Tumor Reoccurrence Research Articles

The Regeneration of Intestinal Stem Cells Is Driven by miR-29-Induced Metabolic Reprogramming

Intestinal stem cells (ISCs) initiate intestinal epithelial regeneration and tumorigenesis, and they experience rapid refilling upon various injuries for epithelial repair as well as tumor reoccurrence. It is crucial to reveal the mechanism underlying such plasticity for intestinal health. Recent studies have found that metabolic pathways control stem cell fate in homeostasis, but the role of metabolism in the regeneration of ISCs after damage has not been clarified. Here, we find that in a human colorectal cancer dataset, miR-29a and b (miR-29a/b) are metabolic regulators highly associated with intestinal tumorigenesis and worse prognostic value of radiotherapy. We also show that these two microRNAs are required for intestinal stemness maintenance in mice, and their expression is induced in regenerated ISCs after irradiation injury, resulting in skewed ISC fate from differentiation towards self-renewal. This upregulation of miR-29a/b expression in ISCs leads to suppression of fatty acid oxidation (FAO) and depression of oxidative phosphorylation, which in turn controls the balance between self-renewal and differentiation of ISCs. Deletion of miR-29a/b prevents these effects and thus impairs ISC-mediated epithelial recovery. Finally, we filter the potential targets of miR-29a/b and identify Hnf4g, a transcription factor, that drives this metabolic reprogramming through regulating FAO-related enzymes. Our work discovers an important metabolic mechanism of ISC-mediated regeneration and potentially pave the way for more targeted and effective therapeutic strategies for intestinal repair as well as tumor treatment.

Unlocking the Therapeutic Potential of Oral Cancer Stem Cell-Derived Exosomes.

Oral cancer (OC) presents a significant global health burden with rising incidence rates. Despite advancements in diagnosis and treatments, the survival rate for OC patients, particularly those with advanced or recurrent disease, remains low at approximately 20%. This poor prognosis is often due to a small population of cancer stem cells (CSCs) that are capable of self-renewal and immune evasion, playing pivotal roles in proliferation, tumor initiation, progression, metastasis, and therapy resistance. Exosomes, which are nano-sized extracellular vesicles (EVs), have emerged as crucial mediators of cell-to-cell communication within the tumor microenvironment (TME). These vesicles carry diverse molecules such as DNA, RNA, proteins, lipids, and metabolites, influencing various cellular processes. Emerging evidence suggests that CSC-derived EVs significantly promote tumor progression and metastasis and maintain the balance between CSCs and non-CSCs, which is vital for intracellular communication within the TME of oral cancer. Recent reports indicate that oral cancer stem cell-derived EVs (OCSC-EVs) influence stemness, immune evasion, metastasis, angiogenesis, tumor reoccurrence, and drug resistance. Understanding OCSC-EVs could significantly improve oral cancer diagnosis, prognosis, and therapy. In this mini-review, we explore OCSC-derived exosomes in oral cancer, examining their potential as diagnostic and prognostic biomarkers that reflect CSC characteristics, and delve into their therapeutic implications, emphasizing their roles in tumor progression and therapy resistance. However, despite their promising potential, several challenges remain, including the need to standardize isolation and characterization methods and to elucidate exosome-mediated mechanisms. Thus, a comprehensive understanding of OCSC-EVs could pave the way for innovative therapeutic strategies that have the potential to improve clinical outcomes for OC patients.

A Review of Surgical Incisions Used for the Excision of Benign Parotid Tumors.

