Cancers Of Different Origin Research Articles

Autoantibodies against Endophilin A2 as a novel biomarker are beneficial to early diagnosis of breast cancer

BackgroundDue to the lack of early symptoms, breast cancer is frequently overlooked, leading to distant metastases and multi-organ lesions that directly threaten patients’ lives. We have identified a novel tumor marker, antibodies to endophilin A2 (EA2), to improve early diagnosis of breast cancer. MethodsAntibody levels of EA2 were analyzed in sera of patients with cancers of different origins and stages by indirect enzyme-linked immunosorbent assay (ELISA). Diagnostic accuracy and reference range were determined by the area under the receiver operating curve and distribution curve. The levels of EA2 antigen in sera were determined by sandwich ELISA. ResultsThe levels of antibodies against EA2 were higher in sera of patients with breast cancer (P < 0.0001), liver cancer (P = 0.0005), gastric cancer (P = 0.0026), and colon cancer (P = 0.0349) than those in healthy controls, but not in patients with rectal cancer (P = 0.1151), leukemia (P = 0.7508), or lung cancer (P = 0.2247). The highest diagnostic value was for breast cancer, particularly in early cases (AUC = 0.8014) and those with distant metastases (AUC = 0.7885). The titers of EA2 antibodies in sera were correlated with levels of EA2 antigen in breast cancer patients. ConclusionAntibodies to EA2 are novel blood biomarkers for early diagnosis of breast cancer that warrants further study in larger-scale cohort studies.

Abstract 4344: Comprehensive analysis of LINE-1 transposable elements in colorectal cancer

Abstract Background: Colorectal cancer (CRC) is the third most frequent cancer worldwide, and approximately a third of patients die from the disease. There is therefore an urgent need to better understand CRC biology. A particular feature in (colorectal) cancer is the activation of LINE-1 (L1) retrotransposons: DNA fragments which propagate to other places in the genome through an RNA intermediate. Per genome, about 100-150 genomic L1 copies are still retrotransposition-competent, but repressed in most somatic tissues. Their role in tumor development is currently unknown. Recently, the PCAWG consortium characterized the landscape of somatic L1 retrotranspositions in a series of primary cancers of different origin, and identified 124 recurrently active L1 source regions. However, only a limited number of these concerned CRC. Aim: This study aims to perform a comprehensive analysis of L1 activity in a large cohort of metastatic colorectal cancer. Methods: To this end, we retrieved data from the Hartwig Medical Foundation, comprising deep (106x) whole genome sequencing (WGS) data from metastatic CRC (n=745), to compare to breast (n=888) and lung cancer samples (n=640). We determined L1 activity as the number of somatic L1 insertions reported by the HMF DNA analysis pipeline and used the activity of each of the 124 L1 sources as previously reported by the PCAWG consortium. Results: 99% of mCRC samples (n=741) displayed at least 1 somatic L1 retrotransposition, with at least 10 retrotranspositions in 89% of samples. L1 retrotransposition is more prevalent in mCRC than in metastatic lung and breast cancer, in which only 40% and 20% had at least 10 retrotranspositions per sample, respectively. Each cancer type showed a unique profile of active L1 sources. We did not observe a clear preference of L1 insertions for a single genomic region. However, in CRC, the gene most frequently affected in an exon was APC (n=13), an important tumor-suppressor gene. An analysis of somatic SNVs and SVs confirmed an association of mutations in some known L1 regulators such as TP53 with increased L1 activity, whereas mutations in others showed no change in the number of somatic retrotranspositions. Conclusions: We conclude that somatic L1 retrotranspositions are highly prevalent in metastatic colorectal cancer. Presence of L1 insertions in APC suggests retrotranspositions start very early in CRC development and prompts further investigation into earlier CRC stages. Citation Format: Renske de Wit, Soufyan Lakbir, Caterina Buranelli, Gerrit A. Meijer, Sanne Abeln, Remond J. Fijneman. Comprehensive analysis of LINE-1 transposable elements in colorectal cancer [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 4344.

A practical prognostic peripheral blood-based risk model for the evaluation of the likelihood of a response and survival of metastatic cancer patients treated with immune checkpoint inhibitors

