NF-κB-mediated expression of Fanconi Anemia/HR DNA repair genes.

Nuclear factor-kappaB (NF-kappaB) mediates a protective response in cancer cells treated with inhibitors of fatty acid synthase

The efficacy of drugs used to treat cancer can be significantly attenuated by adaptive responses of neoplastic cells to drug-induced stress. To determine how cancer cells respond to inhibition of the enzyme fatty acid synthase (FAS), we focused on NF-κB-mediated pathways, which can be activated by various cellular stresses. Treating lung cancer cells with C93, a pharmacological inhibitor of FAS, results in changes indicative of a rapid initiation of NF-κB signaling, including translocation of RelA/p65 NF-κB to the nucleus, activation of a transfected NF-κB-luciferase reporter, and increased expression of NF-κB-dependent transcripts, IL-6, IL-8, and COX-2. Verifying that these responses to C93 are specifically related to inhibition of FAS, we confirmed that levels of these same transcripts increase in response to siRNA targeting FAS. Inhibiting this NF-κB response (either by transfecting a mutant IκBα or treating with bortezomib) resulted in increased cell killing by C93, indicating that the NF-κB response is protective in this setting. Because inhibiting FAS leads to accumulation of intermediate metabolites of fatty acid biosynthesis, we then questioned whether protein kinase C (PKC) is involved in this response to metabolic stress. Immunofluorescence microscopy revealed that C93 treatment results in cellular translocation of PKCα and PKCβ isoforms and increased PKCα-dependent phosphorylation of the IκBα subunit of NF-κB. Furthermore, inhibiting PKC activity with RO-31-8220 or PKCα isoform-specific siRNA attenuates C93-induced IκBα phosphorylation and NF-κB activation and also potentiates C93-induced cell killing. These results suggest a link between PKC and NF-κB in protecting cancer cells from metabolic stress induced by inhibiting FAS.

Bortezomib as the first proteasome inhibitor anticancer drug: current status and future perspectives

Targeting the ubiquitin-proteasome pathway has emerged as a rational approach in the treatment of human cancer. Based on positive preclinical and clinical studies, bortezomib was subsequently approved for the clinical use as a front-line treatment for newly diagnosed multiple myeloma patients and for the treatment of relapsed/refractory multiple myeloma and mantle cell lymphoma, for which this drug has become the staple of treatment. The approval of bortezomib by the US Food and Drug Administration (FDA) represented a significant milestone as the first proteasome inhibitor to be implemented in the treatment of malignant disease. Bortezomib has shown a positive clinical benefit either alone or as a part of combination therapy to induce chemo-/radio-sensitization or overcome drug resistance. One of the major mechanisms of bortezomib associated with its anticancer activity is through upregulation of NOXA, which is a proapoptotic protein, and NOXA may interact with the anti-apoptotic proteins of Bcl-2 subfamily Bcl-X(L) and Bcl-2, and result in apoptotic cell death in malignant cells. Another important mechanism of bortezomib is through suppression of the NF-κB signaling pathway resulting in the down-regulation of its anti-apoptotic target genes. Although the majority of success achieved with bortezomib has been in hematological malignancies, its effect toward solid tumors has been less than encouraging. Additionally, the widespread clinical use of bortezomib continues to be hampered by the appearance of dose-limiting toxicities, drug-resistance and interference by some natural compounds. These findings could help guide physicians in refining the clinical use of bortezomib, and encourage basic scientists to generate next generation proteasome inhibitors that broaden the spectrum of efficacy and produce a more durable clinical response in cancer patients. Other desirable applications for the use of proteasome inhibitors include the development of inhibitors against specific E3 ligases, which act at an early step in the ubiquitin-proteasome pathway, and the discovery of less toxic and novel proteasome inhibitors from natural products and traditional medicines, which may provide more viable drug candidates for cancer chemoprevention and the treatment of cancer patients in the future.

Phase I trial of carboplatin/paclitaxel/bortezomib and concurrent radiotherapy followed by surgical resection in Stage III non-small cell lung cancer

INTRODUCTION

Despite advances in Stage III NSCLC, the mortality from the disease remains >70%. Disease recurrence can occur both locally and systemically. Trimodality therapy may improve outcome by maximizing local control. The purpose of this study was to perform a phase I trial of bortezomib (PS-341, Velcade) in addition to chemotherapy with carboplatin AUC=2 and paclitaxel 50mg/m(2) and concurrent radiotherapy (61 Gy) as induction treatment in a trimodality approach.

METHODS

Patients with pathologically documented Stage III a (N2) or selected IIIb (N3) disease were eligible. Bortezomib was administered on days 1, 4, 15, 18 during the 6-week induction chemoradiotherapy. Cohorts of three patients were entered and observed for toxicity during chemoradiotherapy and for 2 weeks afterwards. Surgical resection was attempted in the patients who had mediastinal sterilization. All patients were to receive consolidation chemotherapy with carboplatin AUC=6 and paclitaxel 200mg/m(2).

RESULTS

Twelve patients in three cohorts were enrolled. The addition of bortezomib was well tolerated, with no unexpected toxicities during the induction phase. However, there were three postoperative deaths (two pneumonitis and one from failure of the bronchopulmonary flap). The trial was halted as a consequence of these toxicities.

CONCLUSIONS

While this approach was well tolerated in terms of acute toxicity, the apparently delayed toxicity was severe and unpredictable. It does not appear that bortezomib can be safely administered as part of preoperative chemoradiotherapy for lung cancer. However, there was a high incidence of complete pathologic response and cautious exploration of this agent in the non-operative setting is appropriate.

Phase II study of the proteasome inhibitor bortezomib (PS-341, Velcade) in chemotherapy-naïve patients with advanced stage non-small cell lung cancer (NSCLC)

The primary objective of this study was to determine the objective response rate of bortezomib as a first-line therapy in patients advanced stage NSCLC. Advanced/metastatic NSCLC patients with measurable disease, adequate organ function, ECOG performance status of 0-2, and no prior chemotherapy for metastatic disease were eligible. Patients received intravenously bolus bortezomib 1.3mg/m(2)/day on days 1, 4, 8 and 11 every 21 days for a maximum of 8 cycles, or until disease progression, or unacceptable toxicity. Tumor response was evaluated after every 2 cycles of therapy. This single-arm phase II study employed the Simon's two-stage design. The study was terminated in the first stage after 14 patients enrolled at 4 institutions. No objective response was observed. Three patients (21%) had stable disease and received 8, 6 and 4 cycles of treatment; the duration of stable disease was 11.5, 4.2 and 3.4 months, respectively. Median time to progression was 1.3 months (95% CI, 0.6-3.0 months); median overall survival (OS) was 9.9 months (95% CI, 2.2-27.0 months). Twelve patients received at least one dose of bortezomib. There were no grade 4 toxicities or treatment related deaths. Grade 3 toxicities included fatigue (N=1, 8%), deep vein thrombosis (N=1, 8%) and thrombocytopenia (N=1, 8%). Although well tolerated, bortezomib monotherapy is not active in this cohort of chemotherapy-naïve, metastatic NSCLC.