To provide surgical references for selecting appropriate parotidectomy incisions, reviewing modified approaches, incision designs, and associated complications. We have systematically searched 5 medical literature databases examining parotidectomy incision designs and postoperative complications from 2008 to 2021. There are a total of 9 novel incision designs: 1) posterior auricular hairline incision (PAHI); 2) combined preauricular and retroauricular incision (CPRI); 3) V-shaped incision (VI); 4) N-shaped incision (NI); 5) postaural incision (PI); 6) preauricular crutch incision (PCI); and 7) endaural incision (EI). Simultaneously, there are a total of 8 postoperative complications: 1) infection; 2) salivary fistula; 3) facial nerve palsy/paresis; 4) ear lobule numbness; 5) Frey syndrome; 6) facial deformity; 7) hematoma; and 8) tumor reoccurrence. Over the last decade, a surge in modified parotidectomy incisions has been witnessed in clinical practice. This expansion is attributed to rapid technical advancements and a deeper understanding of anatomy and histopathology. These modified approaches contribute significantly to improving cosmetic outcomes, minimizing associated complications, and enhancing patient satisfaction.

Endowing Pt(IV) with Perfluorocarbon Chains and Human Serum Albumin Encapsulation for Highly Effective Antitumor Chemoimmunotherapy.

Tumor metastases and reoccurrence are considered the leading causes of cancer-associated deaths. As an emerging therapeutic method, increasing research efforts have been devoted to immunogenic cell death (ICD)-inducing compounds to solve the challenge. The clinically approved chemotherapeutic Pt complexes are not or are only poorly able to trigger ICD. Herein, the axial functionalization of the Pt(II) complex cisplatin with perfluorocarbon chains into ICD-inducing Pt(IV) prodrugs is reported. Strikingly, while the Pt(II) complex as well as the perfluorocarbon ligands did not induce ICD, the Pt(IV) prodrug demonstrated unexpectantly the induction of ICD through accumulation in the endoplasmic reticulum and generation of reactive oxygen species in this organelle. To enhance the pharmacological properties, the compound was encapsulated with human serum albumin into nanoparticles. While selectively accumulating in the tumorous tissue, the nanoparticles demonstrated a strong tumor growth inhibitory effect against osteosarcoma inside a mouse model. In vivo tumor vaccine analysis also demonstrated the ability of Pt(IV) to be an ideal ICD inducer. Overall, this study reports on axially perfluorocarbon chain-modified Pt(IV) complexes for ICD induction and chemoimmunotherapy in osteosarcoma.

Using photodynamic approaches to improve the diagnostic accuracy of image guided surgery

SignificanceIncomplete surgical resection of tumors using white light and preoperative imaging causes tumor reoccurrence. Antibody-dye conjugate can target and accumulate into the tumor but has longer wait times for surgery following administration. This process can be expedited using PDP which not only increase the delivery but also improves the diagnostic accuracy in tumor detection. ApproachThe mice bearing FaDu head and neck tumors were administered with Cetuximab-IRDye800 (Cet-IRDye800) and treated with sub-therapeutic dose of PDT (photodynamic Priming; PDP). The accumulation and distribution of Cet-IRDye800 into the tumor were measured and analyzed. ResultsPDP improves and expedites the delivery of Cet-IRDye800 into the tumors significantly. It also improves diagnostic accuracy in tumor detection with respect to the vicinal salivary gland. ConclusionsThis study highlights, for the first time, that PDP enhances the rate and extend of delivery of the fluorescently labeled antibodies for the effective photodynamic image guided surgery.

Abstract 2019: Primary cancer associated fibroblasts increase the chemoresistance of triple negative breast cancer cells by mitochondria metabolic upregulation

