Randomized phase II study of bortezomib alone and bortezomib in combination with docetaxel in previously treated advanced non-small-cell lung cancer

Oncogenic Mutant p53 Sensitizes Non-Small Cell Lung Cancer Cells to Proteasome Inhibition via Oxidative Stress-Dependent Induction of Mitochondrial Apoptosis

SIGNIFICANCE

NSCLC is the leading cause of cancer death due, in part, to a lack of active therapies in advanced disease. We demonstrate that combination therapy with a proteasome inhibitor, BH3-mimetic, and chemotherapy is an active precision therapy in NSCLC cells and tumors expressing Onc-p53 alleles.

Anti-BCMA-engineered exosomes for bortezomib-targeted delivery in multiple myeloma

ABSTRACT

Exosomes have emerged as promising vehicles for delivering therapeutic cargoes to specific cells or tissues, owing to their superior biocompatibility, reduced immunogenicity, and enhanced targeting capabilities compared with conventional drug delivery systems. In this study, we developed a delivery platform using exosomes derived from monocytes, specifically designed for targeted delivery of bortezomib (Btz) to multiple myeloma (MM) cells. Our approach involved the genetic modification of monocytes to express antibodies targeting B-cell maturation antigen (anti-BCMA), because BCMA selectively expresses on myeloma cells. This modified anti-BCMA was then efficiently incorporated into the monocyte-derived exosomes. These adapted exosomes effectively encapsulated Btz, leading to enhanced drug accessibility within MM cells and sustained intracellular accumulation over an extended period. Remarkably, our results demonstrated that anti-BCMA-modified exosome-loaded Btz (anti-BCMA-Exo-Btz) outperformed free Btz in vitro, exhibiting a more potent myeloma-suppressive effect. In orthotopic MM xenograft models, anti-BCMA-Exo-Btz exhibited a significant antitumor effect compared with free Btz. Furthermore, it demonstrated remarkable specificity in targeting Btz to myeloma cells in vivo. Importantly, we observed no significant histological damage in mice treated with anti-BCMA-Exo-Btz and a slight effect on peripheral blood mononuclear cells. In addition, our study highlighted the multifunctional potential of monocyte exosomes, which induced cell apoptosis, mediated immune responses, and enhanced the osteogenic potential of mesenchymal stromal cells. In conclusion, our study suggests that exosomes modified with targeting ligands hold therapeutic promise for delivering Btz to myelomas, offering substantial potential for clinical applications.

Dual network analysis of transcriptome data for discovery of new therapeutic targets in non-small cell lung cancer

The drug therapy for non-small cell lung cancer (NSCLC) have always been issues of poisonous side effect, acquired drug resistance and narrow applicable population. In this study, we built a novel network analysis method (difference- correlation- enrichment- causality- node), which was based on the difference analysis, Spearman correlation network analysis, biological function analysis and Bayesian causality network analysis to discover new therapeutic target of NSCLC in the sequencing data of BEAS-2B and 7 NSCLC cell lines. Our results showed that, as a proteasome subunit coding gene in the central of cell cycle network, PSMD2 was associated with prognosis and was an independent prognostic factor for NSCLC patients. Knockout of PSMD2 inhibited the proliferation of NSCLC cells by inducing cell cycle arrest, and exhibited marked increase of cell cycle blocking protein p21, p27 and decrease of cell cycle driven protein CDK4, CDK6, CCND1 and CCNE1. IPA and molecular docking suggested bortezomib has stronger affinity to PSMD2 compared with reported targets PSMB1 and PSMB5. In vitro and In vivo experiments demonstrated the inhibitory effect of bortezomib in NSCLC with different driven mutations or with tyrosine kinase inhibitors resistance. Taken together, bortezomib could target PSMD2, PSMB1 and PSMB5 to inhibit the proteasome degradation of cell cycle check points, to block cell proliferation of NSCLC, which was potential optional drug for NSCLC patients.

Proteasome inhibitors in the treatment of nonsmall cell lung cancer: A systematic review of clinical evidence

Background and Aims

Nonsmall cell lung cancer accounts for over 85% of lung cancer incidences worldwide, and often has a poor prognosis. Proteasome inhibitors, such as bortezomib, have previously demonstrated evidence in preclinical and clinical models in the treatment of NSCLC both alone and as part of chemotherapeutic regimens.

Methods

Five databases were searched from inception to February 2023 to identify published clinical trial data and ongoing clinical trials on the use of proteasome inhibitors in treatment of NSCLC with a comprehensive search strategy.

Results

This review examines the clinical evidence from 21 completed and published phase I and II trials studying the use of bortezomib monotherapy and combination therapy in the treatment of NSCLC. Bortezomib/docetaxel combination resulted in longer median time-to-progression (TTP), median duration of response, median duration of disease control and median progression-free survival (PFS) than bortezomib monotherapy, with concurrent administration having greater 6-month PFS and median overall survival (OS) than sequential administration. Bortezomib/vorinostat with chemotherapy was well tolerated and effective. Bortezomib/gemcitabine/carboplatin, bortezomib/bevacizumab/carboplatin and bortezomib/paclitaxel/carboplatin combinations showed promising results and were of further investigational value.

Conclusion

Bortezomib showed some clinical promise in combination therapy but not monotherapy. It also demonstrated a manageable side effect profile. Combination regimens are of further investigation value in Phase II trials.

Modulation of the ubiquitin-proteasome system by phytochemicals: Therapeutic implications in malignancies with an emphasis on brain tumors

Regarding the multimechanistic nature of cancers, current chemo- or radiotherapies often fail to eradicate disease pathology, and frequent relapses or resistance to therapies occur. Brain malignancies, particularly glioblastomas, are difficult-to-treat cancers due to their highly malignant and multidimensional biology. Unfortunately, patients suffering from malignant tumors often experience poor prognoses and short survival periods. Thus far, significant efforts have been conducted to discover novel and more effective modalities. To that end, modulation of the ubiquitin-proteasome system (UPS) has attracted tremendous interest since it affects the homeostasis of proteins critically engaged in various cell functions, for example, cell metabolism, survival, proliferation, and differentiation. With their safe and multimodal actions, phytochemicals are among the promising therapeutic tools capable of turning the operation of various UPS elements. The present review, along with an updated outline of the role of UPS dysregulation in multiple cancers, provided a detailed discussion on the impact of phytochemicals on the UPS function in malignancies, especially brain tumors.

Commonly prescribed medications associated with alopecia

BACKGROUND

The diagnosis and treatment of medication-associated alopecia often challenges patients and physicians. While numerous studies on the topic exist, limited information on the strength and magnitude of these studies exists.

OBJECTIVES

We investigated the most commonly prescribed medications with high levels of evidence to support associations with alopecia.

