Melanoma subpopulations that rapidly escape MAPK pathway inhibition incur DNA damage and rely on stress signalling

AbstractDespite increasing numbers of effective anti-cancer therapies, successful treatment is limited by the development of drug resistance. While the contribution of genetic factors to drug resistance is undeniable, little is known about how drug-sensitive cells first evade drug action to proliferate in drug. Here we track the response of thousands of single melanoma cells to BRAF inhibitors and show that a subset escapes drug within the first 3 days of treatment. Cell-cycle re-entry occurs via a non-genetic mechanism involving activation of mTORC1 and ATF4, validated in cultures of patient biopsies. These escapees cycle periodically in drug, incur significant DNA damage, and out-proliferate non-escapees over extended treatment. Our work reveals a mutagenesis-prone, expanding subpopulation of early drug escapees that may seed development of permanent drug resistance.

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FAM129B is a novel regulator of Wnt/β-catenin signal transduction in melanoma cells

F1000Research ◽

10.12688/f1000research.2-134.v2 ◽

2013 ◽

Vol 2 ◽

pp. 134 ◽

Cited By ~ 11

Author(s):

Willliam Conrad ◽

Michael B Major ◽

Michele A Cleary ◽

Marc Ferrer ◽

Brian Roberts ◽

...

Keyword(s):

Large Scale ◽

Target Gene ◽

Mapk Pathway ◽

Melanoma Cells ◽

Luciferase Reporter ◽

Braf Inhibitors ◽

Sirna Screen ◽

Reporter Activity ◽

Fibrosarcoma Cells ◽

Interfering Rna

The inability of targeted BRAF inhibitors to produce long-lasting improvement in the clinical outcome of melanoma highlights a need to identify additional approaches to inhibit melanoma growth. Recent studies have shown that activation of the Wnt/β-catenin pathway decreases tumor growth and cooperates with ERK/MAPK pathway inhibitors to promote apoptosis in melanoma. Therefore, the identification of Wnt/β-catenin regulators may advance the development of new approaches to treat this disease. In order to move towards this goal we performed a large scale small-interfering RNA (siRNA) screen for regulators of β-catenin activated reporter activity in human HT1080 fibrosarcoma cells. Integrating large scale siRNA screen data with phosphoproteomic data and bioinformatics enrichment identified a protein, FAM129B, as a potential regulator of Wnt/β-catenin signaling. Functionally, we demonstrated that siRNA-mediated knockdown of FAM129B in A375 and A2058 melanoma cell lines inhibits WNT3A-mediated activation of a β-catenin-responsive luciferase reporter and inhibits expression of the endogenous Wnt/β-catenin target gene, AXIN2. We also demonstrate that FAM129B knockdown inhibits apoptosis in melanoma cells treated with WNT3A. These experiments support a role for FAM129B in linking Wnt/β-catenin signaling to apoptosis in melanoma.

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Hsp90 Inhibitors and the Reduction of Anti-Cancer Drug Resistance by Non-Genetic and Genetic Mechanisms

Pharmaceuticals ◽

10.3390/ph5090890 ◽

2012 ◽

Vol 5 (9) ◽

pp. 890-898 ◽

Cited By ~ 6

Author(s):

Xiangyi Lu ◽

Luan Wang ◽

Douglas M. Ruden

Keyword(s):

Drug Resistance ◽

Cancer Drug ◽

Hsp90 Inhibitors ◽

Cancer Drug Resistance ◽

Anti Cancer ◽

Genetic Mechanisms

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FAM129B is a novel regulator of Wnt/β-catenin signal transduction in melanoma cells

F1000Research ◽

10.12688/f1000research.2-134.v1 ◽

2013 ◽

Vol 2 ◽

pp. 134 ◽

Cited By ~ 1

Author(s):

Willliam Conrad ◽

Michael B Major ◽

Michele A Cleary ◽

Marc Ferrer ◽

Brian Roberts ◽

...

