Topical Collection "Drug Resistance and Novel Therapies in Cancers"

Editor

Collection Editor
Prof. Zhixiang Wang

Signal Transduction Research Group, Department of Medical Genetics, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Canada
Website | E-Mail
Phone: +1-780-492-0710
Fax: +1-780-492-1998
Interests: ErbB receptors; cell signaling; protein trafficking; breast cancer; small GTPases and cell cycle

Topical Collection Information

Dear Colleagues,

Cancer is among the leading causes of mortality in developed countries. Despite advances in treatment in all settings, disease recurrence and progression remains a major obstacle to therapy. One of the main clinical issues is the development of drug resistance. Drug resistance exists in two forms: Acquired resistance, where the drug is initially efficient but becomes ineffective over time, while intrinsic resistance occurs when a drug is ineffective from the beginning of treatment. The hallmarks of drug resistance in cancers include sustained tumor cell proliferation, insensitive to growth suppressors, resisting cell death, and active invasion.

The early drugs used in cancer treatment are all of chemical origin, and as thus, drug resistance is also called chemoresistance in cancer. However, with the development of novel cancer treatment agents, such as hormones, cytokines, antibodies, antisense oligonucleotides and siRNAs, cancer drugs now could include any agent that is used to treat cancer patients. Therefore the term drug resistance in cancer could be used to cover resistance to any cancer treatment agents.

Through intensive studies, multiple mechanisms have been identified for the development of drug resistance. In general, drug resistance could arise due to decreased intracellular drug concentrations, alterations of drug targets, epigenetic modification, and activation of certain signaling cascades These mechanisms include drug inactivation, drug target alteration, drug efflux, DNA damage repair, cell death inhibition, the epithelial-mesenchymal transition (EMT), and epigenetic modifications.

Many strategies have been developed to combat drug resistance, either by combining the currently available therapies or by developing novel therapies. While new chemotherapeutic agents are still developed and chemotherapy is still standard-of-care in the treatment of most cancers, the focus has shift to the development and application of novel therapeutic agents for immunotherapy and targeted therapy due to the improved understanding of tumor biology and the hallmarks of cancers. Targeted therapies have frequently been used in combination with chemotherapeutic agents and radiotherapy in some cases.

Prof. Dr. Zhixiang Wang
Collection Editor

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All papers will be peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the collection website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Cancers is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 1000 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • cancer
  • chemotherapy
  • novel therapy
  • drug resistance
  • multidrug resistance
  • intrinsic drug resistance
  • acquired drug resistance
  • metastasis
  • apoptosis
  • disease recurrence
  • targeted therapy
  • immunotherapy
  • hormones
  • cytokines
  • antibodies
  • antisense oligonucleotides
  • siRNAs

Published Papers (6 papers)

2018

Open AccessArticle Targeted Therapy-Resistant Melanoma Cells Acquire Transcriptomic Similarities with Human Melanoblasts
Cancers 2018, 10(11), 451; https://doi.org/10.3390/cancers10110451
Received: 11 October 2018 / Revised: 6 November 2018 / Accepted: 13 November 2018 / Published: 16 November 2018
PDF Full-text (1211 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
The mechanisms of adaptive and acquired drug resistance in tumors are not completely understood. So far, gene amplifications or mutations, leading to the reactivation of the MAPK or PI3K pathways have been described. In this study, we used two different methods to generate
[...] Read more.
The mechanisms of adaptive and acquired drug resistance in tumors are not completely understood. So far, gene amplifications or mutations, leading to the reactivation of the MAPK or PI3K pathways have been described. In this study, we used two different methods to generate human melanoblasts: (1) via differentiation from induced pluripotent stem cells (iPSCs) and (2) via dedifferentiation from melanocytes. The melanoblast transcriptomes were then compared to the transcriptome of MAPK inhibitor-resistant melanoma cells. We observed that the expression of genes associated with cell cycle control, DNA damage control, metabolism, and cancer was altered in both melanoblast populations and in both adaptive and acquired resistant melanoma samples, compared to drug-sensitive samples. However, genes involved in antigen presentation and cellular movement were only regulated in the melanoblast populations and in the acquired resistant melanoma samples, compared to the drug-sensitive samples. Moreover, melanocyte-derived melanoblasts and adaptive resistant melanoma samples were characterized by different expression levels of certain transcription factors or genes involved in the CDK5 pathway. In conclusion, we show here that in vitro models of human melanoblasts are very important tools to comprehend the expression profiles of drug-resistant melanoma. Full article
Figures

