Cancer Therapeutic Resistance Research Articles

Mitochondria in cancer stem cells: Achilles heel or hard armor.

Previous studies have shown that mitochondria play core roles in not only cancer stem cell (CSC) metabolism but also the regulation of CSC stemness maintenance and differentiation, which are key regulators of cancer progression and therapeutic resistance. Therefore, an in-depth study of the regulatory mechanism of mitochondria in CSCs is expected to provide a new target for cancer therapy. This article mainly introduces the roles played by mitochondria and related mechanisms in CSC stemness maintenance, metabolic transformation, and chemoresistance. The discussion mainly focuses on the following aspects: mitochondrial morphological structure, subcellular localization, mitochondrial DNA, mitochondrial metabolism, and mitophagy. The manuscript also describes the recent clinical research progress on mitochondria-targeted drugs and discusses the basic principles of their targeted strategies. Indeed, an understanding of the application of mitochondria in the regulation of CSCs will promote the development of novel CSC-targeted strategies, thereby significantly improving the long-term survival rate of patients with cancer.

Targeting oncogenic KRAS in non-small cell lung cancer with EGFR aptamer-conjugated multifunctional RNA nanoparticles

KRAS mutations are one of the most common oncogenic driver mutations in human cancers, including non-small cell lung cancer (NSCLC), and have established roles in cancer pathogenesis and therapeutic resistance. The development of effective inhibitors of mutant KRAS represents a significant challenge. Three-way junction (3WJ)-based multi-functional RNA nanoparticles have the potential to serve as an effective invivo siRNA delivery platform with the ability to enhance tumor targeting specificity and visualize biodistribution through an imaging moiety. Herein, we assembled novel EGFRapt-3WJ-siKRASG12C mutation targeted nanoparticles to target EGFR-expressing human NSCLC harboring a KRASG12C mutation to silence KRASG12C expression in a tumor cell-specific fashion. We found that EGFRapt-3WJ-siKRASG12Cnanoparticles potently depleted cellular KRASG12C expression, resulting in attenuation of downstream MAPK pathway signaling, cell proliferation, migration/invasion ability, and sensitized NSCLC cells to chemoradiotherapy. Invivo, these nanoparticles induced tumor growth inhibition in KRASG12C NSCLC tumor xenografts. Together, this study suggests that the 3WJ pRNA-based platform has the potential to suppress mutant KRAS activity for the treatment of KRAS-driven human cancers, and warrants further development for clinical translation.

Mechanisms underlying response and resistance to immune checkpoint blockade in cancer immunotherapy.

Cancer immunotherapies targeting immune checkpoint pathways, such as programmed cell death-1 (PD-1)/programmed cell death ligand-1 (PD-L1) and cytotoxic T-lymphocyte-associated antigen-4 (CTLA-4), have achieved unprecedented therapeutic success in treating various types of cancer. The prominent and persistent clinical responses to immune checkpoint blockade (ICB) therapy are currently constrained to a subset of patients. Owing to discrete individual tumor and immune heterogeneity, most patients fail to benefit from ICB treatment, demonstrating either primary or acquired resistance. A thorough comprehension of the mechanisms restricting the efficacy of immune checkpoint inhibitors (ICIs) is required to extend their clinical applicability to a broader spectrum of patients and cancer types. Numerous studies are presently investigating potential prognostic markers of responsiveness, the complex dynamics underlying the therapeutic and adverse effects of ICB, and tumor immune evasion throughout the course of immunotherapy. In this article, we have reviewed the extant literature elucidating the mechanisms underlying the response and resistance to ICB, with a particular emphasis on PD-1 and CTLA-4 pathway blockade in the context of anti-tumor immunity. Furthermore, we aimed to explore potential approaches to overcome cancer therapeutic resistance and develop a rational design for more personalized ICB-based combinational regimens.

HMGB1, a potential regulator of tumor microenvironment in KSHV-infected endothelial cells.