BackgroundLess than half of unselected metastatic cancer patients benefit from the immune checkpoint inhibitor (ICI) therapy. Systemic cancer-related inflammation may influence the efficacy of ICIs and thus, systemic inflammatory markers could have prognostic and/or predictive potential in ICI therapy. Here, we aimed to identify a combination of inflammation-related laboratory parameters to establish a practical prognostic risk model for the pretreatment evaluation of a response and survival of ICI-treated patients with different types of metastatic cancers.MethodsThe study-cohort consisted of a real-world patient population receiving ICIs for metastatic cancers of different origins (n = 158). Laboratory parameters determined before the initiation of the ICI treatment were retrospectively collected. Six inflammation-related parameters i.e., elevated values of neutrophils, platelets, C-reactive protein (CRP), erythrocyte sedimentation rate (ESR) and lactate dehydrogenase (LDH), and the presence of anemia, were each scored with one point, giving 0–6 risk points for each patient. The patients with information of all these six parameters (n = 109) were then stratified into low-risk (0–3 points) and high-risk (4–6 points) groups. The overall response rate (ORR), overall survival (OS), and progression-free survival (PFS) according to the risk scores were determined.ResultsThe risk model was strongly associated with the outcome of the patients. The ORR to ICI treatment in the high-risk group was 30.3% in comparison to 53.9% in the low-risk group (p = 0.023). The medians for OS were 10.0 months and 27.3 months, respectively (p < 0.001), and the corresponding medians for PFS were 3.9 months and 6.3 months (p = 0.002). The risk group remained as a significant prognostic factor for both OS (HR 3.04, 95% CI 1.64–5.64, p < 0.001) and PFS (HR 1.79, 95% CI 1.04–3.06, p = 0.035) in the Cox multivariate analyses.ConclusionsWe propose a readily feasible, practical risk model consisted of six inflammation-related laboratory parameters as a tool for outcome prediction in metastatic cancer patients treated with ICIs. The risk model was strongly associated with the outcome of the patients in terms of all the evaluated indicators i.e., ORR, OS and PFS. Yet, further studies are needed to validate the risk model.

DDX5 (p68) orchestrates β-catenin, RelA and SP1 mediated MGMT gene expression in human colon cancer cells: Implication in TMZ chemoresistance

DDX5 (p68) upregulation has been linked with various cancers of different origins, especially Colon Adenocarcinomas. Similarly, across cancers, MGMT has been identified as the major contributor of chemoresistance against DNA alkylating agents like Temozolomide (TMZ). TMZ is an emerging potent chemotherapeutic agent across cancers under the arena of drug repurposing. Recent studies have established that patients with open MGMT promoters are prone to be innately resistant or acquire resistance against TMZ compared to its closed conformation. However, not much is known about the transcriptional regulation of MGMT gene in the context of colon cancer. This necessitates studying MGMT gene regulation which directly impacts the cellular potential to develop chemoresistance against alkylating agents. Our study aims to uncover an unidentified mechanism of DDX5-mediated MGMT gene regulation. Experimentally, we found that both mRNA and protein expression levels of MGMT were elevated in response to p68 overexpression in multiple human colon cancer cell lines and vice-versa. Since p68 cannot directly interact with the MGMT promoter, transcription factors viz., β-catenin, RelA (p65) and SP1 were also studied as reported contributors. Through co-immunoprecipitation and GST-pull-down studies, p68 was established as an interacting partner of SP1 in addition to β-catenin and NF-κB (p50-p65). Mechanistically, luciferase reporter and chromatin-immunoprecipitation assays demonstrated that p68 interacts with the MGMT promoter via TCF4-LEF, RelA and SP1 sites to enhance its transcription. To the best of our knowledge, this is the first report of p68 as a transcriptional co-activator of MGMT promoter and our study identifies p68 as a novel and master regulator of MGMT gene expression.

Regulation of cGAS-STING signalling in cancer: Approach for combination therapy.

Innate immunity plays an important role not only during infection but also homeostatic role during stress conditions. Activation of the immune system including innate immune response plays a critical role in the initiation and progression of tumorigenesis. The innate immune sensor recognizes pathogen-associated molecular patterns (PAMPs) and activates cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) (cGAS-STING) and induces type-1 immune response during viral and bacterial infection. cGAS-STING is regulated differently in conditions like cellular senescence and DNA damage in normal and tumor cells and is implicated in the progression of tumors from different origins. cGAS binds to cytoplasmic dsDNA and synthesize cyclic GMP-AMP (2'3'-cGAMP), which selectively activates STING and downstream IFN and NF-κB activation. We here reviewed the cGAS-STING signalling pathway and its cross-talk with other pathways to modulate tumorigenesis. Further, the review also focused on emerging studies that targeted the cGAS-STING pathway for developing targeted therapeutics and combinatorial regimens for cancer of different origins.