Abstract Breast cancers (BCs) are the most prevalent cancers occurring in women. Tumor reoccurrence attributed to chemotherapy resistance remains a main challenge in fighting disease relapse. Cancer associated fibroblasts (CAFs) are the most prominent component of the tumor microenvironment (TME) and have already been implicated in therapy resistances. Although the exact molecular mechanisms behind this resistance remain unclear. In this regard, we recently identified 4 CAF populations (S1-S4) in ovarian and BCs, and showed that only CAF-S1 promote immunotherapy resistance as well as metastasis. Based on these observations, we are now investigating the impact of CAF-S1 on the chemotherapy response of BCs. To study the interactions between CAF-S1 and BC cells, we developed a tumor on chip (ToC) device, mimicking the TME in 3D. Using ToC live imaging, we show that primary CAF-S1 mediate a chemoprotective effect over luminal and triple negative BC (TNBC) cells by significantly decreasing their apoptosis rate as early as 10h after Doxorubicin and 40h after Paclitaxel treatment. Interestingly, CAF-S1 display a highly heterogenous response to Doxorubicin, allowing the classification into chemo-sensitive and -resistant CAF-S1. Regardless of premature CAF-S1 cell death, the chemoprotective effect over BC cells is maintained for at least 3 days. This indicates a crucial CAF-S1 - cancer cell cross talk at early timepoints. Additionally, by applying machine learning algorithms on live imaging videos, we demonstrate that physical proximity of CAF-S1 to BC cells immediately after treatment initiation correlates with BC cell survival, even after several days of treatment. This again implies cancer cell priming by CAF-S1 as a possible mechanism of chemotherapy resistance. To investigate this molecular interplay further, we performed scRNA-seq of ToC extracted and treatment naïve CAF-S1 and TNBC cells as well as bulk RNA-seq of patient derived TNBC tumors before/after chemotherapy treatment. We identify mitochondrial metabolic pathways to be upregulated in TNBC cells after CAF-S1 co-culture inside ToC devices and in TNBC cells of chemo-resistant patients enriched in CAF-S1 at baseline. We are now validating the impact of target gene knock downs on the survival of TNBC cells in CAF-S1 co-cultures after chemotherapy treatment on chip. Overall, these results provide insights into molecular mechanisms by which CAF-S1 promote chemotherapy resistance of breast cancers. Citation Format: Isabella Hofer, Arianna Mencattini, Yann Kieffer, Eugenio Martinelli, Maria Carla Parrini, Fatima Mechta-Grigoriou. Primary cancer associated fibroblasts increase the chemoresistance of triple negative breast cancer cells by mitochondria metabolic upregulation [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 2019.

P160 nuclear receptor coactivator family members and their role in rare fusion‑driven neoplasms (Review).

Gene fusions with translocations involving nuclear receptor coactivators (NCoAs) are relatively common among fusion-driven malignancies. NCoAs are essential mediators of environmental cues and can modulate the transcription of downstream target genes upon binding to activated nuclear receptors. Therefore, fusion proteins containing NCoAs can become strong oncogenic drivers, affecting the cell transcriptional profile. These tumors show a strong dependency on the fusion oncogene; therefore, the direct pharmacological targeting of the fusion protein becomes an attractive strategy for therapy. Currently, different combinations of chemotherapy regimens are used to treat a variety of NCoA-fusion-driven tumors, but given the frequent tumor reoccurrence, more efficient treatment strategies are needed. Specific approaches directed towards inhibition or silencing of the fusion gene need to be developed while minimizing the interference with the original genes. This review highlights the relevant literature describing the normal function and structure of NCoAs and their oncogenic activity in NCoA-gene fusion-driven cancers, and explores potential strategies that could be effective in targeting these fusions.

Surgical Primary Tumor Resection Reduces Accumulation of CD11b+ Myeloid Cells in the Lungs Augmenting the Efficacy of an Intranasal Cancer Vaccination against Secondary Lung Metastasis.

A hallmark of effective cancer treatment is the prevention of tumor reoccurrence and metastasis to distal organs, which are responsible for most cancer deaths. However, primary tumor resection is expected to be curative as most solid tumors have been shown both experimentally and clinically to accelerate metastasis to distal organs including the lungs. In this study, we evaluated the efficacy of our engineered nasal nano-vaccine (CpG-NP-Tag) in reducing accelerated lung metastasis resulting from primary tumor resection. Cytosine-phosphate-guanine oligonucleotide [CpG ODN]-conjugated nanoparticle [NP] encapsulating tumor antigen [Tag] (CpG-NP-Tag) was manufactured and tested in vivo using a syngeneic mouse mammary tumor model following intranasal delivery. We found that our nasal nano-vaccine (CpG-NP-Tag), compared to control NPs administered after primary mammary tumor resection, significantly reduced lung metastasis in female BALB/c mice subjected to surgery (surgery mice). An evaluation of vaccine efficacy in both surgery and non-surgery mice revealed that primary tumor resection reduces CD11b+ monocyte-derived suppressor-like cell accumulation in the lungs, allowing increased infiltration of vaccine-elicited T cells (IFN-γ CD8+ T cells) in the lungs of surgery mice compared to non-surgery mice. These findings suggest that the combination of the target delivery of a nasal vaccine in conjunction with the standard surgery of primary tumors is a plausible adjunctive treatment against the establishment of lung metastasis.