High-mobility group box 1 (HMGB1) is a protein that binds to DNA and participates in various cellular processes, including DNA repair, transcription, and inflammation. It is also associated with cancer progression and therapeutic resistance. Despite its known role in promoting tumor growth and immune evasion in the tumor microenvironment, the contribution of HMGB1 to the development of Kaposi's sarcoma (KS) is not well understood. We investigated the effect of HMGB1 on KS pathogenesis using immortalized human endothelial cells infected with Kaposi's sarcoma-associated human herpes virus (KSHV). Our results showed that a higher amount of HMGB1 was detected in the supernatant of KSHV-infected cells compared to that of mock-infected cells, indicating that KSHV infection induced the secretion of HMGB1 in human endothelial cells. By generating HMGB1 knockout clones from immortalized human endothelial cells using CRISPR/Cas9, we elucidated the role of HMGB1 in KSHV-infected endothelial cells. Our findings indicate that the absence of HMGB1 did not induce lytic replication in KSHV-infected cells, but the cell viability of KSHV-infected cells was decreased in both 2D and 3D cultures. Through the antibody array for cytokines and growth factors, CXCL5, PDGF-AA, G-CSF, Emmprin, IL-17A, and VEGF were found to be suppressed in HMGB1 KO KSHV-infected cells compared to the KSHV-infected wild-type control. Mechanistically, phosphorylation of p38 would be associated with transcriptional regulation of CXCL5, PDGF-A and VEGF. These observations suggest that HMGB1 may play a critical role in KS pathogenesis by regulating cytokine and growth factor secretion and emphasize its potential as a therapeutic target for KS by modulating the tumor microenvironment.

Targeting Myc-driven stress addiction in colorectal cancer

MYC is a proto-oncogene that encodes a powerful regulator of transcription and cellular programs essential for normal development, as well as the growth and survival of various types of cancer cells. MYC rearrangement and amplification is a common cause of hematologic malignancies. In epithelial cancers such as colorectal cancer, genetic alterations in MYC are rare. Activation of Wnt, ERK/MAPK, and PI3K/mTOR pathways dramatically increases Myc levels through enhanced transcription, translation, and protein stability. Elevated Myc promotes stress adaptation, metabolic reprogramming, and immune evasion to drive cancer development and therapeutic resistance through broad changes in transcriptional and translational landscapes. Despite intense interest and effort, Myc remains a difficult drug target. Deregulation of Myc and its targets has profound effects that vary depending on the type of cancer and the context. Here, we summarize recent advances in the mechanistic understanding of Myc-driven oncogenesis centered around mRNA translation and proteostress. Promising strategies and agents under development to target Myc are also discussed with a focus on colorectal cancer.

Stromal cell-derived small extracellular vesicles enhance radioresistance of prostate cancer cells via interleukin-8-induced autophagy.

Radiation is a curative treatment for localized prostate cancer (PCa). Unfortunately, radiotherapeutic efficacy is often diminished when patients develop more aggressive or metastatic phenotypes. Recent studies have demonstrated that extracellular vesicles participate in cancer therapeutic resistance by delivering small bioactive molecules, such as small non-coding RNAs. Here, we show that stromal cell-derived small extracellular vesicles (sEVs) facilitate the radioresistance of PCa cells by transporting interleukin-8 (IL-8). Indeed, prostatic stromal cells secrete more IL-8 than AR-positive PCa cells, which can be accumulated in sEVs. Intriguingly, the uptake of stromal cells-derived sEVs by radiosensitive PCa cells enhanced their radioresistance, which could be attenuated by silencing CXCL8 in stromal cells or inhibiting its receptor CXCR2 in PCa cells. sEV-mediated radioresistance has been validated in zebrafish and mouse xenograft tumours. Mechanistically, the uptake of stromal sEVs triggers the AMPK-activated autophagy pathway in PCa cells under the irradiation condition. Consequently, inactivating AMPK efficiently resensitized radiotherapy either by utilizing an AMPK inhibitor or silencing AMPKα in PCa cells. Furthermore, chloroquine (CQ), a lysosomal inhibitor, sufficiently resensitized radiotherapy via blockade of autophagolysosome fusion, leading to autophagosome accumulation in PC cells. Collectively, these results suggest that stromal cells enhance the radioresistance of PCa cells mainly through sEVs that deliver IL-8.