Abstract A09: Targeting of FOXM1 recapitulates NPM1 mutations in chemo-sensitization of AML

Abstract NPM1 mutations are among the most common mutations in CN-AML (Cytogenetically Normal-AML) and are known to enhance chemosensitivity in AML patients. Across multiple co-operative group studies, in the absence of deleterious mutations, patients with NPM1 mutations show superior overall and relapse-free survival. The FOXM1 regulatory network is a major predictor of poor prognosis in human cancers of different origin, including AML. Early AML cell line and patient sample data from our lab demonstrated that nuclear NPM colocalizes with nuclear FOXM1 while mutant NPM sequesters FOXM1 in the cytoplasm. Applying RNAseq differential expression results from published FOXM1 knockout experiments on KG-1 cells and MLL-AF9-transformed mice to Beat AML RNAseq data, we developed a ~200-gene FOXM1 signature that was significantly associated with inferior CR/CRi rate (OR=0.44 [95% CI: 0.21–0.95], p=0.037) in wild type NPM1, wild type FLT3 de novo AML patients. Notably, this FOXM1 signature was not significantly associated with CR/CRi in mutated NPM1, wild type FLT3 patients (OR=1.78 [95% CI: 0.15–21.51], p=0.651). These data suggest that inactivation of FOXM1 may underlie the chemosensitivity conferred by the highly prevalent NPM1 mutation in favorable risk AML. Using our novel network-centric approach, we found a first-in-class small molecule (STL427944) that affects a pathway that limits FOXM1 expression and significantly disrupts the associated regulatory network. To directly address the role of FOXM1 in chemosensitivity of AML cells, we tested two FOXM1-specific inhibitory compounds: STL427944 and its derivative, STL001 (their structures will be disclosed). From a medicinal chemistry standpoint, STL427944 has two main metabolic liabilities, a hydrolytically labile furane-carboxylic acid phenolic ester and a hydrazone. We applied several paths of structural activity relationship (SAR) optimization to overcome these issues from removal of liabilities to bio-isosteric replacement to cyclizations. The ring replacement is likely to have significantly improved the overall stability observed in STL001, resulting in at least !0-fold more active compound with better ‘drug-like’ properties and thus enhanced potency. We showed that 500nM of STL001 partially suppressed expression of FOXM1 protein in AML, while 5mM of STL001 (versus 50mM of STL427944) fully suppressed FOXM1 and sensitized AML cells to venetoclax and cytarabine treatment. Ex vivo treatment of AML patient samples with STL427944 and STL001 resulted in inhibition of nuclear FOXM1 expression according to IHC and downregulation of canonical FOXM1 transcriptional targets as indicated by real-time PCR. This treatment potentiated the efficacy of venetoclax in inhibiting colony forming activity in AML patient samples. Our data suggest that targeting FOXM1 in AML patients with wild type NPM1 may recapitulate NPM1 mutations and will have a robust therapeutic effect leading to more favorable outcome for AML patients. Citation Format: Irum Khan, Sandjeev Raghuwanshi, Andy Kaempf, Jeff Tyner, Alex Domling, Carlos Camacho, Andrei Gartel. Targeting of FOXM1 recapitulates NPM1 mutations in chemo-sensitization of AML [abstract]. In: Proceedings of the AACR Special Conference: Acute Myeloid Leukemia and Myelodysplastic Syndrome; 2023 Jan 23-25; Austin, TX. Philadelphia (PA): AACR; Blood Cancer Discov 2023;4(3_Suppl):Abstract nr A09.

Targeting the IL1β Pathway for Cancer Immunotherapy Remodels the Tumor Microenvironment and Enhances Antitumor Immune Responses.

High levels of IL1β can result in chronic inflammation, which in turn can promote tumor growth and metastasis. Inhibition of IL1β could therefore be a promising therapeutic option in the treatment of cancer. Here, the effects of IL1β blockade induced by the mAbs canakinumab and gevokizumab were evaluated alone or in combination with docetaxel, anti-programmed cell death protein 1 (anti-PD-1), anti-VEGFα, and anti-TGFβ treatment in syngeneic and humanized mouse models of cancers of different origin. Canakinumab and gevokizumab did not show notable efficacy as single-agent therapies; however, IL1β blockade enhanced the effectiveness of docetaxel and anti-PD-1. Accompanying these effects, blockade of IL1β alone or in combination induced significant remodeling of the tumor microenvironment (TME), with decreased numbers of immune suppressive cells and increased tumor infiltration by dendritic cells (DC) and effector T cells. Further investigation revealed that cancer-associated fibroblasts (CAF) were the cell type most affected by treatment with canakinumab or gevokizumab in terms of change in gene expression. IL1β inhibition drove phenotypic changes in CAF populations, particularly those with the ability to influence immune cell recruitment. These results suggest that the observed remodeling of the TME following IL1β blockade may stem from changes in CAF populations. Overall, the results presented here support the potential use of IL1β inhibition in cancer treatment. Further exploration in ongoing clinical studies will help identify the best combination partners for different cancer types, cancer stages, and lines of treatment.

Deep Learning With an Attention Mechanism for Differentiating the Origin of Brain Metastasis Using MR images.