METHODS

A list of most commonly prescribed medications was compiled using the "Top 100 Prescriptions, Sales" (Intercontinental Marketing Services) and "Top 200 Names Searched" (RxList.com). PubMed, Embase, and Web of Science were searched for "generic drug name" AND "alopecia" and "generic drug name" AND "hair loss." Two reviewers independently reviewed articles for drug, study type and level of evidence, and number of alopecia cases.

RESULTS

A total of 192 unique drugs were investigated, with 110 yielding positive search results. Of these, 13 were associated with alopecia in studies with strong levels of evidence (adalimumab, infliximab, budesonide, interferon β-1α, tacrolimus, enoxaparin, zoster vaccine, lamotrigine, docetaxel, capecitabine, erlotinib, imatinib, and bortezomib).

LIMITATIONS

Only full-length articles available in the English language were included. The methodology used relied on lists of drugs based on their sales rather than number of prescriptions, which likely overrepresented expensive drugs.

CONCLUSIONS

Few studies with high levels of evidence have been conducted on the topic of medication-associated alopecia. The mechanisms of hair loss must be further identified to provide effective management.

α-Tocotrienol and Redox-Silent Analogs of Vitamin E Enhances Bortezomib Sensitivity in Solid Cancer Cells through Modulation of NFE2L1

Proteasome inhibitors (PIs) have emerged as an attractive novel cancer therapy. However, most solid cancers are seemingly resistant to PIs. The activation of transcription factor Nuclear factor erythroid 2 related factor-1 (NFE2L1) has been characterized as a potential resistance response to protect and restore proteasome activity in cancer cells. In this study, we demonstrated that α-Tocotrienol (T3) and redox-silent analogs of vitamin E (TOS, T3E) enhanced the sensitivity of bortezomib (BTZ), a proteasome inhibitor, in solid cancers through modulation of NFE2L1. In BTZ treatment, all of T3, TOS, and T3E inhibited an increase in the protein levels of NFE2L1, the expression levels of proteasome-related proteins, as well as the recovery of proteasome activity. Moreover, the combination of one of T3, TOS, or T3E and BTZ induced a significant decrease in cell viability in solid cancer cell lines. These findings suggested that the inactivation of NFE2L1 by T3, TOS, and T3E is essential to potentiate the cytotoxic effect of the proteasome inhibitor, BTZ, in solid cancers.

The treatment of advanced non-small cell lung cancer harboring KRAS mutation: a new class of drugs for an old target-a narrative review

Background and Objective

The genetic nature of cancer provides the rationale to support the need for molecular diagnosis and patient selection for individualised antineoplastic treatments that are the best in both tolerability and efficacy for each cancer patient, including non-small cell lung cancer (NSCLC) patients. Kirsten rat sarcoma viral oncogene homolog (KRAS) mutations represent the prevalent oncogenic driver in NSCLC, being detected in roughly one-third of cases and KRAS G12C is the most frequent mutation found in approximately 13% of patients.

Methods

This paper gives an overview of the numerous scientific efforts in recent decades aimed at KRAS inhibition.

Key Content and Findings

Sotorasib is the first approved KRAS G12C inhibitor that has been shown to provide a durable clinical benefit in patients with pre-treated NSCLC with KRAS G12C mutation. Together with the development of new targeted drugs, the development of strategies to control resistance mechanisms is one of the major drivers of research that is exploring the use of KRAS inhibitors not only alone, but also in combination with other targeted therapies, chemotherapy and immunotherapy.

Conclusions

This review will describe the major therapeutic developments in KRAS mutation-dependent NSCLC and will analyse future perspectives to maximise benefits for this group of patients.

Progress on the Application of Bortezomib and Bortezomib-Based Nanoformulations

Bortezomib (BTZ) is the first proteasome inhibitor approved by the Food and Drug Administration. It can bind to the amino acid residues of the 26S proteasome, thereby causing the death of tumor cells. BTZ plays an irreplaceable role in the treatment of mantle cell lymphoma and multiple myeloma. Moreover, its use in the treatment of other hematological cancers and solid tumors has been investigated in numerous clinical trials and preclinical studies. Nevertheless, the applications of BTZ are limited due to its insufficient specificity, poor permeability, and low bioavailability. Therefore, in recent years, different BTZ-based drug delivery systems have been evaluated. In this review, we firstly discussed the functions of proteasome inhibitors and their mechanisms of action. Secondly, the properties of BTZ, as well as recent advances in both clinical and preclinical research, were reviewed. Finally, progress in research regarding BTZ-based nanoformulations was summarized.

A Personalized Therapeutics Approach Using an In Silico Drosophila Patient Model Reveals Optimal Chemo- and Targeted Therapy Combinations for Colorectal Cancer

In silico models of biomolecular regulation in cancer, annotated with patient-specific gene expression data, can aid in the development of novel personalized cancer therapeutic strategies. Drosophila melanogaster is a well-established animal model that is increasingly being employed to evaluate such preclinical personalized cancer therapies. Here, we report five Boolean network models of biomolecular regulation in cells lining the Drosophila midgut epithelium and annotate them with colorectal cancer patient-specific mutation data to develop an in silico Drosophila Patient Model (DPM). We employed cell-type-specific RNA-seq gene expression data from the FlyGut-seq database to annotate and then validate these networks. Next, we developed three literature-based colorectal cancer case studies to evaluate cell fate outcomes from the model. Results obtained from analyses of the proposed DPM help: (i) elucidate cell fate evolution in colorectal tumorigenesis, (ii) validate cytotoxicity of nine FDA-approved CRC drugs, and (iii) devise optimal personalized treatment combinations. The personalized network models helped identify synergistic combinations of paclitaxel-regorafenib, paclitaxel-bortezomib, docetaxel-bortezomib, and paclitaxel-imatinib for treating different colorectal cancer patients. Follow-on therapeutic screening of six colorectal cancer patients from cBioPortal using this drug combination demonstrated a 100% increase in apoptosis and a 100% decrease in proliferation. In conclusion, this work outlines a novel roadmap for decoding colorectal tumorigenesis along with the development of personalized combinatorial therapeutics for preclinical translational studies.

Pathogenesis and therapeutic strategy in platinum resistance lung cancer

Platinum compounds (cisplatin and carboplatin) represent the most active anticancer agents in clinical use both of lung cancer in mono-and combination therapies. However, platinum resistance limits its clinical application. It is necessary to understand the molecular mechanism of platinum resistance, identify predictive markers, and develop newer, more effective and less toxic agents to treat platinum resistance in lung cancer. Here, it summarizes the main molecular mechanisms associated with platinum resistance in lung cancer and the development of new approaches to tackle this clinically relevant problem. Moreover, it could lead to the development of more effective treatment for refractory lung cancer in future.

