Stages Of Carcinogenesis Research Articles

Novel Non-Cyclooxygenase Inhibitory Derivative of Sulindac Inhibits Breast Cancer Cell Growth In Vitro and Reduces Mammary Tumorigenesis in Rats.

The nonsteroidal anti-inflammatory drug (NSAID) sulindac demonstrates attractive anticancer activity, but the toxicity resulting from cyclooxygenase (COX) inhibition and the suppression of physiologically important prostaglandins precludes its long-term, high dose use in the clinic for cancer prevention or treatment. While inflammation is a known tumorigenic driver, evidence suggests that sulindac's antineoplastic activity is partially or fully independent of its COX inhibitory activity. One COX-independent target proposed for sulindac is cyclic guanosine monophosphate phosphodiesterase (cGMP PDE) isozymes. Sulindac metabolites, i.e., sulfide and sulfone, inhibit cGMP PDE enzymatic activity at concentrations comparable with those associated with cancer cell growth inhibitory activity. Additionally, the cGMP PDE isozymes PDE5 and PDE10 are overexpressed during the early stages of carcinogenesis and appear essential for cancer cell proliferation and survival based on gene silencing experiments. Here, we describe a novel amide derivative of sulindac, sulindac sulfide amide (SSA), which was rationally designed to eliminate COX-inhibitory activity while enhancing cGMP PDE inhibitory activity. SSA was 68-fold and 10-fold less potent than sulindac sulfide (SS) in inhibiting COX-1 and COX-2, respectively, but 10-fold more potent in inhibiting growth and inducing apoptosis in breast cancer cells. The pro-apoptotic activity of SSA was associated with inhibition of cGMP PDE activity, elevation of intracellular cGMP levels, and activation of cGMP-dependent protein kinase (PKG) signaling, as well as the inhibition of β-catenin/Tcf transcriptional activity. SSA displayed promising in vivo anticancer activity, resulting in a 57% reduction in the incidence and a 62% reduction in the multiplicity of tumors in the N-methyl-N-nitrosourea (MNU)-induced model of breast carcinogenesis. These findings provide strong evidence for cGMP/PKG signaling as a target for breast cancer prevention or treatment and the COX-independent anticancer properties of sulindac. Furthermore, this study validates the approach of optimizing off-target effects by reducing the COX-inhibitory activity of sulindac for future targeted drug discovery efforts to enhance both safety and efficacy.

Gastric microbiota in gastric cancer: Different roles of Helicobacter pylori and other microbes.

Gastric cancer (GC) is one of the leading causes of cancer-related deaths worldwide. The gastric microbiota plays a critical role in the development of GC. First, Helicobacter pylori (H. pylori) infection is considered a major risk factor for GC. However, recent studies based on microbiota sequencing technology have found that non-H. pylori microbes also exert effects on gastric carcinogenesis. Following the infection of H. pylori, gastric microbiota dysbiosis could be observed; the stomach is dominated by H. pylori and the abundances of non-H. pylori microbes reduce substantially. Additionally, decreased microbial diversity, alterations in the microbial community structure, negative interactions between H. pylori and other microbes, etc. occur, as well. With the progression of gastric lesions, the number of H. pylori decreases and the number of non-H. pylori microbes increases correspondingly. Notably, H. pylori and non-H. pylori microbes show different roles in different stages of gastric carcinogenesis. In the present mini-review, we provide an overview of the recent findings regarding the role of the gastric microbiota, including the H. pylori and non-H. pylori microbes, in the development of GC.

Utility of COX-2 as Immunohistochemical Prognostic Marker in Relation to Various Histopathological Parameters and TNM Staging in Colorectal Carcinoma