Brain metastasis (BM) is a serious neurological complication of cancer of different origins. The value of deep learning (DL) to identify multiple types of primary origins remains unclear. To distinguish primary site of BM and identify the best DL models. Retrospective. A total of 449 BM derived from 214 patients (49.5% for female, mean age 58 years) (100 from small cell lung cancer [SCLC], 125 from non-small cell lung cancer [NSCLC], 116 from breast cancer [BC], and 108 from gastrointestinal cancer [GIC]) were included. A 3-T, T1 turbo spin echo (T1-TSE), T2-TSE, T2FLAIR-TSE, DWI echo-planar imaging (DWI-EPI) and contrast-enhanced T1-TSE (CE T1-TSE). Lesions were divided into training (n=285, 153 patients), testing (n=122, 93 patients), and independent testing cohorts (n=42, 34 patients). Three-dimensional residual network (3D-ResNet), named 3D ResNet6 and 3D ResNet 18, was proposed for identifying the four origins based on single MRI and combined MRI (T1WI + T2-FLAIR + DWI, CE-T1WI + DWI, CE-T1WI + T2WI + DWI). DL model was used to distinguish lung cancer from non-lung cancer; then SCLC vs. NSCLC for lung cancer classification and BC vs. GIC for non-lung cancer classification was performed. A subjective visual analysis was implemented and compared with DL models. Gradient-weighted class activation mapping (Grad-CAM) was used to visualize the model by heatmaps. The area under the receiver operating characteristics curve (AUC) assess each classification performance. 3D ResNet18 with Grad-CAM and AIC showed better performance than 3DResNet6, 3DResNet18 and the radiologist for distinguishing lung cancer from non-lung cancer, SCLC from NSCLC, and BC from GIC. For single MRI sequence, T1WI, DWI, and CE-T1WI performed best for lung cancer vs. non-lung cancer, SCLC vs. NSCLC, and BC vs. GIC classifications. The AUC ranged from 0.675 to 0.876 and from 0.684 to 0.800 regarding the testing and independent testing datasets, respectively. For combined MRI sequences, the combination of CE-T1WI + T2WI + DWI performed better for BC vs. GIC (AUCs of 0.788 and 0.848 on testing and independent testing datasets, respectively), while the combined MRI approach (T1WI + T2-FLAIR + DWI, CE-T1WI + DWI) could not achieve higher AUCs for lung cancer vs. non-lung cancer, SCLC vs. NSCLC. Grad-CAM helped for model visualization by heatmaps that focused on tumor regions. DL models may help to distinguish the origins of BM based on MRI data. 3 TECHNICAL EFFICACY: Stage 2.

Molecular Mechanisms of Action of Eugenol in Cancer: Recent Trends and Advancement.

Cancer is, at present, among the leading causes of morbidity globally. Despite advances in treatment regimens for cancer, patients suffer from poor prognoses. In this context, the availability of vast natural resources seems to alleviate the shortcomings of cancer chemotherapy. The last decade has seen a breakthrough in the investigations related to the anticancer potential of dietary phytoconstituents. Interestingly, a handsome number of bioactive principles, ranging from phenolic acids, phenylpropanoids, flavonoids, stilbenes, and terpenoids to organosulphur compounds have been screened for their anticancer properties. Among the phenylpropanoids currently under clinical studies for anticancer activity, eugenol is a promising candidate. Eugenol is effective against cancers like breast, cervical, lung, prostate, melanomas, leukemias, osteosarcomas, gliomas, etc., as evident from preclinical investigations. The review aims to focus on cellular and molecular mechanisms of eugenol for cancer prevention and therapy. Based on predetermined criteria, various scholarly repositories, including PubMed, Scopus, and Science Direct were analyzed for anticancer activities of eugenol. Different biochemical investigations reveal eugenol inducing cytotoxicity, inhibiting phases of the cell cycles, programmed cell death, and auto-phagocytosis in studied cancer lines; thus, portraying eugenol as a promising anticancer molecule. A survey of current literature has unveiled the molecular mechanisms intervened by eugenol in exercising its anticancer role. Based on the critical analysis of the literature, eugenol exhibits vivid signaling pathways to combat cancers of different origins. The reports also depict the advancement of novel nano-drug delivery approaches upgrading the therapeutic profile of eugenol. Therefore, eugenol nanoformulations may have enormous potential for both the treatment and prevention of cancer.

Diagnostic Value of 18 F-FACBC PET/MRI in Brain Metastases.