Herbal bioactive encapsulated nano-formulations for the treatment of gastric cancer: a concise review

Gastric cancer is a prominent cause of death globally. The major risk factors responsible for its development include age, H. pylori infection, excessive salt intake, and lack of fruits and vegetables in the diet. It is diagnosed using ultrasound, CT scan, endoscopic biopsy, and by detection of certain biomarkers. The conventional therapies for treatment of gastric cancer include the use of radiations, surgical resection, and chemotherapy. However, there are certain major issues associated with these treatments, like high risk of tumour reoccurrence, drug resistance development, less bioavailability of the drug at target site, rapid drug metabolism and high systemic toxicity due to drug doses. All such limitations of conventional treatments can be overcome with the use of herbal bio-actives as they exhibit less toxicity to normal healthy cells and reduce the risk of tumour recurrence and resistance development. Nano-formulations are developed to aid in targeted drug delivery, and to enhance the solubility, stability, bioavailability, and therapeutic efficacy of phytoconstituents. With the emergence of nanomaterials, different imaging modalities have been integrated into one single platform, and combined therapies with synergetic effects against gastric cancer were established. Moreover, the development of theragnostic strategies with simultaneous diagnostic and therapeutic ability was boosted by multifunctional nanoparticles. The present review discusses about the gastric cancer including its mortality rate, secular trends, pathophysiology, etiology, risk factors, diagnosis, and different treatment approaches with major emphasis on herbal bioactives (quercetin, paclitaxel, resveratrol, curcumin and ginsenosides) and different herbal constituent encapsulated nano-formulations (such as nanoparticles, niosomes, liposomes, nano-emulsion, and micelles). Challenges and future prospects of herbal bioactive encapsulated nano-formulations for the treatment/management of gastric cancers has been included in the later part of the manuscript.

Structure–function crosstalk in liver cancer research: Protein structuromics

Liver cancer can be primary (starting in the liver) or secondary (cancer that has spread from elsewhere to the liver, known as liver metastasis). Liver metastasis is more common than primary liver cancer. Despite great advances in molecular biology methods and treatments, liver cancer is still associated with a poor survival rate and a high death rate, and there is no cure. Many questions remain regarding the mechanisms of liver cancer occurrence and development as well as tumor reoccurrence after treatment. In this study, we assessed the protein structural features of 20 oncogenes and 20 anti-oncogenes via protein structure and dynamic analysis methods and 3D structural and systematic analyses of the structure–function relationships of proteins. Our aim was to provide new insights that may inform research on the development and treatment of liver cancer.

Steroid receptor coactivator 3 is a key modulator of regulatory T cell–mediated tumor evasion

Steroid receptor coactivator 3 (SRC-3) is most strongly expressed in regulatory T cells (Tregs) and B cells, suggesting that it plays an important role in the regulation of Treg function. Using an aggressive E0771 mouse breast cell line syngeneic immune-intact murine model, we observed that breast tumors were "permanently eradicated" in a genetically engineered tamoxifen-inducible Treg-cell-specific SRC-3 knockout (KO) female mouse that does not possess a systemic autoimmune pathological phenotype. A similar eradication of tumor was noted in a syngeneic model of prostate cancer. A subsequent injection of additional E0771 cancer cells into these mice showed continued resistance to tumor development without the need for tamoxifen induction to produce additional SRC-3 KO Tregs. SRC-3 KO Tregs were highly proliferative and preferentially infiltrated into breast tumors by activating the chemokine (C-C motif) ligand (Ccl) 19/Ccl21/chemokine (C-C motif) receptor (Ccr)7 signaling axis, generating antitumor immunity by enhancing the interferon-γ/C-X-C motif chemokine ligand (Cxcl) 9 signaling axis to facilitate the entrance and function of effector T cells and natural killer cells. SRC-3 KO Tregs also show a dominant effect by blocking the immune suppressive function of WT Tregs. Importantly, a single adoptive transfer of SRC-3 KO Tregs into wild-type E0771 tumor-bearing mice can completely abolish preestablished breast tumors by generating potent antitumor immunity with a durable effect that prevents tumor reoccurrence. Therefore, treatment with SRC-3-deleted Tregs represents an approach to completely block tumor growth and recurrence without the autoimmune side effects that typically accompany immune checkpoint modulators.