The effect of inhibition of receptor tyrosine kinase AXL on DNA damage response in ovarian cancer

AXL is a receptor tyrosine kinase that is often overexpressed in cancers. It contributes to pathophysiology in cancer progression and therapeutic resistance, making it an emerging therapeutic target. The first-in-class AXL inhibitor bemcentinib (R428/BGB324) has been granted fast track designation by the U.S. Food and Drug Administration (FDA) in STK11-mutated advanced metastatic non-small cell lung cancer and was also reported to show selective sensitivity towards ovarian cancers (OC) with a Mesenchymal molecular subtype. In this study, we further explored AXL’s role in mediating DNA damage responses by using OC as a disease model. AXL inhibition using R428 resulted in the increase of DNA damage with the concurrent upregulation of DNA damage response signalling molecules. Furthermore, AXL inhibition rendered cells more sensitive to the inhibition of ATR, a crucial mediator for replication stress. Combinatory use of AXL and ATR inhibitors showed additive effects in OC. Through SILAC co-immunoprecipitation mass spectrometry, we identified a novel binding partner of AXL, SAM68, whose loss in OC cells harboured phenotypes in DNA damage responses similar to AXL inhibition. In addition, AXL- and SAM68-deficiency or R428 treatment induced elevated levels of cholesterol and upregulated genes in the cholesterol biosynthesis pathway. There might be a protective role of cholesterol in shielding cancer cells against DNA damage induced by AXL inhibition or SMA68 deficiency.

A phase (Ph) I/II trial of abiraterone acetate in combination with tildrakizumab (anti-IL23 monoclonal antibody) in patients with metastatic castration-resistant prostate cancer (mCRPC).

TPS5105 Background: Tumor-infiltrating inflammatory myeloid cells promote prostate cancer (PC) growth and therapeutic resistance. Myeloid inflammatory cells release interleukin-23 (IL-23) to fuel tumor growth via JAK2-STAT3 signalling and facilitate tumor-promoting T helper 17 (TH17) differentiation in PC models in vivo. IL-23 blockade reverses resistance to AR-targeting in vivo; we hypothesise that targeting IL-23 can be an effective therapeutic strategy for CRPC. Tildrakizumab, an anti-IL-23 (p19) monoclonal antibody, is FDA/EMA approved for treating moderate-severe psoriasis. In progress is the first clinical trial to combining IL-23 and AR signalling blockade in humans. Methods: This is an open-label, single-arm, Ph 1/2, dose-escalation and expansion study evaluating safety and tolerability of tildrakizumab and abiraterone acetate combination therapy in patients with mCRPC. Eligible patients must have progressed on androgen deprivation therapy, plus abiraterone and/or enzalutamide. The Ph 1 trial will adopt a one-stage Bayesian Continual Reassessment Method design exploring escalating doses of 4-weekly, IV tildrakizumab (100 mg, 300 mg, and 600 mg), in combination with standard fixed doses of abiraterone acetate and methylprednisolone, with the aim of determining the maximum tolerated dose (MTD) and recommended phase 2 dose (RP2D). Depending on the number of responses observed, tolerable dose levels may be expanded up to 10 patients after review by the Safety Review Committee (SRC). The RP2D and MTD determination will be based on the rate of toxicity and efficacy, reviewed by the SRC. Once RP2D is determined, the Ph 2 study will enrol up to 25 response-evaluable patients using a Simon’s two-stage design. Primary endpoint of the Ph 2 trial is overall response rate. Adverse events are assessed according to CTCAE v5. Tumor response is determined according to RECIST v1.1, confirmed PSA decline of at least 50%, and/or CTC conversion. PK analyses is being performed for both drugs to identify potential drug-drug interactions. PD analyses is being performed on archival and serial tumour biopsies and blood samples to investigate putative predictive biomarkers and confirm on-target and downstream effector modulation. The trial began enrolling in January 2021 in the United Kingdom and Switzerland. As of January 22th 2023, 12 patients were included in the study. Clinical trial information: NCT04458311 .