The study aims to evaluate whether combined 18 F-FACBC PET/MRI could provide additional diagnostic information compared with MRI alone in brain metastases. Eighteen patients with newly diagnosed or suspected recurrence of brain metastases received dynamic 18 F-FACBC PET/MRI. Lesion detection was evaluated on PET and MRI scans in 2 groups depending on prior stereotactic radiosurgery (SRS group) or not (no-SRS group). SUVs, time-activity curves, and volumetric analyses of the lesions were performed. In the no-SRS group, 29/29 brain lesions were defined as "MRI positive." With PET, 19/29 lesions were detected and had high tumor-to-background ratios (TBRs) (D max MR , ≥7 mm; SUV max , 1.2-8.4; TBR, 3.9-25.9), whereas 10/29 lesions were undetected (D max MR , ≤8 mm; SUV max , 0.3-1.2; TBR, 1.0-2.7). In the SRS group, 4/6 lesions were defined as "MRI positive," whereas 2/6 lesions were defined as "MRI negative" indicative of radiation necrosis. All 6 lesions were detected with PET (D max MR , ≥15 mm; SUV max , 1.4-4.2; TBR, 3.6-12.6). PET volumes correlated and were comparable in size with contrast-enhanced MRI volumes but were only partially congruent (mean DSC, 0.66). All time-activity curves had an early peak, followed by a plateau or a decreasing slope. 18 F-FACBC PET demonstrated uptake in brain metastases from cancer of different origins (lung, gastrointestinal tract, breast, thyroid, and malignant melanoma). However, 18 F-FACBC PET/MRI did not improve detection of brain metastases compared with MRI but might detect tumor tissue beyond contrast enhancement on MRI. 18 F-FACBC PET should be further evaluated in recurrent brain metastases.

Landscapes of synchronous multiple primary cancers detected by next-generation sequencing.

An increase in the detection rate of multiple primary cancers has been accompanied with declining cancer death rates over the past few decades. However, synchronous multiple primary tumors have gradually increased, and the molecular mechanisms involved in the synchronous occurrence of multiple primary cancers of different origins are unclear. To investigate these mechanisms, we sequenced cancer tissues by FoundationOne CDx. Data were annotated with annovar, and we then performed pathway enrichment analysis. A total of 109 genes that were mutated in all samples were clustered into different diseases, biological processes, and molecular functions. GO and KEGG analyses indicated that the P53 and PKB signaling pathways may be relevant to the occurrence of synchronous multiple primary cancers. In summary, patients with a concordance of mutations in pathogenetic genes may have a higher risk of developing a second cancer. Our research may provide a basis for the development of individualized treatments for synchronous multiple primary cancers.

Prognostic role of hERG1 Potassium Channels in Neuroendocrine Tumours of the Ileum and Pancreas.

hERG1 potassium channels are widely expressed in human cancers of different origins, where they affect several key aspects of cellular behaviour. The present study was designed to evaluate the expression and clinical relevance of hERG1 protein in cancer tissues from patients suffering from neuroendocrine tumours (NETs) of ileal (iNETs) and pancreatic (pNETs) origin, with available clinicopathological history and follow-up. The study was carried out by immunohistochemistry with an anti-hERG1 monoclonal antibody. In a subset of samples, a different antibody directed against the hERG1/β1 integrin complex was also used. The analysis showed for the first time that hERG1 is expressed in human NETs originating from either the ileum or the pancreas. hERG1 turned out to have a prognostic value in NETs, showing (i) a statistically significant positive impact on OS of patients affected by ileal NETs, regardless the TNM stage; (ii) a statistically significant positive impact on OS of patients affected by aggressive (TNM stage IV) disease, either ileal or pancreatic; (iii) a trend to a negative impact on OS of patients affected by less aggressive (TNM stage I-III) disease, either ileal or pancreatic. Moreover, in order to evaluate whether ERG1 was functionally expressed in a cellular model of pNET, the INS1E rat insulinoma cell line was used, and it emerged that blocking ERG1 with a specific inhibitor of the channel (E4031) turned out in a significant reduction in cell proliferation.