Figure 1

Open AccessReview NF-κB Signaling in Targeting Tumor Cells by Oncolytic Viruses—Therapeutic Perspectives
Cancers 2018, 10(11), 426; https://doi.org/10.3390/cancers10110426
Received: 4 October 2018 / Revised: 4 November 2018 / Accepted: 6 November 2018 / Published: 8 November 2018
PDF Full-text (1612 KB) | HTML Full-text | XML Full-text
Abstract
In recent years, oncolytic virotherapy became a promising therapeutic approach, leading to the introduction of a novel generation of anticancer drugs. However, despite evoking an antitumor response, introducing an oncolytic virus (OV) to the patient is still inefficient to overcome both tumor protective
[...] Read more.
In recent years, oncolytic virotherapy became a promising therapeutic approach, leading to the introduction of a novel generation of anticancer drugs. However, despite evoking an antitumor response, introducing an oncolytic virus (OV) to the patient is still inefficient to overcome both tumor protective mechanisms and the limitation of viral replication by the host. In cancer treatment, nuclear factor (NF)-κB has been extensively studied among important therapeutic targets. The pleiotropic nature of NF-κB transcription factor includes its involvement in immunity and tumorigenesis. Therefore, in many types of cancer, aberrant activation of NF-κB can be observed. At the same time, the activity of NF-κB can be modified by OVs, which trigger an immune response and modulate NF-κB signaling. Due to the limitation of a monotherapy exploiting OVs only, the antitumor effect can be enhanced by combining OV with NF-κB-modulating drugs. This review describes the influence of OVs on NF-κB activation in tumor cells showing NF-κB signaling as an important aspect, which should be taken into consideration when targeting tumor cells by OVs. Full article
Figures

Figure 1

Open AccessReview Systemic Therapy for Hepatocellular Carcinoma: Latest Advances
Cancers 2018, 10(11), 412; https://doi.org/10.3390/cancers10110412
Received: 2 October 2018 / Revised: 23 October 2018 / Accepted: 25 October 2018 / Published: 30 October 2018
PDF Full-text (427 KB) | HTML Full-text | XML Full-text
Abstract
Systemic therapy for hepatocellular carcinoma (HCC) has changed drastically since the introduction of the molecular targeted agent sorafenib in 2007. Although sorafenib expanded the treatment options for extrahepatic spread (EHS) and vascular invasion, making long-term survival of patients with advanced disease achievable to
[...] Read more.
Systemic therapy for hepatocellular carcinoma (HCC) has changed drastically since the introduction of the molecular targeted agent sorafenib in 2007. Although sorafenib expanded the treatment options for extrahepatic spread (EHS) and vascular invasion, making long-term survival of patients with advanced disease achievable to a certain extent, new molecular-targeted agents are being developed as alternatives to sorafenib due to shortcomings such as its low response rate and high toxicity. Every single one of the many drugs developed during the 10-year period from 2007 to 2016 was a failure. However, during the two-year period from 2017 through 2018, four drugs—regorafenib, lenvatinib, cabozantinib, and ramucirumab—emerged successfully from clinical trials in quick succession and became available for clinical use. The efficacy of combination therapy with transcatheter arterial chemoembolization (TACE) plus sorafenib was also first demonstrated in 2018. Recently, immune checkpoint inhibitors have been applied to HCC treatment and many phase III clinical trials are ongoing, not only on monotherapy with nivolumab, pembrolizumab, and tislelizumab, but also on combination therapy with checkpoint inhibitors, programmed death-1 (PD-1) or PD-ligand 1 (PD-L1) antibody plus a molecular targeted agent (bevacizumab) or the cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) antibody, tremelimumab. These combination therapies have shown higher response rates than PD-1/PD-L1 monotherapy alone, suggesting a synergistic effect by combination therapy in early phases; therefore, further results are eagerly awaited. Full article
Figures

Figure 1

Open AccessArticle Nafamostat Mesilate Enhances the Radiosensitivity and Reduces the Radiation-Induced Invasive Ability of Colorectal Cancer Cells
Cancers 2018, 10(10), 386; https://doi.org/10.3390/cancers10100386
Received: 19 September 2018 / Revised: 12 October 2018 / Accepted: 15 October 2018 / Published: 17 October 2018
PDF Full-text (2754 KB) | HTML Full-text | XML Full-text
Abstract
Neoadjuvant chemoradiotherapy followed by radical surgery is the standard treatment for patients with locally advanced low rectal cancer. However, several studies have reported that ionizing radiation (IR) activates nuclear factor kappa B (NF-κB) that causes radioresistance and induces matrix metalloproteinase (MMP)-2/-9, which promote
[...] Read more.
Neoadjuvant chemoradiotherapy followed by radical surgery is the standard treatment for patients with locally advanced low rectal cancer. However, several studies have reported that ionizing radiation (IR) activates nuclear factor kappa B (NF-κB) that causes radioresistance and induces matrix metalloproteinase (MMP)-2/-9, which promote tumor migration and invasion. Nafamostat mesilate (FUT175), a synthetic serine protease inhibitor, enhances the chemosensitivity to cytotoxic agents in digestive system cancer cells by inhibiting NF-κB activation. Therefore, we evaluated the combined effect of IR and FUT175 on cell proliferation, migration and invasion of colorectal cancer (CRC) cells. IR-induced upregulation of intranuclear NF-κB, FUT175 counteracted this effect. Moreover, the combination treatment suppressed cell viability and induced apoptosis. Similar effects were also observed in xenograft tumors. In addition, FUT175 prevented the migration and invasion of cancer cells caused by IR by downregulating the enzymatic activity of MMP-2/-9. In conclusion, FUT175 enhances the anti-tumor effect of radiotherapy through downregulation of NF-κB and reduces IR-induced tumor invasiveness by directly inhibiting MMP-2/-9 in CRC cells. Therefore, the use of FUT175 during radiotherapy might improve the efficacy of radiotherapy in patients with CRC. Full article
Figures