Introduction: The most prevalent neoplasm of the gastrointestinal system is colorectal carcinoma. After lung and breast carcinoma, malignant colorectal cancer appears to be characterised by inflammation. Among the numerous recognised indicators of inflammation, Cyclooxygenase-2 (COX-2) has been identified as playing a key role in the early phases of carcinogenesis. The link between higher expression of COX-2 and the early stages of carcinogenesis and cancer development implies that COX-2 might be a target for precancerous colorectal lesion imaging. Aim: To assess the expression of COX-2 in colorectal carcinoma and the association with various histopathological parameters and Tumour Node Metastasis (TNM) staging. Materials and Methods: The current study is an observational, cross-sectional, retrospective, and prospective study that will take place in the Histopathology and Immunohistochemistry unit of the Department of Pathology, Jawaharlal Nehru Medical College, Sawangi (Meghe), Wardha, Maharashtra, India. Sample collection will be done during the the period of august 2021 to july 2024. The study included approximately 60-65 resected specimens from confirmed and planned Colectomy, Hemicolectomy, and Proctocolectomy specimens received in the Department of General Pathology, JNMC. Observations and results will be collected from the immunohistochemistry study by using COX-2 as a prognostic marker in colorectal carcinoma and correlating it with the TNM staging. Statistical analysis will be made by chi-square test and regression analysis.

Regulation of Gut Microbiota: Is It Hope for Cure of Colorectal Cancer?

The gut microbiota dysbiosis is linked with inflammatory bowel diseases, hypertension, atherosclerosis, hepatitis, neuropsychiatric disorders, diabetes, obesity, asthma, and development of cancer. Despite the substantial developments in oncology, cancer is still not in the category of curative diseases. However, significant steps are being taken in this direction through the identification of factors that play a role in the stages of complex carcinogenesis. Recent data obtained from human gut microbiota has shown that commensal microorganism species living on the epithelial surfaces of the intestines have an active role in this process and are also associated with personal responses to cancer treatment and toxicity. We now know more about the role of Fusobacterium nucleatum, an important member of the gut microbiota complex, as well as other microorganisms in the formation, treatment, diagnosis, and screening of colorectal cancer. In conclusion, the growing knowledge of microbiota, a key factor in colorectal cancer formation and treatment stages, will be able to change the early detection, treatment, and follow-up of these cancers. In this review, the role of gut microbiota in colorectal carcinogenesis and cancer formation mechanisms, significance in treatment and prognosis, and potential use in cancer prevention and screening have evaluated based on the data obtained from recent studies.

Emerging nano-strategies against tumour microenvironment (TME): a review

The non-cancerous cells and substances found in tumours, including the chemicals they create and release, are referred to as the tumour microenvironment. Carcinogenesis relies on the tumour microenvironment because it contains tumour cells that communicate with neighbouring cells via the circulatory and lymphatic systems. During all stages of carcinogenesis, non-malignant cells in the tumour microenvironment promote unchecked cell proliferation. Changes in the genetics and epigenetics of tumour cells and the rearrangement of TME components, which happen when these two things work together, affect the formation and growth of tumours. Tissue-specific exchanges between tumour cells and their surroundings are critical to understanding the underlying mechanism. With the tremendous advancements in nanomedicine, TME modulation has made significant strides lately. Drug distribution using nanotechnology has a number of benefits, including increased circulation time, cargo delivery to the appropriate location, enhanced bioavailability, reduced toxicity, etc. High interstitial pressure and dense stroma prevent the extravasation and uniform distribution of nanocarriers in TME, but leaky vasculature, acidic, and hypoxic circumstances of TME aid in the aggregation of customised nanoparticles. The goal of the review is to look into the idea of the tumour microenvironment by doing a critical analysis of past research. By briefly analysing stromal components, therapeutic opportunities, and limitations provided by TME for nanoparticulate drug delivery, this paper primarily analyses the potential of nanotherapeutics in targeting TME. Additionally, updated details on TME remodelling techniques for better drug delivery and precise targeting of particular stromal components are provided.

Anticancer activity of glycoalkaloids from Solanum plants: A review.

Cancer is still one of the main causes of death worldwide. For this reason, new compounds that have chemotherapeutic potential have been identified. One such group of substances is Solanaceae glycoalkaloids (GAs). They are natural compounds produced by plants widely used in traditional medicine for healing many disorders. Among others, GAs exhibit significant antitumor properties, for example, a strong inhibitory effect on cancer cell growth. This activity can result in the induction of tumor cell apoptosis, which can occur via different molecular pathways. The molecular mechanisms of the action of GAs are the subject of intensive research, as improved understanding could lead to the development of new cancer therapies. The genetic basis for the formation of neoplasms are mutations in protooncogenes, suppressors, and apoptosis-controlling and repair genes; therefore, substances with antineoplastic properties may affect the levels of their expression or the levels of their expression products. Therapeutic compounds can be applied separately or in combination with other drugs to increase the efficiency of cancer therapy; they can act on the cell through various mechanisms at different stages of carcinogenesis, inducing the process of apoptosis, blocking cell proliferation and migration, and inhibiting angiogenesis. This review summarizes the newest studies on the anticancer properties of solanine (SN), chaconine (CH), solasonine (SS), solamargine (SM), tomatine (TT) and their extracts from Solanum plants.

