scholarly journals Regulation of signal transduction pathways in colorectal cancer: implications for therapeutic resistance

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e12338
Author(s):  
Yeelon Yeoh ◽  
Teck Yew Low ◽  
Nadiah Abu ◽  
Pey Yee Lee

Resistance to anti-cancer treatments is a critical and widespread health issue that has brought serious impacts on lives, the economy and public policies. Mounting research has suggested that a selected spectrum of patients with advanced colorectal cancer (CRC) tend to respond poorly to both chemotherapeutic and targeted therapeutic regimens. Drug resistance in tumours can occur in an intrinsic or acquired manner, rendering cancer cells insensitive to the treatment of anti-cancer therapies. Multiple factors have been associated with drug resistance. The most well-established factors are the emergence of cancer stem cell-like properties and overexpression of ABC transporters that mediate drug efflux. Besides, there is emerging evidence that signalling pathways that modulate cell survival and drug metabolism play major roles in the maintenance of multidrug resistance in CRC. This article reviews drug resistance in CRC as a result of alterations in the MAPK, PI3K/PKB, Wnt/β-catenin and Notch pathways.

Cells ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 8 ◽  
Author(s):  
Xueqiao Jiao ◽  
Xianling Qian ◽  
Longyuan Wu ◽  
Bo Li ◽  
Yi Wang ◽  
...  

Cancer ranks as the second leading cause of death worldwide, causing a large social and economic burden. However, most anti-cancer treatments face the problems of tumor recurrence and metastasis. Therefore, finding an effective cure for cancer needs to be solved urgently. Recently, the discovery of cancer stem cells (CSCs) provides a new orientation for cancer research and therapy. CSCs share main characteristics with stem cells and are able to generate an entire tumor. Besides, CSCs usually escape from current anti-cancer therapies, which is partly responsible for tumor recurrence and poor prognosis. microRNAs (miRNAs) belong to small noncoding RNA and regulate gene post-transcriptional expression. The dysregulation of miRNAs leads to plenty of diseases, including cancer. The aberrant miRNA expression in CSCs enhances stemness maintenance. In this review, we summarize the role of miRNAs on CSCs in the eight most common cancers, hoping to bridge the research of miRNAs and CSCs with clinical applications. We found that miRNAs can act as tumor promoter or suppressor. The dysregulation of miRNAs enhances cell stemness and contributes to tumor metastasis and therapeutic resistance via the formation of feedback loops and constitutive activation of carcinogenic signaling pathways. More importantly, some miRNAs may be potential targets for diagnosis, prognosis, and cancer treatments.


2020 ◽  
Vol 21 (15) ◽  
pp. 5353 ◽  
Author(s):  
Hsiuying Wang

Colorectal cancer (CRC) is the third leading cause of cancer death in the world, and its incidence is rising in developing countries. Treatment with 5-Fluorouracil (5-FU) is known to improve survival in CRC patients. Most anti-cancer therapies trigger apoptosis induction to eliminate malignant cells. However, de-regulated apoptotic signaling allows cancer cells to escape this signaling, leading to therapeutic resistance. Treatment resistance is a major challenge in the development of effective therapies. The microRNAs (miRNAs) play important roles in CRC treatment resistance and CRC progression and apoptosis. This review discusses the role of miRNAs in contributing to the promotion or inhibition of apoptosis in CRC and the role of miRNAs in modulating treatment resistance in CRC cells.