KRAS-Mutant Non-Small Cell Lung Cancer: An Emerging Promisingly Treatable Subgroup

Lung cancer, the leading cause of cancer-related deaths worldwide, can be classified into small cell lung cancer and non-small cell lung cancer (NSCLC). NSCLC is the most common histological type, accounting for 85% of all lung cancers. Kirsten rat sarcoma viral oncogene (KRAS) mutations, common in NSCLC, are associated with poor prognosis, likely due to poor responses to most systemic therapies and lack of targeted drugs. The latest published clinical trial data on new small-molecule KRAS G12C inhibitors, AMG510 and MRTX849, indicate that these molecules may potentially help treat KRAS-mutant NSCLC. Simultaneously, within the immuno-therapeutic process, immune efficacy has been observed in those patients who have KRAS mutations. In this article, the pathogenesis, treatment status, progress of immunotherapy, and targeted therapy of KRAS-mutant NSCLC are reviewed.

Proteasome Inhibition Overcomes ALK-TKI Resistance in ALK-Rearranged/TP53-Mutant NSCLC via Noxa Expression

PURPOSE

In ALK-rearranged non-small cell lung cancer (NSCLC), impacts of concomitant genetic alterations on targeted therapies with ALK-tyrosine kinase inhibitors (ALK-TKI) are not yet well understood. Here, we investigated genetic alterations related to ALK-TKI resistance using clinico-genomic data and explored effective therapies to overcome the resistance in preclinical models through the identification of underlying molecular mechanisms.

EXPERIMENTAL DESIGN

We used integrated clinical and next-generation sequencing data generated in a nationwide lung cancer genome screening project (LC-SCRUM-Japan). ALK-rearranged NSCLC cell lines expressing wild-type or mutant TP53 were used to evaluate cellular apoptosis induced by ALK-TKIs.

RESULTS

In 90 patients with ALK-rearranged NSCLC who were treated with a selective ALK-TKI, alectinib, TP53 comutated patients showed significantly worse progression-free survival (PFS) than TP53 wild-type patients [median PFS, 11.7 months (95% confidence interval, CI, 6.3-not reached, NR) vs. NR (23.6-NR); P = 0.0008; HR, 0.33 (95% CI, 0.17-0.65)]. ALK-rearranged NSCLC cell lines that lost p53 function were resistant to alectinib-induced apoptosis, but a proteasome inhibitior, ixazomib, markedly induced apoptosis in the alectinib-treated cells by increasing the expression of a proapoptotic protein, Noxa, which bound to an antiapoptotic protein, Mcl-1. In subcutaneous tumor models, combination of ixazomib and alectinib prominently induced tumor regression and apoptosis even though the tumors were generated from ALK-rearranged NSCLC cells with nonfunctional p53.

CONCLUSIONS

These clinical and preclinical results indicate concomitant TP53 mutations reduce the efficacy of alectinib for ALK-rearranged NSCLC and the combined use of a proteasome inhibitor with alectinib is a promising therapy for ALK-rearranged/TP53-mutated NSCLC.

Expression of the immunoproteasome subunit β5i in non-small cell lung carcinomas

AIM

The immunoproteasome is a specific proteasome isoform whose proteolytic activity enhances the generation of antigenic peptides to be presented by major histocompatibility complex class I molecules to CD8⁺ T cells. Physiologically, it is expressed abundantly in immune cells and is induced in somatic cells by cytokines, especially interferon-γ. Recently, variable expression of immunoproteasomes has been demonstrated in different types of cancers. However, the clinical significance of immunoproteasome expression in malignant tumours is poorly understood. In this study, we performed clinicopathological evaluation of immunoproteasome subunit β5i in non-small cell lung carcinomas (NSCLCs).

METHODS

Tumour tissues were collected from 155 patients with NSCLCs, and immunohistochemical analysis for β5i was performed in relation to the prognosis of patients.

RESULTS

High expression of β5i was found in about 20% of all NSCLCs and was found significantly more frequently (40%) in the adenocarcinoma subset. High expression of β5i was associated with a better 5-year relative survival rate in patients with pStage I to II adenocarcinoma and was also a significant and independent favourable prognostic factor in adenocarcinoma patients. In addition, when we performed in vitro analysis using NSCLC cell lines, combined treatment with the immunoproteasome-specific inhibitor ONX0914 and the proteasome inhibitor MG132 enhanced cell death in β5i-expressing NSCLC cell lines.

CONCLUSION

The expression of immunoproteasome can be explored as both a prognostic factor and a potential therapeutic target in NSCLCs. Since immunoproteasomes have crucial role in the antigen presentation, further studies may help to provide essential knowledge for therapeutic strategies in anticancer immunotherapy.

Harnessing the vulnerabilities of p53 mutants in lung cancer - Focusing on the proteasome: a new trick for an old foe?

Gain-of-function (GOF) p53 mutations occur commonly in human cancer and lead to both loss of p53 tumor suppressor function and acquisition of aggressive cancer phenotypes. The oncogenicity of GOF mutant p53 is highly related to its abnormal protein stability relative to wild type p53, and overall stoichiometric excess. We provide an overview of the mechanisms of dysfunction and abnormal stability of GOF p53 specifically in lung cancer, the leading cause of cancer-related mortality, where, depending on histologic subtype, 33-90% of tumors exhibit GOF p53 mutations. As a distinguishing feature and oncogenic mechanism in lung and many other cancers, GOF p53 represents an appealing and cancer-specific therapeutic target. We review preclinical evidence demonstrating paradoxical depletion of GOF p53 by proteasome inhibitors, as well as preclinical and clinical studies of proteasome inhibition in lung cancer. Finally, we provide a rationale for a reexamination of proteasome inhibition in lung cancer, focusing on tumors expressing GOF p53 alleles.

Proteasome Inhibitor-Induced IκB/NF-κB Activation is Mediated by Nrf2-Dependent Light Chain 3B Induction in Lung Cancer Cells

IκB, a cytoplasmic inhibitor of nuclear factor-κB (NF-κB), is reportedly degraded via the proteasome. However, we recently found that long-term incubation with proteasome inhibitors (PIs) such as PS-341 or MG132 induces IκBα degradation via an alternative pathway, lysosome, which results in NF-κB activation and confers resistance to PI-induced lung cancer cell death. To enhance the anti-cancer efficacy of PIs, elucidation of the regulatory mechanism of PI-induced IκBα degradation is necessary. Here, we demonstrated that PI upregulates nuclear factor (erythroid-derived 2)-like 2 (Nrf2) via both de novo protein synthesis and Kelch-like ECH-associated protein 1 (KEAP1) degradation, which is responsible for IκBα degradation via macroautophagy activation. PIs increased the protein level of light chain 3B (LC3B, macroautophagy marker), but not lysosome-associated membrane protein 2a (Lamp2a, the receptor for chaperone-mediated autophagy) in NCI-H157 and A549 lung cancer cells. Pretreatment with macroautophagy inhibitor or knock-down of LC3B blocked PI-induced IκBα degradation. PIs up-regulated Nrf2 by increasing its transcription and mediating degradation of KEAP1 (cytoplasmic inhibitor of Nrf2). Overexpression of dominant-negative Nrf2, which lacks an N-terminal transactivating domain, or knock-down of Nrf2 suppressed PI-induced LC3B protein expression and subsequent IκBα degradation. Thus, blocking of the Nrf2 pathway enhanced PI-induced cell death. These findings suggest that Nrf2-driven induction of LC3B plays an essential role in PI-induced activation of the IκB/NF-κB pathway, which attenuates the anti-tumor efficacy of PIs.