MiR-199a-3p Induces Mesenchymal to Epithelial Transition of Keratinocytes by Targeting RAP2B

Cutaneous squamous cell carcinoma (CSCC) is an epidermal skin cancer that evolves from normal epidermis along several pre-malignant stages. Previously we found specific miRNAs alterations in each step along these stages. miR-199a-3p expression decreases at the transition to later stages. A crucial step for epithelial carcinoma cells to acquire invasive capacity is the disruption of cell-cell contacts and the gain of mesenchymal motile phenotype, a process known as epithelial-to-mesenchymal transition (EMT). This study aims to study the role of decreased expression of miR-199a-3p in keratinocytes' EMT towards carcinogenesis. First, we measured miR-199a-3p in different stages of epidermal carcinogenesis. Then, we applied Photoactivatable Ribonucleoside-Enhanced Crosslinking and Immunoprecipitation (PAR-CLIP) assay to search for possible biochemical targets of miR-199a-3p and verified that Ras-associated protein B2 (RAP2B) is a bona-fide target of miR-199a-3p. Next, we analyzed RAP2B expression, in CSCC biopsies. Last, we evaluated possible mechanisms leading to decreased miR-199a-3p expression. miR-199a-3p induces a mesenchymal to epithelial transition (MET) in CSSC cells. Many of the under-expressed genes in CSCC overexpressing miR-199a-3p, are possible targets of miR-199a-3p and play roles in EMT. RAP2B is a biochemical target of miR-199a-3p. Overexpression of miR-199a-3p in CSCC results in decreased phosphorylated focal adhesion kinase (FAK). In addition, inhibiting FAK phosphorylation inhibits EMT marker genes' expression. In addition, we proved that DNA methylation is part of the mechanism by which miR-199a-3p expression is inhibited. However, it is not by the methylation of miR-199a putative promoter. These findings suggest that miR-199a-3p inhibits the EMT process by targeting RAP2B. Inhibitors of RAP2B or FAK may be effective therapeutic agents for CSCC.

Exploratory Metabolomics Underscores the Folate Enzyme ALDH1L1 as a Regulator of Glycine and Methylation Reactions.

Folate (vitamin B9) is involved in one-carbon transfer reactions and plays a significant role in nucleic acid synthesis and control of cellular proliferation, among other key cellular processes. It is now recognized that the role of folates in different stages of carcinogenesis is complex, and more research is needed to understand how folate reactions become dysregulated in cancers and the metabolic consequences that occur as a result. ALDH1L1 (cytosolic 10-formyltetrahydrofolate dehydrogenase), an enzyme of folate metabolism expressed in many tissues, is ubiquitously downregulated in cancers and is not expressed in cancer cell lines. The RT4 cell line (derived from papillary bladder cancer) which expresses high levels of ALDH1L1 represents an exception, providing an opportunity to explore the metabolic consequences of the loss of this enzyme. We have downregulated this protein in RT4 cells (shRNA driven knockdown or CRISPR driven knockout) and compared metabolomes of ALDH1L1-expressing and -deficient cells to determine if metabolic changes linked to the loss of this enzyme might provide proliferative and/or survival advantages for cancer cells. In this study, cell extracts were analyzed using Ultra High Performance Liquid Chromatography High Resolution Mass Spectrometry (UHPLC-HR-MS). A total of 13,339 signals were identified or annotated using an in-house library and public databases. Supervised and unsupervised multivariate analysis revealed metabolic differences between RT4 cells and ALDH1L1-deficient clones. Glycine (8-fold decrease) and metabolites derived from S-adenosylmethionine utilizing pathways were significantly decreased in the ALDH1L1-deficient clones, compared with RT4 cells. Other changes linked to ALDH1L1 downregulation include decreased levels of amino acids, Krebs cycle intermediates, and ribose-5-phosphate, and increased nicotinic acid. While the ALDH1L1-catalyzed reaction is directly linked to glycine biosynthesis and methyl group flux, its overall effect on cellular metabolism extends beyond immediate metabolic pathways controlled by this enzyme.