Enhancement of reactive oxygen species production in triple negative breast cancer cells treated with electric pulses and resveratrol.

Triple negative breast cancer (TNBC) is difficult to treat since it lacks all the three most commonly targeted hormone receptors. Patients afflicted with TNBC are treated with platinum core chemotherapeutics, such as cisplatin. Despite the initial effective anticancer effects of cisplatin, TNBC attenuates its effect and develops resistance eventually, which results in tumor reoccurrence. Hence, there is a critical demand for effective, alternative, and natural ways to treat TNBC. Towards this, a promising technique for inhibiting TNBC cell proliferation involves promoting the production of reactive oxygen species (ROS), which triggers pro-apoptotic caspases 9 and 3. Resveratrol (RESV), an active bio compound found in naturally available fruits, such as grapes, is utilized in this research for that. In addition, electrochemotherapy (ECT), which involves the application of electrical pulses (EP), was utilized to enhance the uptake of RESV. MDA-MB-231, human TNBC cells were treated with/out RESV, and eight 600-1,000 V/cm, 100 μs pulses at 1 Hz. The cells were characterized by using various assays, including viability assay, and ROS assay. A TNBC cell viability of as low as 20% was obtained at 24 h (it was 13% at 60 h), demonstrating the potential of this novel treatment. ROS production was the highest in the combination of EP at 1,000 V/cm along with RESV at 100 μmol/L. Results indicate that RESV has the potential as an anti-TNBC agent and that EP + RESV can significantly enhance the cell death to reduce MDA-MB-231 cell viability by increasing ROS production and triggering apoptosis.

Injectable Polypeptide Hydrogel Depots Containing Dual Immune Checkpoint Inhibitors and Doxorubicin for Improved Tumor Immunotherapy and Post-Surgical Tumor Treatment

In this work, we developed a strategy for local chemo-immunotherapy through simultaneous incorporation of dual immune checkpoint blockade (ICB) antibodies, anti-cytotoxic T-lymphocyte-associated protein 4 (aCTLA-4) and anti-programmed cell death protein 1 (aPD-1), and a chemotherapy drug, doxorubicin (Dox), into a thermo-gelling polypeptide hydrogel. The hydrogel encapsulating Dox or IgG model antibody showed sustained release profiles for more than 12 days in vitro, and the drug release and hydrogel degradation were accelerated in the presence of enzymes. In comparison to free drug solutions or hydrogels containing Dox or antibodies only, the Dox/aCTLA-4/aPD-1 co-loaded hydrogel achieved improved tumor suppression efficiency, strengthened antitumor immune response, and prolonged animal survival time after peritumoral injection into mice bearing B16F10 melanoma. Additionally, after injection of Dox/aCTLA-4/aPD-1 co-loaded hydrogel into the surgical site following tumor resection, a significantly enhanced inhibition on tumor reoccurrence was demonstrated. Thus, the polypeptide hydrogel-based chemo-immunotherapy strategy has potential in anti-tumor therapy and the prevention of tumor reoccurrence.