2020 ◽  
Vol 48 (3) ◽  
pp. 538-551 ◽  
Author(s):  
Christine Leopold ◽  
Rebecca L. Haffajee ◽  
Christine Y. Lu ◽  
Anita K. Wagner

Over the past decades, anti-cancer treatments have evolved rapidly from cytotoxic chemotherapies to targeted therapies including oral targeted medications and injectable immunooncology and cell therapies. New anti-cancer medications come to markets at increasingly high prices, and health insurance coverage is crucial for patient access to these therapies. State laws are intended to facilitate insurance coverage of anti-cancer therapies.Using Massachusetts as a case study, we identified five current cancer coverage state laws and interviewed experts on their perceptions of the relevance of the laws and how well they meet the current needs of cancer care given rapid changes in therapies. Interviewees emphasized that cancer therapies, as compared to many other therapeutic areas, are unique because insurance legislation targets their coverage. They identified the oral chemotherapy parity law as contributing to increasing treatment costs in commercial insurance. For commercial insurers, coverage mandates combined with the realities of new cancer medications — including high prices and often limited evidence of efficacy at approval — compound a difficult situation. Respondents recommended policy approaches to address this challenging coverage environment, including the implementation of closed formularies, the use of cost-effectiveness studies to guide coverage decisions, and the application of value-based pricing concepts. Given the evolution of cancer therapeutics, it may be time to evaluate the benefits and challenges of cancer coverage mandates.


2021 ◽  
Vol 10 ◽  
Author(s):  
Aukie Hooglugt ◽  
Miesje M. van der Stoel ◽  
Reinier A. Boon ◽  
Stephan Huveneers

Solid tumors are dependent on vascularization for their growth. The hypoxic, stiff, and pro-angiogenic tumor microenvironment induces angiogenesis, giving rise to an immature, proliferative, and permeable vasculature. The tumor vessels promote tumor metastasis and complicate delivery of anti-cancer therapies. In many types of tumors, YAP/TAZ activation is correlated with increased levels of angiogenesis. In addition, endothelial YAP/TAZ activation is important for the formation of new blood and lymphatic vessels during development. Oncogenic activation of YAP/TAZ in tumor cell growth and invasion has been studied in great detail, however the role of YAP/TAZ within the tumor endothelium remains insufficiently understood, which complicates therapeutic strategies aimed at targeting YAP/TAZ in cancer. Here, we overview the upstream signals from the tumor microenvironment that control endothelial YAP/TAZ activation and explore the role of their downstream targets in driving tumor angiogenesis. We further discuss the potential for anti-cancer treatments and vascular normalization strategies to improve tumor therapies.


Author(s):  
Wentao Tian ◽  
Yi Liu ◽  
Chenghui Cao ◽  
Yue Zeng ◽  
Yue Pan ◽  
...  

Chronic stress is common among cancer patients due to the psychological, operative, or pharmaceutical stressors at the time of diagnosis or during the treatment of cancers. The continuous activations of the hypothalamic-pituitary-adrenal (HPA) axis and the sympathetic nervous system (SNS), as results of chronic stress, have been demonstrated to take part in several cancer-promoting processes, such as tumorigenesis, progression, metastasis, and multi-drug resistance, by altering the tumor microenvironment (TME). Stressed TME is generally characterized by the increased proportion of cancer-promoting cells and cytokines, the reduction and malfunction of immune-supportive cells and cytokines, augmented angiogenesis, enhanced epithelial-mesenchymal transition, and damaged extracellular matrix. For the negative effects that these alterations can cause in terms of the efficacies of anti-cancer treatments and prognosis of patients, supplementary pharmacological or psychotherapeutic strategies targeting HPA, SNS, or psychological stress may be effective in improving the prognosis of cancer patients. Here, we review the characteristics and mechanisms of TME alterations under chronic stress, their influences on anti-cancer therapies, and accessory interventions and therapies for stressed cancer patients.


2021 ◽  
Vol 8 ◽  
Author(s):  
Kate Dinneen ◽  
Anne-Marie Baird ◽  
Ciara Ryan ◽  
Orla Sheils