Keyword(s):

Large Scale ◽

Target Gene ◽

Mapk Pathway ◽

Melanoma Cells ◽

Luciferase Reporter ◽

Braf Inhibitors ◽

Sirna Screen ◽

Reporter Activity ◽

Fibrosarcoma Cells ◽

Interfering Rna

The inability of targeted BRAF inhibitors to produce long-lasting improvement in the clinical outcome of melanoma highlights a need to identify additional approaches to inhibit melanoma growth. Recent studies have shown that activation of the Wnt/β-catenin pathway decreases tumor growth and cooperates with ERK/MAPK pathway inhibitors to promote apoptosis in melanoma. Therefore, the identification of Wnt/β-catenin regulators may advance the development of new approaches to treat this disease. In order to move towards this goal we performed a large scale small-interfering RNA (siRNA) screen for regulators of β-catenin activated reporter activity in human HT1080 fibrosarcoma cells. Integrating large scale siRNA screen data with phosphoproteomic data and bioinformatics enrichment identified a protein, FAM129B, as a potential regulator of Wnt/β-catenin signaling. Functionally, we demonstrated that siRNA-mediated knockdown of FAM129B in A375 and A2058 melanoma cell lines inhibits WNT3A-mediated activation of a β-catenin-responsive luciferase reporter and inhibits expression of the endogenous Wnt/β-catenin target gene, AXIN2. We also demonstrate that FAM129B knockdown inhibits apoptosis in melanoma cells treated with WNT3A. These experiments support a role for FAM129B in linking Wnt/β-catenin signaling to apoptosis in melanoma.

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Replication gaps are a cancer vulnerability counteracted by translesion synthesis

10.1101/781997 ◽

2019 ◽

Author(s):

Sumeet Nayak ◽

Jennifer A. Calvo ◽

Ke Cong ◽

Emily Berthiaume ◽

Jessica Jackson ◽

...

Keyword(s):

Electron Microscopy ◽

Dna Damage ◽

Stress Response ◽

Cancer Cell ◽

Replication Fork ◽

Translesion Synthesis ◽

Cancer Therapies ◽

Fiber Analysis ◽

Molecule Inhibitor ◽

Anti Cancer

SUMMARYThe replication stress response which serves as an anti-cancer barrier is activated not only by DNA damage and replication obstacles, but also oncogenes, mystifying how cancer evolves. Here, we identify that oncogene expression, similar to cancer therapies, induces single stranded DNA (ssDNA) gaps that reduce cell fitness, unless suppressed by translesion synthesis (TLS). DNA fiber analysis and electron microscopy reveal that TLS restricts replication fork slowing, reversal, and fork degradation without inducing replication fork gaps. Evidence that TLS gap suppression is fundamental to cancer, a small molecule inhibitor targeting the TLS factor, REV1, not only disrupts DNA replication and cancer cell fitness, but also synergizes with gap-inducing therapies. This work illuminates that gap suppression during replication is critical for cancer cell fitness and therefore a targetable vulnerability.

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The Role of Cancer Stem Cells in Drug Resistance in Gastroesophageal Junction Adenocarcinoma

Frontiers in Molecular Biosciences ◽

10.3389/fmolb.2021.600373 ◽

2021 ◽

Vol 8 ◽

Author(s):

Kate Dinneen ◽

Anne-Marie Baird ◽

Ciara Ryan ◽

Orla Sheils

Keyword(s):

Stem Cells ◽

Drug Resistance ◽

Cancer Stem Cells ◽

Current Knowledge ◽

Gastroesophageal Junction ◽

Western World ◽

Specific Cell ◽

Cancer Therapies ◽

Mesenchymal Transition ◽

Anti Cancer

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.

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

PeerJ ◽

10.7717/peerj.12338 ◽

2021 ◽

Vol 9 ◽

pp. e12338

Author(s):

Yeelon Yeoh ◽

Teck Yew Low ◽

Nadiah Abu ◽

Pey Yee Lee

Keyword(s):

Colorectal Cancer ◽

Drug Resistance ◽

Abc Transporters ◽

Advanced Colorectal Cancer ◽

Drug Efflux ◽

Cancer Therapies ◽

Cancer Treatments ◽

Anti Cancer ◽

Notch Pathways ◽

Spectrum Of Patients

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.

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DNA Repair Pathways in Cancer Therapy and Resistance

Frontiers in Pharmacology ◽

10.3389/fphar.2020.629266 ◽

2021 ◽

Vol 11 ◽

Author(s):

Lan-ya Li ◽

Yi-di Guan ◽

Xi-sha Chen ◽

Jin-ming Yang ◽

Yan Cheng

Keyword(s):