The role of miRNAs in laryngeal cancer pathogenesis and therapeutic resistance - A focus on signaling pathways interplay.

Laryngeal cancer (LC)is the malignancy of the larynx (voice box). The majority of LC are squamous cell carcinomas. Many risk factors were reported to be associated with LC as tobacco use, obesity, alcohol intake, human papillomavirus (HPV) infection, and asbestos exposure. Besides, epigenetics as non-coding nucleic acids also have a great role in LC. miRNAs are short nucleic acid molecules that can modulate multiple cellular processes by regulating the expression of their genes. Therefore, LC progression, apoptosis evasions, initiation, EMT, and angiogenesis are associated with dysregulated miRNA expressions. miRNAs also could have some vital signaling pathways such as mTOR/P-gp, Wnt/-catenin signaling, JAK/STAT, KRAS, and EGF. Besides, miRNAs also have a role in the modulation of LC response to different therapeutic modalities. In this review, we have provided a comprehensive and updated overview highlighting the microRNAs biogenesis, general biological functions, regulatory mechanisms, and signaling dysfunction in LC carcinogenesis, in addition to their clinical potential for LC diagnosis, prognosis, and chemotherapeutics response implications.

ADAR1 polymorphisms contribute to increased susceptibility in pediatric acute lymphoblastic leukemia.

Adenosine deaminase acting on RNA1 (ADAR1), catalyzing post-transcriptional adenosine-to-inosine RNA editing, promotes cancer progression and therapeutic resistance. However, very little is known about the association of ADAR1 variants with acute lymphoblastic leukemia (ALL). Here we first explored the potential association of three polymorphisms (rs9616, rs2229857, and rs1127313) of ADAR1 with susceptibility in Chinese children ALL, then functionally characterized ADAR1 in ALL. Our results demonstrated that rs9616 T and rs2229857 T were associated with increased expression of ADAR1 mRNA and higher risk to ALL. Of note, a stronger risk effect of rs2229857 T genotypes was found among relapse children. Furthermore, ADAR1 knockdown specifically inhibited proliferation and promoted apoptosis in ALL cells. These findings give insights into a mechanism by which the risk variant at rs9616 and rs2229857 modulate ADAR1 expression and confers a predisposition and relapse risk to ALL, and representing a potential novel biomarker for pediatric ALL.

Collagen I-DDR1 signaling promotes hepatocellular carcinoma cell stemness via Hippo signaling repression.

Cancer stem cells (CSCs) are a minority population of cancer cells with stemness and multiple differentiation potentials, leading to cancer progression and therapeutic resistance. However, the concrete mechanism of CSCs in hepatocellular carcinoma (HCC) remains obscure. We found that in advanced HCC tissues, collagen I was upregulated, which is consistent with the expression of its receptor DDR1. Accordingly, high collagen I levels accompanied by high DDR1 expression are associated with poor prognoses in patients with HCC. Collagen I-induced DDR1 activation enhanced HCC cell stemness in vitro and in vivo. Mechanistically, DDR1 interacts with CD44, which acts as a co-receptor that amplifies collagen I-induced DDR1 signaling, and collagen I-DDR1 signaling antagonized Hippo signaling by facilitating the recruitment of PP2AA to MST1, leading to exaggerated YAP activation. The combined inhibition of DDR1 and YAP synergistically abrogated HCC cell stemness in vitro and tumorigenesis in vivo. A radiomic model based on T2 weighted images can noninvasively predict collagen I expression. These findings reveal the molecular basis of collagen I-DDR1 signaling inhibiting Hippo signaling and highlight the role of CD44/DDR1/YAP axis in promoting cancer cell stemness, suggesting that DDR1 and YAP may serve as novel prognostic biomarkers and therapeutic targets in HCC.