Gastroesophageal junction adenocarcinomas (GEJA) have dramatically increased in incidence in the western world since the mid-20th century. Their prognosis is poor, and conventional anti-cancer therapies do not significantly improve survival outcomes. These tumours are comprised of a heterogenous population of both cancer stem cells (CSC) and non-CSCs, with the former playing a crucial role in tumorigenesis, metastasis and importantly drug resistance. Due to the ability of CSCs to self-replicate indefinitely, their resistance to anti-cancer therapies poses a significant barrier to effective treatment of GEJA. Ongoing drug development programmes aim to target and eradicate CSCs, however their characterisation and thus identification is difficult. CSC regulation is complex, involving an array of signalling pathways, which are in turn influenced by a number of entities including epithelial mesenchymal transition (EMT), microRNAs (miRNAs), the tumour microenvironment and epigenetic modifications. Identification of CSCs commonly relies on the expression of specific cell surface markers, yet these markers vary between different malignancies and indeed are often co-expressed in non-neoplastic tissues. Development of targeted drug therapies against CSCs thus requires an understanding of disease-specific CSC markers and regulatory mechanisms. This review details the current knowledge regarding CSCs in GEJA, with particular emphasis on their role in drug resistance.


2020 ◽  
Vol 13 ◽  
pp. 175628482091752 ◽  
Author(s):  
Gol Golshani ◽  
Yue Zhang

Immunotherapy is a new and exciting modality of cancer treatments. Its role in gastrointestinal malignancies has been promising, especially in advanced disease. Although various therapies are available for treatment of advanced colorectal cancer, survival rates for these patients remain very poor. The application of immunotherapy in colorectal cancer has shown remarkable results for a subset of patients with mismatch-repair-deficient mutations or microsatellite instability in their tumors. This literature review evaluates the current role of immunotherapy in advanced colorectal cancer, potential challenges clinicians face with immunotherapy-based regimens, and the possible future approach of combined modality immunotherapy.


2017 ◽  
Vol 35 (4_suppl) ◽  
pp. 642-642 ◽  
Author(s):  
Jan Stenvang ◽  
Christine Hjorth Andreassen ◽  
Nils Brünner

642 Background: In metastatic colorectal cancer (mCRC) only 3 cytotoxic drugs (oxaliplatin, irinotecan and fluorouracil (5-FU)) are approved and the first and second line response rates are about 50% and 10-15%, respectively. Thus, new treatment options are needed. Novel anti-cancer drug candidates are primarily tested in an environment of drug resistance and the majority of novel drug candidates fail during clinical development. Therefore, “repurposing” of drugs has emerged as a promising strategy to apply established drugs in novel indications. The aim of this project was to screen established anti-cancer drugs to identify candidates for testing in mCRC patients relapsing on standard therapy. Methods: We applied 3 parental (drug sensitive) CRC cell lines (HCT116, HT29 and LoVo) and for each cell line also an oxaliplatin and irinotecan (SN38) resistant cell line. We obtained 129 FDA approved anti-cancer drugs from the Developmental Therapeutics Program (DTP) at the National Cancer Institute (NCI) ( https://dtp.cancer.gov/ ). The parental HT29 cell line and the drug resistant sublines HT29-SN38 and HT29-OXPT were exposed to 3 concentrations of each of the anti-cancer drugs. The effect on cell viability was analyzed by MTT assays. Nine of the drugs were analyzed for effect in the LoVo and HCT116 and the SN38- and oxaliplatin-resistant derived cell lines. Results: None of the drugs caused evident differential response between the resistant and sensitive cells or between the SN38 and oxaliplatin resistant cells. The screening confirmed the resistance as the cells displayed resistance to drugs in the same class as the one they were made resistant to. Of the drugs, 45 decreased cell viability in the HT29 parental and oxaliplatin- or SN-38 resistant cell lines. Nine drugs were tested in all nine CRC cell lines and eight decrease cell viability in the nine cell lines. These included drugs in different classes such as epigenetic drugs, antibiotics, mitotic inhibitors and targeted therapies. Conclusions: This study revealed several possible new “repurposing” drugs for CRC therapy, by showing that 45 FDA-approved anti-cancer drugs decrease cell viability in CRC cell lines with acquired drug resistance.


2016 ◽  
Author(s):  
Yoshitaka Yagi ◽  
Hiroaki Ozasa ◽  
Takahiro Tsuji ◽  
Yuichi Sakamori ◽  
Takeshi Nomizo ◽  
...  

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