Gender Dimorphism in Hepatic Carcinogenesis-Related Gene Expression Associated with Obesity as a Low-Grade Chronic Inflammatory Disease

Non-alcoholic fatty liver disease (NAFLD) and hepatocellular carcinoma (HCC) show clear evidence of sexual dimorphism, with a significantly higher incidence in males. Among the determining factors that could explain this sex-based difference, the specific distribution of fat by sex has been suggested as a primary candidate, since obesity is a relevant risk factor. In this context, obesity, considered a low-grade chronic inflammatory pathology and responsible for the promotion of liver disease, could lead to sexual dimorphism in the expression profile of genes related to tumor development. When we compared the expression levels of genes associated with the early stages of carcinogenesis in the liver between male and female diet-induced obesity (DIO) rats, we observed that the expression pattern was similar in obese male and female animals. Interestingly, the SURVIVIN/BIRC5 oncogene showed a higher expression in male DIO rats than in female DIO and lean rats. This trend related to sexual dimorphism was observed in leukocytes from patients with obesity, although the difference was not statistically significant. In conclusion, this study evidenced a similar pattern in the expression of most carcinogenesis-related genes in the liver, except SUVIVIN/BIRC5, which could be a predictive biomarker of liver carcinogenesis predisposition in male patients with obesity.

Oral Bacteriome and Mycobiome across Stages of Oral Carcinogenesis.

Oral microbial dysbiosis contributes to the development of oral squamous cell carcinoma (OSCC). Numerous studies have focused on variations in the oral bacterial microbiota of patients with OSCC. However, similar studies on fungal microbiota, another integral component of the oral microbiota, are scarce. Moreover, there is an evidence gap regarding the role that microecosystems play in different niches of the oral cavity at different stages of oral carcinogenesis. Here, we catalogued the microbial communities in the human oral cavity by profiling saliva, gingival plaque, and mucosal samples at different stages of oral carcinogenesis. We analyzed the oral bacteriome and mycobiome along the health-premalignancy-carcinoma sequence. Some species, including Prevotella intermedia, Porphyromonas endodontalis, Acremonium exuviarum, and Aspergillus fumigatus, were enriched, whereas others, such as Streptococcus salivarius subsp. salivarius, Scapharca broughtonii, Mortierella echinula, and Morchella septimelata, were depleted in OSCC. These findings suggest that an array of signature species, including bacteria and fungi, are closely associated with oral carcinogenesis. OSCC-associated diversity differences, species distinction, and functional alterations were most remarkable in mucosal samples, not in gingival plaque or saliva samples, suggesting an urgent need to define oral carcinogenesis-associated microbial dysbiosis based on the spatial microbiome. IMPORTANCE Abundant oral microorganisms constitute a complex microecosystem within the oral environment of the host, which plays a critical role in the adjustment of various physiological and pathological states of the oral cavity. In this study, we demonstrated that variations in the "core microbiome" may be used to predict carcinogenesis. In addition, sample data collected from multiple oral sites along the health-premalignancy-carcinoma sequence increase our understanding of the microecosystems of different oral niches and their specific changes during oral carcinogenesis. This work provides insight into the roles of bacteria and fungi in OSCC and may contribute to the development of early diagnostic assays and novel treatments.