Abstract LB061: Proteomic-based stemness score measure oncogenic dedifferentiation and enable the identification of druggable targets

Abstract Progression and therapeutic resistance in cancer have been strongly associated with the acquisition of a stemness phenotype. Here, we provide new stemness indices for assessing the degree of oncogenic dedifferentiation in tumor samples. We used a machine learning model to predict the stemness molecular phenotype based on proteomic data. The prediction model was built from human pluripotent stem cell from the Human Induced Pluripotent Stem Cells Consortium (HipSci) and applied to compute stemness indices on the Clinical Proteomic Tumor Analysis Consortium (CPTAC) tumor samples, consisting in their proteogenomic hallmarks of stemness. The obtained stemness scores based on protein expression are novel and original, and are significantly more robust compared to our previous published work. The obtained proteomic score is able to classify stem cells and non-stem cell classes. The initial analysis of over 2000 tumor samples obtained from twelve types of primary carcinomas of breast, ovary, lung, kidney, uterus, brain (pediatric and adult), head and neck, liver, stomach, colon, and pancreas has confirmed our previously published results. Indexing of CPTAC tumors with proteomic stemness score brought us with previously unappreciated findings. We integrated the stemness scores computed using proteins with gene expression, DNA methylation, microRNA, copy number alteration and protein post-translational modification to identify coherent proteogenomic stemness association. Our initial findings identified proteins and phospho-proteins as active nodes of signaling pathways and transcriptional networks that drive aggressiveness of the primary tumors that cause resistance to existing therapies. The correlation between stemness scores and protein expression resulted in the identification of potential drug targets for anti-cancer therapy both tumor-specific and shared among different tumor types. Our results also revealed stemness-associated proteins predictive of clinical outcome across analyzed tumor types. Finally, we validated some stemness targets by immunohistochemistry in independent samples and confirmed the association with clinical outcome. Targeting the proteins here identified and cellular mechanisms that drive a stemness phenotype with existing or novel drugs may eventually lead for clinical development of effective cures for cancer patients. Citation Format: Tathiane M. Malta, Iga Kołodziejczak, Renan Simões, Antonio Colaprico, Erik Storrs, Francesca Petralia, Felipe da v Leprevost, Rossana L. Segura, Elizabeth Demicco, Alexander J. Lazar, Weiping Ma, Pietro Pugliese, Michele Ceccarelli, Bozena Kamińska, Alexey I. Nesvizhski, Bing Zhang, Henry Rodriguez, Mehdi Mesri, Ana I. Robles, Clinical Proteomic Tumor Analysis Consortium, Li Ding, Maciej Wiznerowicz. Proteomic-based stemness score measure oncogenic dedifferentiation and enable the identification of druggable targets [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 2 (Clinical Trials and Late-Breaking Research); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(8_Suppl):Abstract nr LB061.

Abstract 4807: BACH1 proline hydroxylation regulates the hypoxia response and metastasis in triple negative breast cancer