Sorafenib and Carfilzomib Synergistically Inhibit the Proliferation, Survival, and Metastasis of Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is one of the most common and deadly human cancers. The 5-year survival rate is very low. Unfortunately, there are few efficacious therapeutic options. Until recently, Sorafenib has been the only available systemic drug for advanced HCC. However, it has very limited survival benefits, and new therapies are urgently needed. In this study, we investigated the anti-HCC activity of carfilzomib, a second-generation, irreversible proteasome inhibitor, as a single agent and in combination with sorafenib. In vitro, we found that carfilzomib has moderate anticancer activity toward liver cancer cells, but strongly enhances the ability of sorafenib to suppress HCC cell growth, proliferation, migration, invasion, and survival. Remarkably, the drug combination exhibits even more potent antitumor activity when tested in animal tumor models. Mechanistically, the combined treatment activates caspase-dependent and endoplasmic reticulum stress/CHOP-mediated apoptotic pathways, and suppresses epithelial-mesenchymal transition. In conclusion, our results demonstrate that the combination of carfilzomib and sorafenib has synergistic antitumor activities against HCC, providing a potential therapeutic strategy to improve the mortality and morbidity of HCC patients.

Docetaxel increases the risk of severe infections in the treatment of non-small cell lung cancer: a meta-analysis

The purpose of this study was to determine whether docetaxel increases the risk of severe infections in patients with non-small cell lung cancer. A thorough literature search of the PubMed, EMBASE and Cochrane Central Register of Controlled Trials databases was performed (up to February 28, 2017) without any language restrictions. In addition, we searched the www.clinicaltrials.gov website and checked each reference listed in the included studies, relevant reviews and guidelines. We also included randomized controlled trials that reported severe infections in patients with non-small cell lung cancer who were administered docetaxel. A meta- analysis was conducted using relative risk and random effects models in Stata 14.0 software. Sensitivity analysis and meta-regression were performed using Stata 14.0 software. We identified 354 records from the initial search, and this systematic review ultimately included 43 trials with 12,447 participants. The results of our meta- analysis showed that docetaxel increased the risk of severe infections [relative risk: 2.10, 95% confidence interval: 1.51-2.93, I² = 69.6%, P = 0.000]. Meta-regression analysis indicated that the type of intervention was a major source of heterogeneity. Our systematic review and meta-analysis suggest that docetaxel is associated with the risk of severe infections.

Positioning of proteasome inhibitors in therapy of solid malignancies

Targeting of the protein degradation pathway, in particular, the ubiquitin-proteasome system, has emerged as an attractive novel cancer chemotherapeutic modality. Although proteasome inhibitors have been most successfully applied in the treatment of hematological malignancies, they also received continuing interest for the treatment of solid tumors. In this review, we summarize the current positioning of proteasome inhibitors in the treatment of common solid malignancies (e.g., lung, colon, pancreas, breast, and head and neck cancer), addressing topics of their mechanism(s) of action, predictive factors and molecular mechanisms of resistance.

Synergistic effects of combining proteasome inhibitors with chemotherapeutic drugs in lung cancer cells

Background

The prognosis for patients with disseminated lung cancer is poor and current treatments have limited survival benefit as resistance often occurs, and is often associated with significant toxicity. A possible strategy to improve treatment and evade chemoresistance may be to find new combinations of drugs. The aim of this study was to analyze the potential of combining proteasome inhibitors (PIs) with chemotherapeutic drugs used in the routine treatment for lung cancer patients.

Results

The median-effect method was applied to the Fluorometric Microculture Cytotoxicity Assay (FMCA) to evaluate effects of combining two different PIs (bortezomib and b-AP15) with clinically used chemotherapeutic drugs representing different mechanisms of action (cisplatin, gefitinib, gemcitabine and vinorelbine) in two lung cancer cell lines (one sensitive and one resistant). Proteasome inhibition in combination with cisplatin, gemcitabine or vinorelbine had synergistic effects in at least one of the tested cell lines. Furthermore, the effect of gefitinib appeared strongly potentiated by the PI in the least resistant lung cancer cell line, although the level of synergy could not be determined with the median-effect method.

Conclusions

Combining PIs with cisplatin, gefitinib, gemcitabine or vinorelbine show potential as new combination chemotherapy for the treatment of lung cancer.

Electronic supplementary material

The online version of this article (10.1186/s13104-017-2842-z) contains supplementary material, which is available to authorized users.

Leucovorin Enhances the Anti-cancer Effect of Bortezomib in Colorectal Cancer Cells

Colorectal cancer is a major cancer type worldwide. 5-fluorouracil, often given with leucovorin, is the most commonly used drug in colorectal cancer chemotherapy, yet development of drug resistance to 5-fluorouracil in colorectal cancer cells is the primary cause of chemotherapy failure. Most patients receiving intravenous 5-fluorouracil develop side effects. Leucovorin, due to its vitamin-like profile, has few side-effects. Drug repurposing is the application of approved drugs to treat new indications. In this study, we performed a novel drug-repurposing screening to identify Food and Drug Administration-approved chemotherapeutic compounds possessing synergistic activity with leucovorin against colorectal cancer cells. We found that the combination of bortezomib and leucovorin enhanced caspase activation and increased apoptosis in colorectal cancer cells better than either agent alone. Further, the synergistic induction of apoptosis and inhibition of tumor growth were also observed in mouse colorectal cancer xenografts. These data support leucovorin enhances the anti-cancer effect of bortezomib and present this novel combinatorial treatment against colorectal cancer.

Bortezomib alters sour taste sensitivity in mice

Chemotherapy-induced taste disorder is one of the critical issues in cancer therapy. Bortezomib, a proteasome inhibitor, is a key agent in multiple myeloma therapy, but it induces a taste disorder. In this study, we investigated the characteristics of bortezomib-induced taste disorder and the underlying mechanism in mice. Among the five basic tastes, the sour taste sensitivity of mice was significantly increased by bortezomib administration. In bortezomib-administered mice, protein expression of PKD2L1 was increased. The increased sour taste sensitivity induced by bortezomib returned to the control level on cessation of its administration. These results suggest that an increase in protein expression of PKD2L1 enhances the sour taste sensitivity in bortezomib-administered mice, and this alteration is reversed on cessation of its administration.