Fluoroalkane modified cationic polymers for personalized mRNA cancer vaccines

Messenger RNA (mRNA) vaccines, while demonstrating great successes in the fight against COVID-19, have been extensively studied in other areas such as personalized cancer immunotherapy based on tumor neoantigens. In addition to the design of mRNA sequences and modifications, the delivery carriers are also critical in the development of mRNA vaccines. In this work, we synthesized fluoroalkane-grafted polyethylenimine (F-PEI) for mRNA delivery. Such F-PEI could promote intracellular delivery of mRNA and activate the Toll-like receptor 4 (TLR4)-mediated signaling pathway. The nanovaccine formed by self-assembly of F-PEI and the tumor antigen-encoding mRNA, without additional adjuvants, could induce the maturation of dendritic cells (DCs) and trigger efficient antigen presentation, thereby eliciting anti-tumor immune responses. Using the mRNA encoding the model antigen ovalbumin (mRNAOVA), our F-PEI-based mRNAOVA cancer vaccine could delay the growth of established B16-OVA melanoma. When combined with immune checkpoint blockade therapy, the F-PEI-based MC38 neoantigen mRNA cancer vaccine was able to suppress established MC38 colon cancer and prevent tumor reoccurrence. Our work presents a new tool for mRNA delivery, promising not only for personalized cancer vaccines but also for other mRNA-based immunotherapies.

Multi-Target Potential of Berberine as an Antineoplastic and Antimetastatic Agent: A Special Focus on Lung Cancer Treatment.

Despite therapeutic advancements, lung cancer remains the principal cause of cancer mortality in a global scenario. The increased incidence of tumor reoccurrence and progression and the highly metastatic nature of lung cancer are of great concern and hence require the investigation of novel therapies and/or medications. Naturally occurring compounds from plants serve as important resources for novel drugs for cancer therapy. Amongst these phytochemicals, Berberine, an alkaloid, has been extensively explored as a potential natural anticancer therapeutic agent. Several studies have shown the effectiveness of Berberine in inhibiting cancer growth and progression mediated via several different mechanisms, which include cell cycle arrest, inducing cell death by apoptosis and autophagy, inhibiting cell proliferation and invasion, as well as regulating the expression of microRNA, telomerase activity, and the tumor microenvironment, which usually varies for different cancer types. In this review, we aim to provide a better understanding of molecular insights of Berberine and its various derivative-induced antiproliferative and antimetastatic effects against lung cancer. In conclusion, the Berberine imparts its anticancer efficacy against lung cancers via modulation of several signaling pathways involved in cancer cell viability and proliferation, as well as migration, invasion, and metastasis.

Abstract 2197: Targeted cancer therapy induces APOBEC fueling the evolution of drug resistance

Abstract Introduction: Increasing our understanding of drivers of mutagenesis in lung cancer is critical in our efforts to prevent tumor reoccurrence and resistance. Results: Using the multi-region TRACERx lung cancer study, we uncovered that APOBEC3B is significantly upregulated when compared with other APOBEC family members in EGFR driven lung cancer and identified subclonal enrichment of APOBEC mutational signatures. To model APOBEC mutagenesis in lung cancer, several novel EGFR mutant mouse models containing a human APOBEC3B transgene were generated. Using these models, it was uncovered that APOBEC3B expression is detrimental at tumor initiation when expressed continuously in a p53 wildtype background. This detrimental effect is likely due to elevated chromosomal instability, which was observed to increase significantly with APOBEC3B expression in an EGFR mutant TP53 deficient mouse model. Induction of subclonal expression of APOBEC3B in an EGFR mutant mouse model with tyrosine kinase inhibitor (TKI) therapy resulted in a significant increase in resistant tumor development. Significant downregulation of the base excision repair gene uracil-DNA glycosylase (UNG) was also observed in APOBEC3B expressing mice, which paralleled findings in patient tumors and cell lines treated with TKI therapy. Finally, a mouse mutational signature was identified in APOBEC3B expressing cell lines, reinforcing the idea that APOBEC driven mutagenesis contributes to TKI resistance. Conclusion: This study demonstrates a unique principle by which targeted therapy induces changes within tumors ideal for APOBEC driven tumor evolution, fueling therapy resistance. Citation Format: Manasi Mayekar, Deborah Caswell, Natalie Vokes, Emily K. Law, Wei Wu, William Hill, Eva Gronroos, Andrew Rowan, Maise Al Bakir, Clare Weeden, Caroline E. McCoach, Collin M. Blakely, Nuri Alpay Temiz, Ai Nagano, Daniel L. Kerr, Julia K. Rotow, Oriol Pich, Franziska Haderk, Michelle Dietzen, Carlos Martinez Ruiz, Bruna Almeida, Lauren Cech, Beatrice Gini, Joanna Przewrocka, Chris Moore, Miguel Murillo, Bjorn Bakker, Brandon Rule, Cameron Durfee, Shigeki Nanj, Lisa Tan, Lindsay K. Larson, Prokopios P. Argyris, William L. Brown, Johnny Yu, Carlos Gomez, Philippe Gui, Rachel I. Vogel, Elizabeth A. Yu, Nicholas J. Thomas, Subramanian Venkatesan, Sebastijan Hobor, Su Kit Chew, Nicholas McGranahan, Nnennaya Kanu, Eliezer M. Van Allen, Julian Downward, Reuben S. Harris, Trever Bivona, Charles Swanton. Targeted cancer therapy induces APOBEC fueling the evolution of drug resistance [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 2197.