Abstract Hypoxia is an important hallmark of aggressive solid tumors. Here we show that the pro-metastatic BTB and CNC homology 1 (BACH1) transcription factor is prolyl-hydroxylated by the HIF Prolyl Hydroxylase 1 (PHD1) in an oxygen-dependent manner. Using mass spectrometry, we identified two major prolyl hydroxylation sites in BACH1 and demonstrate that prolyl hydroxylation increased protein turnover in normoxia. Notably, a clinically relevant BACH1 mutant (BACH1M) resistant to hydroxylation displays enhanced BACH1 DNA binding capacity. Triple-negative breast cancer (TNBC) cells expressing BACH1M showed higher invasion in vitro and increased metastasis in vivo. Loss of BACH1 reduced the cellular transcriptional hypoxic response. Under hypoxia, BACH1 increases chromatin accessibility and gene expression through chromatin remodeling involving direct BACH1 binding and indirect epigenetic regulation. These results indicate that hypoxia stabilizes and enhances the pro-metastatic transcriptional activity of BACH1 through loss of prolyl hydoxylation in TNBC. Our findings identify BACH1 as an oxygen sensitive effector of the hypoxia response and a clinically relevant target for attenuating hypoxia induced, pro-metastatic signaling and therapeutic resistance in cancers. Citation Format: Long Chi Nguyen, Christopher Dann, Dongbo Yang, Emily Shi, Thomas Li, Joseph Wynne, Letícia Stock, Madeline Henn, Zeyu Qiao, Andrea Valdespino, Raven Watson, Wenchao Liu, Lydia Robinson-Mailman, Galina Khramtsova, Mitsuyo Matsumoto, Raymond Moellering, Olufunmilayo I. Olopade, Kazuhiko Igarashi, Marsha R. Rosner. BACH1 proline hydroxylation regulates the hypoxia response and metastasis in triple negative breast cancer. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 4807.

Abstract 4829: Monitoring metabolic plasticity in the tumor microenvironment in vivo

Abstract Tumor metabolic reprogramming is a hallmark of cancer progression, survival, and therapeutic resistance. A targetable class of cancer metabolic adaptation exploits mitophagy, a specialized autophagy pathway known to be linked to the cancer phenotype. Mitophagy selectively eliminates dysfunctional mitochondria by targeting them, via autophagosome shuttling, to the lysosome for degradation. Cancer cell mitophagy is triggered by elevated oxidative stress and mitochondria DNA damage caused by hypoxia, radiotherapy, molecular therapy, and immunotherapy. A high mitophagy demand can overwhelm the lysosome capacity resulting in the accumulation of damaged mitochondria that is harmful to the cell, and can suppress biogenesis of healthy mitochondria. We hypothesize that the newly discovered process of secretory mitophagy exports damaged mitochondrial fission-released segments to reduce the overload pressure on the lysosomal system, and thereby sustains cancer cell survival in the face of therapeutic mitochondrial stress. We have discovered a form of secretory mitophagy occurring in vivo in a growing solid tumor. Our molecular analysis of the full repertoire of extracellular vesicles (EV) shed into the resident tumor interstitial fluid (IF) in vivo yielded a rich set of information about the functional state of mitochondria within the tumor cells, and the host cells. A set of proteins required for sequential steps of fission-induced mitophagy preferentially populated the CD81+/PD-L1+ IF EVs; including PINK1 and ARIH1 E3 ubiquitin ligase (required for Parkin-independent mitophagy), DRP1 and FIS1 (mitochondrial pinching), VDAC-1 (ubiquitination state triggers mitophagy away from apoptosis), and VPS35, SEC22b, and Rab33b (vacuolar sorting). Comparing in vivo IF EVs to in vitro EVs revealed 40% concordance, with an elevation of mitophagy proteins in the CD81+ EVs for both murine and human cell lines subjected to metabolic stress. The export of cellular mitochondria proteins to CD81+ EVs was confirmed by density gradient isolation from the bulk EV isolate followed by anti-CD81 immunoprecipitation, MitoTracker export into CD81+ EVs, and ultrastructural characterization. Further, we stimulated mitochondrial oxidative stress and blocked the fusion of the mitophagosome with the lysosome, which markedly stimulated the export of the secretory mitophagy unit. We also found that mitophagy inducer PINK1 cleavage status (full length versus cleaved), is prominently reflected in the set of mitochondrial proteins exported within IF EVs, and may constitute a new quantitative measurement tool to monitor the real-time state of tumor intracellular mitophagy. The outcome is new understanding of the importance of secretory mitophagy that can constitute an important therapeutic target, and a new clinically relevant means of monitoring the in vivo state of mitophagic flux within the tumor microenvironment. Citation Format: Marissa Ashton Howard. Monitoring metabolic plasticity in the tumor microenvironment in vivo. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 4829.

Agent-based methods facilitate integrative science in cancer.