Neutrophil-Derived IL-1β Impairs the Efficacy of NF-κB Inhibitors against Lung Cancer

Although epithelial NF-κB signaling is important for lung carcinogenesis, NF-κB inhibitors are ineffective for cancer treatment. To explain this paradox, we studied mice with genetic deletion of IKKβ in myeloid cells and found enhanced tumorigenesis in Kras(G12D) and urethane models of lung cancer. Myeloid-specific inhibition of NF-κB augmented pro-IL-1β processing by cathepsin G in neutrophils, leading to increased IL-1β and enhanced epithelial cell proliferation. Combined treatment with bortezomib, a proteasome inhibitor that blocks NF-κB activation, and IL-1 receptor antagonist reduced tumor formation and growth in vivo. In lung cancer patients, plasma IL-1β levels correlated with poor prognosis, and IL-1β increased following bortezomib treatment. Together, our studies elucidate an important role for neutrophils and IL-1β in lung carcinogenesis and resistance to NF-κB inhibitors.

A phase II, open-label trial of bortezomib (VELCADE(®)) in combination with gemcitabine and cisplatin in patients with locally advanced or metastatic non-small cell lung cancer

BACKGROUND

Bortezomib is a selective reversible proteasome inhibitor with proapoptotic effects. Preclinical and phase I clinical data suggest activity of bortezomib in NSCLC, either as monotherapy or in combination with chemotherapeutic agents including gemcitabine and cisplatin.

METHODS

Chemotherapy-naïve patients with inoperable stage IIIB or IV NSCLC were administered bortezomib 1 mg/m(2) i.v. on days 1 and 8, and starting on day 21 (cycle 2), bortezomib (days 1 and 8) in combination with gemcitabine 1000 mg/m(2), (days 1 and 8), and cisplatin 70 mg/m(2) (day 1) in cycles of 21 days. Up to 8 cycles of combination therapy could be administered; single-agent bortezomib was continued until disease progression or unacceptable toxicity.

RESULTS

Fifty-three patients [median age 66 years; 79.2 % male; 96.2 % stage IV; performance status (ECOG) 0/1 73.6/26.4 %; adenocarcinoma 45.3 %, squamous cell carcinoma 41.5 %] were enrolled. All patients were evaluable for toxicity and 43 for efficacy. Grade 3-4 hematologic toxicity consisted of neutropenia (22.6 %) and thrombocytopenia (17 %). Grade 2-4 non-hematologic adverse events were fever (9.4 %), fatigue (20.8 %), infection (18.9 %), and dyspnea (15.1 %). There was no >grade 2 neurotoxicity. Febrile neutropenia occurred in two (1.9 %) patients, and there were three possibly treatment-related deaths (5.4 %). In the intention-to-treat population, the objective response rate was 17 % (95 % CI 6.9-27.1 %). No difference in response rate was observed for squamous versus other histology (18.2 vs. 16.1 %, p = 0.845). The median progression-free survival was 2.5 months, the median overall survival 10.6 months and the 1-year survival rate 38.1 %.

CONCLUSION

The incorporation of bortezomib into the gemcitabine/cisplatin regimen, in the dose and schedule used in this study, could not improve the efficacy of the chemotherapy regimen and has not to be further investigated.

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.

Alopecia in patients treated with molecularly targeted anticancer therapies

BACKGROUND

The introduction of molecularly targeted anticancer therapies presents new challenges, among which dermatologic adverse events are noteworthy. Alopecia in particular is frequently reported, but the true incidence is not known.

PATIENTS AND METHODS

We sought to ascertain the incidence and risk of developing alopecia during treatment with approved inhibitors of oncogenic pathways and molecules [anaplastic lymphoma kinase, breakpoint cluster region-abelson, B-rapidly accelerated fibrosarcoma, Bruton's tyrosine kinase, cytotoxic T-lymphocyte antigen-4, epidermal growth factor receptor, human epidermal growth factor receptor-2, Janus kinase, MAPK/ERK (extracellular signal-regulated kinase) Kinase, mammalian target of rapamycin, smoothened, vascular endothelial growth factor, vascular endothelial growth factor receptor, platelet derived growth factor receptor; proteasomes; CD20, CD30, CD52]. Electronic database (PubMed, Web of Science) and ASCO meeting abstract searches were conducted to identify clinical trials reporting alopecia. Meta-analysis was conducted utilizing fixed- or random-effects models.

RESULTS

The calculated overall incidence of all-grade alopecia was 14.7% [95% confidence interval (CI) 12.6% to 17.2%]-lowest with bortezomib, 2.2% (95% CI 0.4% to 10.9%), and highest with vismodegib, 56.9% (95% CI 50.5% to 63.1%). There was an increased risk of all-grade alopecia [relative risk (RR), 7.9 (95% CI 6.2-10.09, P ≤ 0.01)] compared with placebo, but when compared with chemotherapy, the risk was lower [RR, 0.32 (95% CI 0.2-0.55, P ≤ 0.01)].

CONCLUSIONS

Targeted therapies are associated with an increased risk of alopecia.

Efficacy of therapy with bortezomib in solid tumors: a review based on 32 clinical trials

The ubiquitin-proteasome system is a major pathway for protein degradation, so that proteasome is now considered as an important target for drug discovery. Bortezomib, the first US FDA-approved proteasome inhibitor now used as a front-line treatment for multiple myeloma. To better understand the effects of bortezomib in cancer treatment, we carried out a review based on 32 published clinical trials to determine whether bortezomib will benefit patients with solid tumors. Information of complete response, partial response, stable disease and objective response rate was collected to assess clinical outcomes. A lack of therapeutic effects was observed when bortezomib was used as a single agent. Meanwhile, when bortezomib treatment was combined with other agents, bortezomib offered no statistically significant response versus these agents alone. High-quality studies are required to better understand the clinically effects of bortezomib and the development of a new generation of proteasome inhibitors is absolutely necessary.