Abstract 5480: Aristolochic acid as a scaffold for antitumor drug development

Abstract We have synthesized an analog of aristolochic acid (AA) with potent growth inhibitory activity in various human cancer cell lines and report here on mechanistic studies of this potential therapeutic. AA is a natural product and the main active principle of Aristolochia plants, a known source of antitumor agents. In 1964 due to nephrotoxicity, drug development efforts with AA were terminated following Phase I clinical trial in patients with terminal cancer of different origin. Structure activity studies of AA species allowed us to select a structural analog of AA (RJ-34) that lacks the determinants responsible for the renal toxicity and carcinogenicity of the parent compound. Building further on our experience with AA molecules, we developed a synthetic approach that affords efficient high-yield synthesis of RJ-34. Its structure and purity has been confirmed by high-performance liquid chromatography, liquid chromatography coupled with two-stage mass spectrometry and high resolution nucleic magnetic resonance. Sulforhodamine B assay revealed that RJ-34 has growth inhibitory activity in A549 and HCT-15 human cancer cell lines comparable to or stronger than that of paclitaxel or topotecan. At five nanomolar, RJ-34 inhibited DNA synthesis and cut the growth of A549 cells by 50%, leading to cell cycle arrest in G1/M and G2/S, with apparent apoptosis at concentrations greater than 200 nanomolar. Notably, protein synthesis in cultured cells, as evaluated by puromycin labelling, remained unaffected. RJ-34 was screened against the NCI-60 cell line panel - encompassing sixty human cancer cell lines from various tissues - providing clues to its mechanisms of action; namely, that RJ-34 acts through inhibition of DNA topoisomerases I and II and/or DNA intercalation. Follow-up studies using purified calf Topo I and human Topo II alpha and various plasmid substrates confirmed the role of RJ-34 as a DNA intercalator and human Topoisomerase II alpha poison. The pattern of activity of RJ-34 in the NCI-60 panel was distinct from that of AA and aristolactam - another related compound - suggesting that RJ-34 acts by mechanisms distinct from AA. In summary, RJ-34— a non-nephrotoxic analog of aristolochic acid— has a potent growth inhibitory activity in various human cancer cell lines with a mechanism of action different from the parent AA. Moving forward, pre-clinical pharmacokinetics, safety and efficacy studies are necessary to establish the potential of RJ-34 for development as an anticancer therapeutic. Citation Format: Keiji Hashimoto, Rajesh Chennamshetti, Radha Bonala, Francis Johnson, Arthur P. Grollman, Viktoriya S. Sidorenko. Aristolochic acid as a scaffold for antitumor drug development [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 5480.

Abstract 2800: Use of an optimized machine learning algorithm to develop DNA methylation markers for detecting colorectal cancer (CRC)

Abstract Introduction: Epigenetic changes including methylation occur early in tumorigenesis and are known to be highly pervasive across a tumor type. The DNA methylation pattern can vary between individuals with or without cancer and also in patients with cancer of different origins. In this study, we investigated the discovery of comprehensive markers and validation of the diagnostic and prognostic potential of colorectal cancer. Methods: Patients with various stage of colorectal cancer were eligible for the current study, mainly stage III. We generated genome-wide methylation data from 379 colorectal cancer (CRC) tissues and 330 available paired adjacent normal mucosa tissues from Korean patients by Illumina EPIC Human Methylation microarray targeting 860,000~ CpG sites. A machine learning algorithm was used to build an optimized prediction model and select the tumor specific markers based on through theses CpG sites. Then, the risk score was devised for prognosis using this marker set. Finally, in order to validate the rule of CpG sites, the genomic location and pathway enrichment analysis was performed by CHROMHMM and Metascape. Results: 379 colorectal cancer tissues and 330 paired adjacent normal mucosal tissues were included for analysis. Clinical stages of the included patients were, III in N (61.2%), II in N (19.5%), and IV in N (11.9%). A total of 305 methylation markers that showed statistically significant differences between normal and cancer tissues were selected. Our model could accurately identify CRC (areas under the curve for the training and validation cohorts: 0.968 and 0.984, respectively). Using our prediction model, the colorectal cancer patients were predicted as colorectal cancer accurately in the methylation data from TCGA (COREAD; colorectal cancer tissue DNA) and GEO dataset (plasma cfDNA from colorectal cancer patients). The risk score comprising the subset of 305 methylation markers was calculated, and poor prognosis was predicted in the high-risk score group (overall survival P &amp;lt;0.1, progression-free survival P &amp;lt; 0.01). Gene ontology (GO) enrichment analysis showed that the 305 CpG sites were enriched in transcription regulatory regions (160/305, 52.5%) and were associated with developmental process and carcinogenesis (GO: 0032502, P &amp;lt;0.001; C4721208, P &amp;lt;0.001). Conclusions: In summary, the performance of our prediction model with these 305 CpG sites was highly accurate for CRC diagnosis, and the optimized risk score could predict the prognosis of Korean CRC patients Citation Format: Jun-Kyu Kang, Su Yeon Kim, Yoojoo Lim, Hwang-Phill Kim, Tae-You Kim. Use of an optimized machine learning algorithm to develop DNA methylation markers for detecting colorectal cancer (CRC) [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 2800.

Cancer Chemoprevention: A Strategic Approach Using Phytochemicals.