Enhanced Induction of MDA-MB-231 Cell Death using the Combination of Galloflavin and Electroporation

Triple Negative Breast Cancer (TNBC) is difficult to treat since it lacks the three most commonly targeted hormone receptors. Patients with TNBC are treated with platinum core chemotherapeutics, such as Cisplatin. However, despite the anticancer effects of Cisplatin, TNBC attenuates its effect and develops a resistance eventually, which results in tumor reoccurrence. Hence, there is a critical demand for effective alternative and natural ways to treat TNBC. Towards this, inhibiting TNBC cell proliferation by blocking the key glycolytic enzyme Lactase Dehydrogenase B (LDHB) is one viable option studied in this research. Galloflavin (GF), a potent LDHB inhibitor synthesized from gallic acid, is utilized in this research. In addition, Electrochemotherapy (ECT), which involves the application of electrical pulses (EP), was utilized to enhance GF uptake. MDA-MB-231, human TNBC cells were used for this, with/out Galloflavin, and eight pulses of 600V/cm, 800V/cm, 1000V/cm, and 1200V/cm, at 100μs and 1Hz. The cells were characterized using various assays, including viability, colony-forming, and reactive oxygen species (ROS). Results indicate a TNBC cell viability of as low as 22%, demonstrating the potential of this novel treatment.

Cancer cells use self-inflicted DNA breaks to evade growth limits imposed by genotoxic stress.

Genotoxic therapy such as radiation serves as a frontline cancer treatment, yet acquired resistance that leads to tumor reoccurrence is frequent. We found that cancer cells maintain viability during irradiation by reversibly increasing genome-wide DNA breaks, thereby limiting premature mitotic progression. We identify caspase-activated DNase (CAD) as the nuclease inflicting these de novo DNA lesions at defined loci, which are in proximity to chromatin-modifying CCCTC-binding factor (CTCF) sites. CAD nuclease activity is governed through phosphorylation by DNA damage response kinases, independent of caspase activity. In turn, loss of CAD activity impairs cell fate decisions, rendering cancer cells vulnerable to radiation-induced DNA double-strand breaks. Our observations highlight a cancer-selective survival adaptation, whereby tumor cells deploy regulated DNA breaks to delimit the detrimental effects of therapy-evoked DNA damage.