Comprehensive Evaluation of Nuclear Factor-κΒ Expression Patterns in Non-Small Cell Lung Cancer

Nuclear factor (NF)-κB signalling is required for lung adenocarcinoma development in mice, and both of its subunits RelA and RelB were independently reported to be highly expressed in human non-small cell lung cancer (NSCLC). To comprehensively examine NF-κB expression in NSCLC, we analyzed serial sections of primary tumor samples from 77 well-documented patients (36 adenocarcinomas, 40 squamous cell carcinomas and 3 large cell carcinomas) for immunoreactivity of RelA, RelB, P50, and P52/P100. Tumor and intratumoral stroma areas were discriminated based on proliferating cell nuclear antigen immunoreactivity and inflammatory infiltration was assessed in intratumoral stroma areas. NF-κB immunoreactivity was quantified by intensity, extent, and nuclear localization and was cross-examined with tumor cell proliferation, inflammatory infiltration, and clinical-pathologic data. We found that the expression of the different NF-κB subunits was not concordant, warranting our integral approach. Overall, RelA, RelB, and P50 were expressed at higher levels compared with P52/P100. However, RelA and P50 were predominantly expressed in intratumoral stroma, but RelB in tumor cells. Importantly, tumor area RelA expression was correlated with the intensity of inflammatory infiltration, whereas RelB expression was identified in proliferating tumor cells. Using multiple logistic regression, we identified that tumor RelB expression was an independent predictor of lymph node metastasis, and tumor P50 was an independent predictor of TNM6 stage IIB or higher, whereas tumor RelA was an independent predictor of inflammatory infiltration. We conclude that pathologic studies of NF-κB expression in cancer should include multiple pathway components. Utilizing such an approach, we identified intriguing associations between distinct NF-κB subunits and clinical and pathologic features of NSCLC.

ATF4 Gene Network Mediates Cellular Response to the Anticancer PAD Inhibitor YW3-56 in Triple-Negative Breast Cancer Cells

We previously reported that a pan-PAD inhibitor, YW3-56, activates p53 target genes to inhibit cancer growth. However, the p53-independent anticancer activity and molecular mechanisms of YW3-56 remain largely elusive. Here, gene expression analyses found that ATF4 target genes involved in endoplasmic reticulum (ER) stress response were activated by YW3-56. Depletion of ATF4 greatly attenuated YW3-56-mediated activation of the mTORC1 regulatory genes SESN2 and DDIT4. Using the ChIP-exo method, high-resolution genomic binding sites of ATF4 and CEBPB responsive to YW3-56 treatment were generated. In human breast cancer cells, YW3-56-mediated cell death features mitochondria depletion and autophagy perturbation. Moreover, YW3-56 treatment effectively inhibits the growth of triple-negative breast cancer xenograft tumors in nude mice. Taken together, we unveiled the anticancer mechanisms and therapeutic potentials of the pan-PAD inhibitor YW3-56.

Carfilzomib demonstrates broad anti-tumor activity in pre-clinical non-small cell and small cell lung cancer models

BACKGROUND

Carfilzomib (CFZ) is a proteasome inhibitor that selectively and irreversibly binds to its target and has been approved in the US for treatment of relapsed and refractory multiple myeloma. Phase 1B studies of CFZ reported signals of clinical activity in solid tumors, including small cell lung cancer (SCLC). The aim of this study was to investigate the activity of CFZ in lung cancer models.

METHODS

A diverse panel of human lung cancer cell lines and a SHP77 small cell lung cancer xenograft model were used to investigate the anti-tumor activity of CFZ.

RESULTS

CFZ treatment inhibited both the constitutive proteasome and the immunoproteasome in lung cancer cell lines. CFZ had marked anti-proliferative activity in A549, H1993, H520, H460, and H1299 non-small cell lung cancer (NSCLC) cell lines, with IC50 values after 96 hour exposure from <1.0 nM to 36 nM. CFZ had more variable effects in the SHP77 and DMS114 SCLC cell lines, with IC50 values at 96 hours from <1 nM to 203 nM. Western blot analysis of CFZ-treated H1993 and SHP77 cells showed cleavage of poly ADP ribose polymerase (PARP) and caspase-3, indicative of apoptosis, and induction of microtubule-associated protein-1 light chain-3B (LC3B), indicative of autophagy. In SHP77 flank xenograft tumors, CFZ monotherapy inhibited tumor growth and prolonged survival, while no additive or synergistic anti-tumor efficacy was observed for CFZ + cisplatin (CDDP).

CONCLUSIONS

CFZ demonstrated anti-proliferative activity in lung cancer cell lines in vitro and resulted in a significant survival advantage in mice with SHP77 SCLC xenografts, supporting further pre-clinical and clinical investigations of CFZ in NSCLC and SCLC.

An analysis of the safety profile of proteasome inhibitors for treating various cancers

INTRODUCTION

Emerging evidence demonstrates that the ubiquitin-proteasome pathway is a promising target for cancer therapy. Bortezomib (Velcade) exhibits great efficacy against multiple myeloma (MM) since the first clinical application. However, there are still several limitations associated with the use of bortezomib, including severe toxicities. To overcome bortezomib's shortcomings and to improve its safety profile, several second-generation proteasome inhibitors, for example, carfilzomib, ixazomib, oprozomib and marizomib, have been developed and currently tested in various clinical trials.

AREAS COVERED

A literature search was carried out using PubMed and Google Scholar. The activity and safety profiling of proteasome inhibitors in treatment of various cancers were reviewed.

EXPERT OPINION

Bortezomib, as a single or in combination therapy, demonstrates efficacy against MM or other hematological malignancies in clinical settings. However, it encounters two major problems, the acquired resistance and the severe side effects. Future direction in bortezomib-based therapy should focus on how to increase or retain its efficacy but improve its safety profile through, for example, rational combination therapies. Second-generation proteasome inhibitors have shown benefits in both overcoming bortezomib resistance and reducing related side effects, although these encouraging results should be further confirmed in a larger clinic population.

Combined autophagy and proteasome inhibition: a phase 1 trial of hydroxychloroquine and bortezomib in patients with relapsed/refractory myeloma

The efficacy of proteasome inhibition for myeloma is limited by therapeutic resistance, which may be mediated by activation of the autophagy pathway as an alternative mechanism of protein degradation. Preclinical studies demonstrate that autophagy inhibition with hydroxychloroquine augments the antimyeloma efficacy of the proteasome inhibitor bortezomib. We conducted a phase I trial combining bortezomib and hydroxychloroquine for relapsed or refractory myeloma. We enrolled 25 patients, including 11 (44%) refractory to prior bortezomib. No protocol-defined dose-limiting toxicities occurred, and we identified a recommended phase 2 dose of hydroxychloroquine 600 mg twice daily with standard doses of bortezomib, at which we observed dose-related gastrointestinal toxicity and cytopenias. Of 22 patients evaluable for response, 3 (14%) had very good partial responses, 3 (14%) had minor responses, and 10 (45%) had a period of stable disease. Electron micrographs of bone marrow plasma cells collected at baseline, after a hydroxychloroquine run-in, and after combined therapy showed therapy-associated increases in autophagic vacuoles, consistent with the combined effects of increased trafficking of misfolded proteins to autophagic vacuoles and inhibition of their degradative capacity. Combined targeting of proteasomal and autophagic protein degradation using bortezomib and hydroxychloroquine is therefore feasible and a potentially useful strategy for improving outcomes in myeloma therapy.

Incidence and risk of cardiotoxicity associated with bortezomib in the treatment of cancer: a systematic review and meta-analysis

Background

We conducted a systematic review and meta-analysis to clarify the incidence and risk of cardiotoxicity associated with bortezomib in cancer patients.