Cancer chemoprevention approaches are aimed at preventing, delaying, or suppressing tumor incidence using synthetic or natural bioactive agents. Mechanistically, chemopreventive agents also aid in mitigating cancer development, either by impeding DNA damage or by blocking the division of premalignant cells with DNA damage. Several pre-clinical studies have substantiated the benefits of using various dietary components as chemopreventives in cancer therapy. The incessant rise in the number of cancer cases globally is an issue of major concern. The excessive toxicity and chemoresistance associated with conventional chemotherapies decrease the success rates of the existent chemotherapeutic regimen, which warrants the need for an efficient and safer alternative therapeutic approach. In this scenario, chemopreventive agents have been proven to be successful in protecting the high-risk populations from cancer, which further validates chemoprevention strategy as rational and promising. Clinical studies have shown the effectiveness of this approach in managing cancers of different origins. Phytochemicals, which constitute an appreciable proportion of currently used chemotherapeutic drugs, have been tested for their chemopreventive efficacy. This review primarily aims to highlight the efficacy of phytochemicals, currently being investigated globally as chemopreventives. The clinical relevance of chemoprevention, with special emphasis on the phytochemicals, curcumin, resveratrol, tryptanthrin, kaempferol, gingerol, emodin, quercetin genistein and epigallocatechingallate, which are potential candidates due to their ability to regulate multiple survival pathways without inducing toxicity, forms the crux of this review. The majority of these phytochemicals are polyphenols and flavanoids. We have analyzed how the key molecular targets of these chemopreventives potentially counteract the key drivers of chemoresistance, causing minimum toxicity to the body. An overview of the underlying mechanism of action of these phytochemicals in regulating the key players of cancer progression and tumor suppression is discussed in this review. A summary of the clinical trials on the important phytochemicals that emerge as chemopreventives is also incorporated. We elaborate on the pre-clinical and clinical observations, pharmacokinetics, mechanism of action, and molecular targets of some of these natural products. To summarize, the scope of this review comprises of the current status, limitations, and future directions of cancer chemoprevention, emphasizing the potency of phytochemicals as effective chemopreventives.

High Expression of PPM1D Induces Tumors Phenotypically Similar to TP53 Loss-of-Function Mutations in Mice.

Simple SummaryAberrant expression of the PPM1D gene which encodes a phosphatase called WIP1 is frequently observed in cancers of different origins. WIP1 is a negative regulator of the tumor suppressor p53. Improper inactivation of p53 results in genomic instability and can induce neoplastic transformation. We show that overexpression of PPM1D induces tumors in mice similar to cancers harboring p53 mutations. Our results suggest that PPM1D can act as an oncogenic driver by inducing genomic instability, impaired growth arrest, and apoptotic escape that can result in neoplastic transformation and malignant tumor development. PPM1D is a negative regulator of p53 and genomic aberrations resulting in increased activity of PPM1D have been observed in cancers of different origins, indicating that PPM1D has oncogenic properties. We established a transgenic mouse model overexpressing PPM1D and showed that these mice developed a wide variety of cancers. PPM1D-expressing mice developed tumors phenotypically and genetically similar to tumors in mice with dysfunctional p53. T-cell lymphoblastic lymphoma was the most frequent cancer observed in these mice (55%) followed by adenocarcinomas (24%), leukemia (12%) and other solid tumors including neuroblastoma. Characterization of T-cell lymphomas in mice overexpressing PPM1D demonstrates Pten-deletion and p53-accumulation similar to mice with p53 loss-of-function. Also, Notch1 mutations which are recurrently observed in T-cell acute lymphoblastic lymphoma (T-ALL) were frequently detected in PPM1D-transgenic mice. Hence, PPM1D acts as an oncogenic driver in connection with cellular stress, suggesting that the PPM1D gene status and expression levels should be investigated in TP53 wild-type tumors.

CD44v6 Defines a New Population of Circulating Tumor Cells Not Expressing EpCAM.

Simple SummaryIn the present work, we describe (for the first time) the use of the transmembrane protein, CD44v6, to detect CTCs from blood samples of several patients with colorectal or breast cancer. We used CD44v6 antibodies to demonstrate that live CTCs can be specifically purified from CRC patient blood samples via magnetic bead- or FACS-based isolation techniques. Finally, we demonstrated that CD44v6-positive CTCs rarely expressed EpCam, which is currently the gold standard to enumerate CTCs, suggesting the need to use a combination of markers for a more comprehensive view of CTC heterogeneity.Circulating tumor cells (CTCs) are promising diagnostic and prognostic tools for clinical use. In several cancers, including colorectal and breast, the CTC load has been associated with a therapeutic response as well as progression-free and overall survival. However, counting and isolating CTCs remains sub-optimal because they are currently largely identified by epithelial markers such as EpCAM. New, complementary CTC surface markers are therefore urgently needed. We previously demonstrated that a splice variant of CD44, CD44 variable alternative exon 6 (CD44v6), is highly and specifically expressed by CTC cell lines derived from blood samples in colorectal cancer (CRC) patients. Two different approaches—immune detection coupled with magnetic beads and fluorescence-activated cell sorting—were optimized to purify CTCs from patient blood samples based on high expressions of CD44v6. We revealed the potential of the CD44v6 as a complementary marker to EpCAM to detect and purify CTCs in colorectal cancer blood samples. Furthermore, this marker is not restricted to colorectal cancer since CD44v6 is also expressed on CTCs from breast cancer patients. Overall, these results strongly suggest that CD44v6 could be useful to enumerate and purify CTCs from cancers of different origins, paving the way to more efficacious combined markers that encompass CTC heterogeneity.