Prediction time of breast cancer tumor recurrence using Machine Learning

An in-depth study using the database from GLOBOCAN, CDC, and WHO health repository highlights the lethality of breast cancer, taking thousands of lives each year. However, a timely prediction of cancer can help patients to consult the doctor on time. In the past, various studies have successfully predicted the nature of the tumor to be benign or malignant and if the breast cancer tumor will reoccur or not but, no time-based models have been studied. With the help of Machine Learning, this study shows various prediction models that can be used to predict tumor reoccurrence time as accurately as 1 year. Among the 198 patients analyzed, 40% of the total patients were predicted to have breast cancer tumors reoccurring within 1st year of the diagnosis. The proposed machine learning techniques use various classification models such as Spectral clustering, DBSCAN, and k-means along with prediction models like Support Vector Machines (SVM), Decision trees, and Random Forest. The results demonstrate the ability of the model to predict the time taken by the tumor to reoccur or the time taken by the patient for full recovery with the best accuracy of 78.7% using SVM. This population-based study performed on multivariate real attributed characteristics data can therefore provide the patients a reasonable estimate about their recovery time or the time before which they should consult the doctor.

Abstract P148: Glycogen phosphorylase and synthase inhibitors: Novel therapeutic approaches in anaplastic thyroid cancer

Abstract Thyroid cancer (TC) is the most common endocrine cancer. Effective treatment options for papillary (PTC) and follicular (FTC) thyroid cancers afford positive patient prognoses. However, there are no effective, long-lasting treatments for anaplastic thyroid cancer (ATC), which has a median survival of five to six months. While the receptor tyrosine kinase inhibitor sorafenib can extend ATC patient survival to eleven months, tumor reoccurrence and drug resistance often develop. Therefore, there is a need for more effective targeted therapies for ATC. While the cell signaling landscape is well described in ATC, little is known about tumorigenic adaptations in ATC metabolism. Tumors exhibit an increased consumption of glucose compared to normal tissues to fuel tumor progression. Some cancers meet this high glucose requirement by storing and breaking down glycogen. While glycogen has been detected in bovine and canine thyroids, no report thus far has investigated glycogen in normal human thyroids or thyroid cancer. Therefore, our objective was to determine if normal thyroid and TC cells metabolize glycogen and to evaluate pharmacological inhibition of glycogen metabolism in ATC cells. We show for the first time that normal thyroid, PTC, FTC, and ATC cells express glycogen synthase and glycogen phosphorylase brain and liver (PYGB, PYGL) isoforms. We confirmed these observations in patient samples of normal thyroid and TC tissues via immunofluorescence. We revealed that the TC samples expressed high levels of PYGB compared to normal thyroid tissue. Electron microscopy revealed that normal thyroid cells organized glycogen in discrete glycosomes, while ATC cells exhibited smaller, dispersed glycogen packets. Importantly, we demonstrated that the glycogen synthase inhibitor guaiacol depleted glycogen content and reduced ATC cell viability. Conversely, the glycogen phosphorylase inhibitor CP-91,149 (CP) increased glycogen levels and induced apoptosis. Importantly, CP also reduced the number of stem cells in the ATC cell population. We further showed that CP synergized with sorafenib to more effectively inhibit ATC proliferation. CP enhanced glycolysis but inhibited oxidative phosphorylation as revealed using Seahorse. We confirmed an increase in glucose transporter expression using RT-qPCR and glucose import following CP treatment. This possibly represents a futile response to PYGB inhibition. We reasoned that glycogen was preferentially metabolized in ATC to fuel the pentose phosphate pathway to protect against reactive oxygen species (ROS). Indeed, we detected significantly higher levels of ROS in ATC cells treated with CP. We demonstrated that thyroid cells are able to metabolize glycogen and identified a potential biomarker for thyroid cancer (PYGB), which was targeted with CP-91,149. Our work establishes glycogen metabolism as a novel metabolic process in thyroid cells that is associated with TC dedifferentiation and provides insight to the effectiveness of inhibiting glycogen metabolism as a novel therapeutic strategy in ATC. Citation Format: Cole Davidson, Jennifer Tomczak, Eyal Amiel, Frances Carr. Glycogen phosphorylase and synthase inhibitors: Novel therapeutic approaches in anaplastic thyroid cancer [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2021 Oct 7-10. Philadelphia (PA): AACR; Mol Cancer Ther 2021;20(12 Suppl):Abstract nr P148.