Methods

Databases from PubMed, Web of Science and abstracts presented at ASCO meeting up to July 31, 2013 were searched to identify relevant studies. Eligible studies included prospective phase II and III trials evaluating bortezomib in cancer patients with adequate data on cardiotoxicity. Statistical analyses were conducted to calculate the summary incidence, odds ratio (OR) and 95% confidence intervals (CIs) by using either random effects or fixed effect models according to the heterogeneity of included studies.

Results

A total of 5718 patients with a variety of malignancies from 25 clinical trials were included in our analysis. The incidence of all-grade and high-grade cardiotoxicity associated with bortezomib was 3.8% (95%CI: 2.6–5.6%) and 2.3% (1.6–3.5%), with a mortality of 3.0% (1.4–6.5%). Patients treated with bortezomib did not significantly increase the risk of all-grade (OR 1.15, 95%CI: 0.82–1.62, p = 0.41) and high-grade (OR 1.13, 95%CI: 0.58–2.24, p = 0.72) cardiotoxicity compared with patients treated with control medication. Sub-group analysis showed that the incidence of cardiotoxicity varied with tumor types, treatment regimens and phases of trials. No evidence of publication bias was observed.

Conclusions

The use of bortezomib does not significantly increase the risk of cardiotoxicity compared to control patients. Further studies are recommended to investigate this association and risk differences among different tumor types, treatment regimens and phases of trials.

Extending survival of stage IV non-small cell lung cancer

Most of patients with newly diagnosed non-small cell lung cancer (NSCLC) present with locally advanced or metastatic disease. In this setting the goal of treatment is to prolong survival and to control disease- and treatment-related symptoms. Currently systemic cytotoxic chemotherapy remains the first-line treatment for most patients with stage IV NSCLC, but preferred treatments are now defined by histology and based on the presence of specific molecular abnormalities. In first-line the combination of platinum plus pemetrexed with or without bevacizumab is a reasonable choice in patients with non-squamous NSCLC. Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) as first-line therapy are the recommended for patients with EGFR-sensitizing mutations. A small-molecule TKI of anaplastic lymphoma kinase (ALK), crizotinib, showed pronounced clinical activity in the treatment of patients with NSCLC positive for EML4-ALK and it has rapidly entered into daily clinical practice. Currently no agents are specifically approved for the treatment of squamous cell carcinoma of the lung. Second-line treatments include docetaxel, pemetrexed, or erlotinib as single agents. There is a growing evidence that cytotoxics are better than EGFR-TKIs in EGFR wild-type patients. In the setting of the third line, the only approved agent is erlotinib. In elderly patients with good performance status (PS), doublet chemotherapy including platinum should not be excluded, especially for those patients 70-75 years of age without comorbidities. The better selection of patients, the identification of specific predictive biomarkers, a reasonable sequencing of all active and available treatments, including targeted therapies and cytotoxic, may significantly contribute to extend the natural history of stage IV NSCLC.

Bortezomib antagonizes microtubule-interfering drug-induced apoptosis by inhibiting G2/M transition and MCL-1 degradation

Inhibition of the proteasome is considered as a promising strategy to sensitize cancer cells to apoptosis. Recently, we demonstrated that the proteasome inhibitor Bortezomib primes neuroblastoma cells to TRAIL-induced apoptosis. In the present study, we investigated whether Bortezomib increases chemosensitivity of neuroblastoma cells. Unexpectedly, we discover an antagonistic interaction of Bortezomib and microtubule-interfering drugs. Bortezomib significantly attenuates the loss of cell viability and induction of apoptosis on treatment with Taxol and different vinca alkaloids but not with other chemotherapeutics, that is, Doxorubicin and Cisplatinum. Importantly, Bortezomib inhibits G2/M transition by inhibiting proteasomal degradation of cell cycle regulatory proteins such as p21, thereby preventing cells to enter mitosis, the cell cycle phase in which they are most vulnerable to antitubulin chemotherapeutics. Consequently, Bortezomib counteracts Taxol-induced mitotic arrest and polyploidy, as shown by reduced expression of PLK1 and phosphorylated histone H3. In addition, Bortezomib antagonizes Taxol-mediated degradation of MCL-1 during mitotic arrest by preventing cells to enter mitosis and by inhibiting the proteasome. Downregulation of MCL-1 is critically required for Taxol-induced apoptosis, as overexpression of a phosphomutant MCL-1 variant, which is resistant to degradation, significantly diminishes Taxol-triggered apoptosis. Vice versa, attenuation of Bortezomib-mediated accumulation of MCL-1 by knockdown of MCL-1 significantly enhances Taxol/Bortezomib-induced apoptosis. Thus, Bortezomib rescues Taxol-induced apoptosis by inhibiting G2/M transition and mitigating MCL-1 degradation. The identification of this antagonistic interaction of Bortezomib and microtubule-targeted drugs has important implications for the design of Bortezomib-based combination therapies.

Targeted therapy and new anticancer drugs in advanced disease

The development of targeted therapies in lung cancer (mainly non-small cell lung cancer) has led to improvement in clinical outcomes and a more personalized approach to the management of these patients. This article discusses the main categories of novel targeted agents and the evidence behind their use.

BAK and NOXA are critical determinants of mitochondrial apoptosis induced by bortezomib in mesothelioma

Based on promising preclinical efficacy associated with the 20S proteasome inhibitor bortezomib in malignant pleural mesothelioma (MPM), two phase II clinical trials have been initiated (EORTC 08052 and ICORG 05–10). However, the potential mechanisms underlying resistance to this targeted drug in MPM are still unknown. Functional genetic analyses were conducted to determine the key mitochondrial apoptotic regulators required for bortezomib sensitivity and to establish how their dysregulation may confer resistance. The multidomain proapoptotic protein BAK, but not its orthologue BAX, was found to be essential for bortezomib-induced apoptosis in MPM cell lines. Immunohistochemistry was performed on tissues from the ICORG-05 phase II trial and a TMA of archived mesotheliomas. Loss of BAK was found in 39% of specimens and loss of both BAX/BAK in 37% of samples. However, MPM tissues from patients who failed to respond to bortezomib and MPM cell lines selected for resistance to bortezomib conserved BAK expression. In contrast, c-Myc dependent transactivation of NOXA was abrogated in the resistant cell lines. In summary, the block of mitochondrial apoptosis is a limiting factor for achieving efficacy of bortezomib in MPM, and the observed loss of BAK expression or NOXA transactivation may be relevant mechanisms of resistance in the clinic.