Systematic Review and Meta-Analysis of In Vitro Anti-Human Cancer Experiments Investigating the Use of 5-Aminolevulinic Acid (5-ALA) for Photodynamic Therapy.

5-Aminolevulinic acid (5-ALA) is an amino acid derivative and a precursor of protoporphyrin IX (PpIX). The photophysical feature of PpIX is clinically used in photodynamic diagnosis (PDD) and photodynamic therapy (PDT). These clinical applications are potentially based on in vitro cell culture experiments. Thus, conducting a systematic review and meta-analysis of in vitro 5-ALA PDT experiments is meaningful and may provide opportunities to consider future perspectives in this field. We conducted a systematic literature search in PubMed to summarize the in vitro 5-ALA PDT experiments and calculated the effectiveness of 5-ALA PDT for several cancer cell types. In total, 412 articles were identified, and 77 were extracted based on our inclusion criteria. The calculated effectiveness of 5-ALA PDT was statistically analyzed, which revealed a tendency of cancer-classification-dependent sensitivity to 5-ALA PDT, and stomach cancer was significantly more sensitive to 5-ALA PDT compared with cancers of different origins. Based on our analysis, we suggest a standardized in vitro experimental protocol for 5-ALA PDT.

Isoforms of the p53 Family and Gastric Cancer: A Ménage à Trois for an Unfinished Affair.

Simple SummaryThe p53 family is a complex family of transcription factors with different cellular functions that are involved in several physiological processes. A massive amount of data has been accumulated on their critical role in the tumorigenesis and the aggressiveness of cancers of different origins. If common features are observed, there are numerous specificities that may reflect particularities of the tissues from which the cancers originated. In this regard, gastric cancer tumorigenesis is rather remarkable, as it is induced by bacterial and viral infections, various chemical carcinogens, and familial genetic alterations, which provide an example of the variety of molecular mechanisms responsible for cell transformation and how they impact the p53 family. This review summarizes the knowledge gathered from over 40 years of research on the role of the p53 family in gastric cancer, which still displays one of the most elevated mortality rates amongst all types of cancers.Gastric cancer is one of the most aggressive cancers, with a median survival of 12 months. This illustrates its complexity and the lack of therapeutic options, such as personalized therapy, because predictive markers do not exist. Thus, gastric cancer remains mostly treated with cytotoxic chemotherapies. In addition, less than 20% of patients respond to immunotherapy. TP53 mutations are particularly frequent in gastric cancer (±50% and up to 70% in metastatic) and are considered an early event in the tumorigenic process. Alterations in the expression of other members of the p53 family, i.e., p63 and p73, have also been described. In this context, the role of the members of the p53 family and their isoforms have been investigated over the years, resulting in conflicting data. For instance, whether mutations of TP53 or the dysregulation of its homologs may represent biomarkers for aggressivity or response to therapy still remains a matter of debate. This uncertainty illustrates the lack of information on the molecular pathways involving the p53 family in gastric cancer. In this review, we summarize and discuss the most relevant molecular and clinical data on the role of the p53 family in gastric cancer and enumerate potential therapeutic innovative strategies.

Enhanced tumor suppression by conditionally replicating adenovirus in multidrug-resistant human ovarian carcinoma

Background: Breast and ovarian cancers are among the most common and deadly gynecologic malignancies. Today, interest in the non-cytotoxic drug development is at an all-time high, albeit platinum-based combination chemotherapy is still the standard of care for ovarian cancer. However, the treatment of advanced malignancies is restricted due to chemotherapy resistance, which in most cases is acquired. Therefore, identifying novel anti-cancer strategies for gynecological cancers is imperative. We have developed a highly tumor-targeting oncolytic adenovirus by controlling its replication via tumor-specific promotor, survivin. Hitherto, we have tested the anti-tumor potency of this genetically engineered oncolytic virus against breast and lung cancers and found it very toxic and tumor-targeting. In the present study, we continued our investigation of using survivin responsive conditionally replicating adenovirus (CRAd) to chemotherapy-resistant cancers of different origins.