Figure 1

Open AccessArticle Energy Stress-Mediated Cytotoxicity in Tuberous Sclerosis Complex 2-Deficient Cells with Nelfinavir and Mefloquine Treatment
Cancers 2018, 10(10), 375; https://doi.org/10.3390/cancers10100375
Received: 21 August 2018 / Revised: 25 September 2018 / Accepted: 3 October 2018 / Published: 10 October 2018
PDF Full-text (2664 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
To find new anti-cancer drug therapies, we wanted to exploit homeostatic vulnerabilities within Tuberous Sclerosis Complex 2 (TSC2)-deficient cells with mechanistic target of rapamycin complex 1 (mTORC1) hyperactivity. We show that nelfinavir and mefloquine synergize to selectively evoke a cytotoxic response in TSC2-deficient
[...] Read more.
To find new anti-cancer drug therapies, we wanted to exploit homeostatic vulnerabilities within Tuberous Sclerosis Complex 2 (TSC2)-deficient cells with mechanistic target of rapamycin complex 1 (mTORC1) hyperactivity. We show that nelfinavir and mefloquine synergize to selectively evoke a cytotoxic response in TSC2-deficient cell lines with mTORC1 hyperactivity. We optimize the concentrations of nelfinavir and mefloquine to a clinically viable range that kill cells that lack TSC2, while wild-type cells tolerate treatment. This new clinically viable drug combination causes a significant level of cell death in TSC2-deficient tumor spheroids. Furthermore, no cell recovery was apparent after drug withdrawal, revealing potent cytotoxicity. Transcriptional profiling by RNA sequencing of drug treated TSC2-deficient cells compared to wild-type cells suggested the cytotoxic mechanism of action, involving initial ER stress and an imbalance in energy homeostatic pathways. Further characterization revealed that supplementation with methyl pyruvate alleviated energy stress and reduced the cytotoxic effect, implicating energy deprivation as the trigger of cell death. This work underpins a critical vulnerability with cancer cells with aberrant signaling through the TSC2-mTORC1 pathway that lack flexibility in homeostatic pathways, which could be exploited with combined nelfinavir and mefloquine treatment. Full article
Figures

Figure 1

Open AccessReview Mechanisms Underlying the Action and Synergism of Trastuzumab and Pertuzumab in Targeting HER2-Positive Breast Cancer
Cancers 2018, 10(10), 342; https://doi.org/10.3390/cancers10100342
Received: 8 August 2018 / Revised: 13 September 2018 / Accepted: 18 September 2018 / Published: 20 September 2018
PDF Full-text (1619 KB) | HTML Full-text | XML Full-text
Abstract
Human epidermal growth factor receptor (HER) 2 (HER2) is overexpressed in 20–30% of breast cancers. HER2 is a preferred target for treating HER2-positive breast cancer. Trastuzumab and pertuzumab are two HER2-targeted monoclonal antibodies approved by the Food and Drug Administration (FDA) to use
[...] Read more.
Human epidermal growth factor receptor (HER) 2 (HER2) is overexpressed in 20–30% of breast cancers. HER2 is a preferred target for treating HER2-positive breast cancer. Trastuzumab and pertuzumab are two HER2-targeted monoclonal antibodies approved by the Food and Drug Administration (FDA) to use as adjuvant therapy in combination with docetaxel to treat metastatic HER2-positive breast cancer. Adding the monoclonal antibodies to treatment regimen has changed the paradigm for treatment of HER2-positive breast cancer. Despite improving outcomes, the percentage of the patients who benefit from the treatment is still low. Continued research and development of novel agents and strategies of drug combinations is needed. A thorough understanding of the molecular mechanisms underlying the action and synergism of trastuzumab and pertuzumab is essential for moving forward to achieve high efficacy in treating HER2-positive breast cancer. This review examined and analyzed findings and hypotheses regarding the action and synergism of trastuzumab and pertuzumab and proposed a model of synergism based on available information. Full article
Figures

Figure 1

Back to Top