Acquired resistance to EGFR inhibitors is associated with a manifestation of stem cell-like properties in cancer cells

Acquired resistance to EGF receptor (EGFR) tyrosine kinase inhibitor (TKI) is a critical problem in the treatment of lung cancer. Although several mechanisms have been shown to be responsible for acquired resistance, all mechanisms have not been uncovered. In this study, we investigated the molecular and cellular profiles of the acquired resistant cells to EGFR-TKI in EGFR-mutant lung cancers. Four EGFR-mutant cell lines were exposed to gefitinib by stepwise escalation and high-concentration exposure methods, and resistant sublines to gefitinib were established. The molecular profiles and cellular phenotypes of these resistant sublines were characterized. Although previously reported, alterations including secondary EGFR T790M mutation, MET amplification, and appearance of epithelial-to-mesenchymal transition (EMT) features were observed, these 2 drug-exposure methods revealed different resistance mechanisms. The resistant cells with EMT features exhibited downregulation of miRNA-200c by DNA methylation. Furthermore, the HCC827-derived subline characterized by the high-concentration exposure method exhibited not only EMT features but also stem cell-like properties, including aldehyde dehydrogenase isoform 1 (ALDH1A1) overexpression, increase of side-population, and self-renewal capability. Resistant sublines with stem cell-like properties were resistant to conventional chemotherapeutic agents but equally sensitive to histone deacetylase and proteasome inhibitors, compared with their parental cells. ALDH1A1 was upregulated in clinical samples with acquired resistance to gefitinib. In conclusion, our study indicates that the manner of EGFR-TKI exposure influences the mechanism of acquired resistance and the appearance of stem cell-like property with EGFR-TKI treatment.

Integration of targeted therapy in the management of locally advanced, unresectable non-small-cell lung cancer

SUMMARY The standard of care for unresectable, locally advanced non-small-cell lung cancer (NSCLC; stage IIIA and IIIB) in the past decade has been concomitant platinum-based chemoradiation therapy. Unfortunately, a plateau has been reached in terms of response and survival rates with the present chemotherapeutic paradigm. Targeted biological agents have significantly altered the treatment landscape for stage IV NSCLC and offer an opportunity to do the same for locally advanced NSCLC. While some early trials using unselected patients have shown modest promise for several biologic agents, the overall data remain mixed. One limitation of these trials has been the lack of patient enrichment based on molecular phenotype most likely to benefit from a particular targeted therapy. This review summarizes the most recent data for select classes of targeted agents being tested in the locally advanced NSCLC setting, and gives insights into future developments in this clinical area.

A phase 1 Bayesian dose selection study of bortezomib and sunitinib in patients with refractory solid tumor malignancies

BACKGROUND

This phase 1 trial utilising a Bayesian continual reassessment method evaluated bortezomib and sunitinib to determine the maximum tolerated dose (MTD), dose-limiting toxicities (DLT), and recommended doses of the combination.

METHODS

Patients with advanced solid organ malignancies were enrolled and received bortezomib weekly with sunitinib daily for 4 weeks, every 6 weeks. Initial doses were sunitinib 25 mg and bortezomib 1 mg m(-2). Cohort size and dose level estimation was performed utilising the Escalation with Overdose Control (EWOC) adaptive method. Seven dose levels were evaluated; initially, sunitinib was increased to a goal dose of 50 mg with fixed bortezomib, then bortezomib was increased. Efficacy assessment occurred after each cycle using RECIST criteria.

RESULTS

Thirty patients were evaluable. During sunitinib escalation, DLTs of grade 4 thrombocytopenia (14%) and neutropenia (6%) at sunitinib 50 mg and bortezomib 1.3 mg m(-2) were seen. Subsequent experience showed tolerability and activity for sunitinib 37.5 mg and bortezomib 1.9 mg m(-2). Common grade 3/4 toxicities were neutropenia, thrombocytopenia, hypertension, and diarrhoea. The recommended doses for further study are bortezomib 1.9 mg m(-2) and sunitinib 37.5 mg. Four partial responses were seen. Stable disease >6 months was noted in an additional six patients.

CONCLUSION

Bortezomib and sunitinib are well tolerated and have anticancer activity, particularly in thyroid cancer. A phase 2 study of this combination in thyroid cancer patients is planned.

Targeting NF-κB in mouse models of lung adenocarcinoma

Xue et al. demonstrate response and increased survival but development of acquired resistance to proteasome and inhibitor-κB kinase inhibitors targeting NF-κB activation in adenocarcinomas of Kras-activated, p53-deficient mice.

Phase-I/II study of bortezomib in combination with carboplatin and bevacizumab as first-line therapy in patients with advanced non-small-cell lung cancer

BACKGROUND

This study aimed to establish the maximum tolerated dose (MTD) of weekly bortezomib in combination with fixed standard doses of carboplatin and bevacizumab, and to estimate the efficacy (response rate and progression free survival [PFS]) and safety of combination therapy with carboplatin, bortezomib, and bevacizumab as first-line therapy in patients with advanced non-small-cell lung cancer (NSCLC).

METHODS

Patients were assigned to three dose levels of weekly bortezomib with the fixed standard doses of carboplatin AUC 6 and bevacizumab (15 mg/kg) every 3 weeks using a standard phase-I design. Bortezomib doses were 1.3 mg/m, 1.6 mg/m, and 1.8 mg/m weekly on day 1 and day 8 of every 3-week cycle. A maximum of six cycles was administered. Patients with complete, partial response or stable disease were continued on single-agent bevacizumab (15 mg/kg every 3 weeks) as maintenance therapy. In phase II, either level III or MTD was administered to evaluate the efficacy and safety of the combination in first-line treatment of advanced NSCLC.

RESULTS

Sixteen patients were enrolled (three, four, and nine patients in dose level I, II, and III, respectively). There was no predefined dose limiting toxicity in cycle 1 in all 16 patients. The recommended phase-II dose is bortezomib 1.8 mg/m weekly on day 1 and day 8 in combination with carboplatin AUC 6 and bevacizumab 15 mg/kg on every 21-day cycle. Totally 9 patients were treated at the recommended phase-II dose level. The most common treatment related grade-3/4 toxicities during the subsequent cycles were thrombocytopenia (58%), lymphopenia (25%), neutropenia (12%), and diarrhea (25%). The grade-1/2 neuropathy was seen in 7 out of 16 patients (44%). The response rate, PFS, and overall survival in all patients were 37.5% (95%CI 13.8%-61.2%), 5.0 months (95%CI: 3.1-8.4), 9.9 months (95% CI: 8.2-14.1), and among the 9 patients in phase-II portion are 44% (95%CI 15.3%-77.3%), 5.5 months (95%CI: 3.1-2.2) and 10.9 months (95%CI: 8.0-14.1).

CONCLUSION

The recommended phase-II dose for this combination is: carboplatin AUC 6, bevacizumab 15 mg/kg on day 1 and bortezomib 1.8 mg/m on day 1 and day 8 on every 21-day cycle. The regimen was very well tolerated with interesting clinical activity in first-line treatment of NSCLC.