Dna Damage ◽

Dna Repair ◽

Mammalian Cells ◽

Chemotherapeutic Agents ◽

Cancer Therapies ◽

Exogenous Dna ◽

Dna Damaging Agents ◽

Anti Cancer ◽

Mitochondria Dna ◽

Repair Pathways

DNA repair pathways are triggered to maintain genetic stability and integrity when mammalian cells are exposed to endogenous or exogenous DNA-damaging agents. The deregulation of DNA repair pathways is associated with the initiation and progression of cancer. As the primary anti-cancer therapies, ionizing radiation and chemotherapeutic agents induce cell death by directly or indirectly causing DNA damage, dysregulation of the DNA damage response may contribute to hypersensitivity or resistance of cancer cells to genotoxic agents and targeting DNA repair pathway can increase the tumor sensitivity to cancer therapies. Therefore, targeting DNA repair pathways may be a potential therapeutic approach for cancer treatment. A better understanding of the biology and the regulatory mechanisms of DNA repair pathways has the potential to facilitate the development of inhibitors of nuclear and mitochondria DNA repair pathways for enhancing anticancer effect of DNA damage-based therapy.

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A Triple Co-Delivery Liposomal Carrier That Enhances Apoptosis via an Intrinsic Pathway in Melanoma Cells

Cancers ◽

10.3390/cancers11121982 ◽

2019 ◽

Vol 11 (12) ◽

pp. 1982 ◽

Cited By ~ 4

Author(s):

Nina Filipczak ◽

Anna Jaromin ◽

Adriana Piwoni ◽

Mohamed Mahmud ◽

Can Sarisozen ◽

...

Keyword(s):

Cancer Cells ◽

Melanoma Cells ◽

Mitochondrial Pathway ◽

Cytotoxic Action ◽

Cancer Therapies ◽

Normal Cells ◽

Freeze And Thaw ◽

Anti Cancer ◽

Remote Loading ◽

Activity Mechanism

The effectiveness of existing anti-cancer therapies is based mainly on the stimulation of apoptosis of cancer cells. Most of the existing therapies are somewhat toxic to normal cells. Therefore, the quest for nontoxic, cancer-specific therapies remains. We have demonstrated the ability of liposomes containing anacardic acid, mitoxantrone and ammonium ascorbate to induce the mitochondrial pathway of apoptosis via reactive oxygen species (ROS) production by the killing of cancer cells in monolayer culture and shown its specificity towards melanoma cells. Liposomes were prepared by a lipid hydration, freeze-and-thaw (FAT) procedure and extrusion through polycarbonate filters, a remote loading method was used for dug encapsulation. Following characterization, hemolytic activity, cytotoxicity and apoptosis inducing effects of loaded nanoparticles were investigated. To identify the anticancer activity mechanism of these liposomes, ROS level and caspase 9 activity were measured by fluorescence and by chemiluminescence respectively. We have demonstrated that the developed liposomal formulations produced a high ROS level, enhanced apoptosis and cell death in melanoma cells, but not in normal cells. The proposed mechanism of the cytotoxic action of these liposomes involved specific generation of free radicals by the iron ions mechanism.

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The Influence of Tumor Microenvironment on Immune Escape of Melanoma

International Journal of Molecular Sciences ◽

10.3390/ijms21218359 ◽

2020 ◽

Vol 21 (21) ◽

pp. 8359 ◽

Cited By ~ 4

Author(s):

Aleksandra Simiczyjew ◽

Ewelina Dratkiewicz ◽

Justyna Mazurkiewicz ◽

Marcin Ziętek ◽

Rafał Matkowski ◽

...

Keyword(s):

Tumor Microenvironment ◽

Immune Escape ◽

Cell Types ◽

Melanoma Cells ◽

Cancer Therapies ◽

System A ◽

Anti Cancer ◽

Low Efficiency ◽

Inflammatory Molecules

The low efficiency of currently-used anti-cancer therapies poses a serious challenge, especially in the case of malignant melanoma, a cancer characterized by elevated invasiveness and relatively high mortality rate. The role of the tumor microenvironment in the progression of melanoma and its acquisition of resistance to treatment seems to be the main focus of recent studies. One of the factors that, in normal conditions, aids the organism in its fight against the cancer and, following the malignant transformation, adapts to facilitate the development of the tumor is the immune system. A variety of cell types, i.e., T and B lymphocytes, macrophages, and dendritic and natural killer cells, as well as neutrophils, support the growth and invasiveness of melanoma cells, utilizing a plethora of mechanisms, including secretion of pro-inflammatory molecules, induction of inhibitory receptors expression, or depletion of essential nutrients. This review provides a comprehensive summary of the processes regulated by tumor-associated cells that promote the immune escape of melanoma cells. The described mechanisms offer potential new targets for anti-cancer treatment and should be further studied to improve currently-employed therapies.

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