In this opinion, we highlight agent-based modeling as a key tool for exploration of cell-cell and cell-environment interactions that drive cancer progression, therapeutic resistance, and metastasis. These biological phenomena are particularly suited to be captured at the cell-scale resolution possible only within agent-based or individual-based mathematical models. These modeling approaches complement experimental work (in vitro and in vivo systems) through parameterization and data extrapolation but also feed forward to drive new experiments that test model-generated predictions.

Hyperinsulinism Gateway Between Diabetes and Cancer: New Roles for Bifunctional Antidiabetic - Anticancer Active Somatostatins, IGF - 1 Inhibitors and Insulin Sensitizers

Hyperinsulinism refers to a condition of abnormally high concentration of circulating insulin in the body commonly seen in obese and type 2 diabetic patients due to insulin resistance. Elevated circulating insulin is the main factor linking obesity, diabetes and cancer and an important mechanism of cancer therapeutic resistance and failure. The insulin receptor subfamily which is made up of the insulin receptor (IR), the type 1 IGF receptor (IGF-1) which binds insulin-like growth factors I and II, and the orphan insulin receptor-related receptor (IRRR) have been identified and linked to the process of carcinogenesis, as cancer cells require insulin for growth. IR receptors are overexpressed in various cancers and insulin activates growth mostly through these receptors and their interplays through mainly the PI3K/AKT/mTOR, MAPK and RAS signal transduction pathways. Estrogens and androgens synergistic effects worsen hyperinsulinism and accelerates its carcinogenesis properties while progesterone and Sex Hormone Binding Globulins exert modulatory effects. This review examined the various factor interplays in hyperinsulinism that links diabetes with cancer and the biomarkers involved. It equally identified the potentials and therapeutic roles for Somatostatins, IGF – 1 inhibitors and Insulin sensitizing antidiabetics in preventing and reversing the cancer linked trends.

Bone marrow adipocytes induce cancer-associated fibroblasts and immune evasion, enhancing invasion and drug resistance.

Bone metastasis occurs frequently occurred in cancer patients. Conventional therapies have limited therapeutic outcomes, and thus, exploring the mechanisms of cancer progression in the bone metastasis is important to develop new effective therapies. In the bone microenvironment, adipocytes are the major stromal cells that interact with cancer cells during the bone metastasis. However, the comprehensive functions of bone marrow adipocytes in cancer progression are not yet fully understood. To address this, we investigated the role of bone marrow adipocytes on cancer cells, by focusing on an invasive front which reflects the direct effects of stromal cells on cancer. In comprehensive histopathological and genetic analysis using bone metastasis specimens, we examined invasive fronts in bone metastasis and compared invasive fronts with adipocyte-rich bone marrow (adipo-BM) to those with hematopoietic cell-rich bone marrow (hemato-BM) as a normal counterpart of adipocytes. We found morphological complexity of invasive front with adipo-BM was significantly higher than that with hemato-BM. Based on immunohistochemistry, the invasive front with adipo-BM comparatively had significantly increased cancer-associated fibroblasts (CAFs) marker-positive area and lower density of CD8 positive lymphocytes compared to that with hemato-BM. RNA-seq analysis of primary and bone metastasis cancer reveals that bone metastasized cancer cells acquired drug resistance related gene expression phenotypes. Clearly, these findings indicate that bone marrow adipocytes provide favorable tumor microenvironment for cancer invasion and therapeutic resistance of bone metastasized cancers via CAF induction and immune evasion, providing a potential target for the treatment of bone metastasis.

Dynamics of Epithelial-Mesenchymal Plasticity: What Have Single-Cell Investigations Elucidated So Far?

Epithelial-mesenchymal plasticity (EMP) is a key driver of cancer metastasis and therapeutic resistance, through which cancer cells can reversibly and dynamically alter their molecular and functional traits along the epithelial-mesenchymal spectrum. While cells in the epithelial phenotype are usually tightly adherent, less metastatic, and drug-sensitive, those in the hybrid epithelial/mesenchymal and/or mesenchymal state are more invasive, migratory, drug-resistant, and immune-evasive. Single-cell studies have emerged as a powerful tool in gaining new insights into the dynamics of EMP across various cancer types. Here, we review many recent studies that employ single-cell analysis techniques to better understand the dynamics of EMP in cancer both in vitro and in vivo. These single-cell studies have underlined the plurality of trajectories cells can traverse during EMP and the consequent heterogeneity of hybrid epithelial/mesenchymal phenotypes seen at both preclinical and clinical levels. They also demonstrate how diverse EMP trajectories may exhibit hysteretic behavior and how the rate of such cell-state transitions depends on the genetic/epigenetic background of recipient cells, as well as the dose and/or duration of EMP-inducing growth factors. Finally, we discuss the relationship between EMP and patient survival across many cancer types. We also present a next set of questions related to EMP that could benefit much from single-cell observations and pave the way to better tackle phenotypic switching and heterogeneity in clinic.

A ciprofloxacin derivative with four mechanisms of action overcomes paclitaxel resistance in p53-mutant and MDR1 gene-expressing type II human endometrial cancer

Dysfunction of the p53 gene and the presence of the MDR1 gene are associated with many malignant tumors including endometrial cancer and are responsible for cancer therapeutic resistance and poor survival. Thus, there is a critical need to devise novel combinatorial therapies with multiple mechanisms of action to overcome drug resistance. Here, we report a new ciprofloxacin derivative (CIP2b) tested either alone or in combination with taxanes against four human endometrial cancer cell lines. In vitro studies revealed that a combination of paclitaxel + CIP2b had synergistic cytotoxic effects against MDR1-expressing type-II human endometrial cancer cells with loss-of-function p53 (Hec50co LOFp53). Enhanced antitumor effects were confirmed by substantial increases in caspase-3 expression, cell population shifts toward the G2/M phase, and reduction of cdc2 phosphorylation. It was found that CIP2b targets multiple pathways including the inhibition of MDR1, topoisomerase I, and topoisomerase II, as well as enhancing the effects of paclitaxel (PTX) on microtubule assembly. In vivo treatment with the combination of PTX + CIP2b also led to significantly increased accumulation of PTX in tumors (compared to CIP2b alone) and reduction in tumor growth. Enhanced in vivo cytotoxic effects were confirmed by histological and immunohistochemical examination of the tumor tissues. Complete blood count and blood biochemistry data confirmed the absence of any apparent off-target toxicity. Thus, combination therapy involving PTX and CIP2b targeted multiple pathways and represents an approach that could result in improved tolerance and efficacy in patients with type-II endometrial cancer harboring the MDR1 gene and p53 mutations.

State-dependent evolutionary models reveal modes of solid tumour growth

Spatial properties of tumour growth have profound implications for cancer progression, therapeutic resistance and metastasis. Yet, how spatial position governs tumour cell division remains difficult to evaluate in clinical tumours. Here, we demonstrate that faster division on the tumour periphery leaves characteristic genetic patterns, which become evident when a phylogenetic tree is reconstructed from spatially sampled cells. Namely, rapidly dividing peripheral lineages branch more extensively and acquire more mutations than slower-dividing centre lineages. We develop a Bayesian state-dependent evolutionary phylodynamic model (SDevo) that quantifies these patterns to infer the differential division rates between peripheral and central cells. We demonstrate that this approach accurately infers spatially varying birth rates of simulated tumours across a range of growth conditions and sampling strategies. We then show that SDevo outperforms state-of-the-art, non-cancer multi-state phylodynamic methods that ignore differential sequence evolution. Finally, we apply SDevo to single-time-point, multi-region sequencing data from clinical hepatocellular carcinomas and find evidence of a three- to six-times-higher division rate on the tumour edge. With the increasing availability of high-resolution, multi-region sequencing, we anticipate that SDevo will be useful in interrogating spatial growth restrictions and could be extended to model non-spatial factors that influence tumour progression.