Temporal and spatial characteristics of tumor evolution in a mouse model of oral squamous cell carcinoma

ObjectivesWe aimed to elucidate the temporal and spatial characteristics of tumor evolution in an oral squamous cell carcinoma (OSCC) mouse model with higher burden of lymphatic metastasis through high-throughput sequencing.MethodsThe OSCC model was established in 9 mice. DNA was extracted from the tumors of primary tongue lesions and disseminated tumor cells (DTCs) of submandibular gland lymph nodes and bone marrow, and then whole genome sequencing was performed. After bioinformatics analysis, somatic single-nucleotide variants (SSNVs) and copy number variations (CNVs) data were obtained. Based on SSNVs, clonal architecture and ancestor-descendant relationships among tumor cell subclones were elucidated.ResultsA total of 238 tumor-related SSNVs with 120 high-frequency mutated genes were obtained from 36 samples of 9 mice by whole-genome sequencing. The number of unique SSNVs in the primary lesion, submandibular lymph node and bone marrow was greater than the number of shared SSNVs. Furthermore, the primary lesion-originated subclones, which were identified by SSNVs, were also detected in submandibular lymph nodes in the early stage of oral carcinogenesis. Moreover, at different histopathological stages, unique subclones were also identified in DTCs isolated from lymph nodes.ConclusionTumor heterogeneity is significant in primary tumor cells and disseminated tumor cells. OSCC cells probably disseminate to lymph nodes in the early stage of oral carcinogenesis. OSCC is characterized by polyclonal dissemination, and the evolutionary trajectory of DTCs is potentially dominated by the tumor microenvironment.

Oxidative imbalance increases the risk for colonic polyp and colorectal cancer development.

The role of oxidative stress in the pathogenesis of colorectal carcinoma (CRC) has garnered considerable interest recently. Specific oxidative factors have been implicated in the pathogenesis of adenomatous polyps and ultimately adenocarcinoma. To evaluate the effect of oxidative imbalance as quantified by specific serological markers in the development of sporadic colon adenocarcinoma. A total of 170 patients that underwent endoscopy of the lower gastrointestinal tract in a tertiary center within 3 years were included in the study. They were allocated in three groups; those with sporadic colon adenocarcinoma (n = 56, 32.9%), those with colonic polyps (n = 33, 19.4%) and healthy controls (n = 81, 47.7%). All patients were evaluated for oxidant activity and antioxidant capacity with serum measurements of specific markers such as vitamins A, 25(OH) D3, E, C, B12, folic acid, glutathione, selenium (Se), zinc (Zn), free iron (Fe2+), and malondialdehyde and results were compared between groups. Serum levels of vitamins C, E, D, Se, Zn, vitamin B12 and total antioxidant capacity were significantly lower in the combined neoplasia/polyp group than in the control group (P = 0.002, P = 0.009, P < 0.001, P < 0.001, P < 0.001, P = 0.020 and P < 0.001, correspondingly). Increased levels of vitamin E (P = 0.004), vitamin D (P < 0.001), Se (P < 0.001) and Zn (P < 0.001) seem to bestow a protective effect on the development of CRC. For vitamin D (P < 0.001) and Zn (P = 0.036), this effect seems to extend to the development of colon polyps as well. On the other hand, elevated serum levels of malondialdehyde are associated with a higher risk of CRC (OR = 2.09 compared to controls, P = 0.004). Regarding colonic polyp development, increased concentrations of vitamin Α and Fe2+ are associated with a higher risk, whereas lower levels of malondialdehyde with a lower risk. Increased oxidative stress may play an important role in the pathogenesis and progression of CRC. Antioxidants' presence may exert a protective effect in the very early stages of colon carcinogenesis.

Abstract A065: A Western-style mimicking high-fat diet increases early stage pancreatic carcinogenesis in a KC murine model

Abstract Background: Pancreatic cancer is the 3rd leading cause of cancer-related deaths in the USA. Given the limited clinical benefit of current treatments, pancreatic cancer prevention appears as a key approach to lowering the mortality and suffering caused by this disease. A key modifiable risk factor for pancreatic cancer is the diet. Previous studies have indicated that high fat diets, but also high sugar diets, accelerate pancreatic carcinogenesis. Although the link between increased body fatness and pancreatic cancer risk is apparent, the specific role played by the different dietary fats remains unclear. Moreover, the impact of only diets rich in fats with an omega-6 to omega-3 fatty acid (FA) ratio resembling that of a Western-style diet, remains unclear. Objective: To determine the impact of a high fat diet, that mimics the Western-style diet with a ratio of about 10 parts of omega-6 FA to each omega-3 FA, on early stages of pancreatic carcinogenesis in a clinically relevant, genetically engineered LSL- KrasLSL-G12D; Ptf1aCre/+ (KC) model of pancreatic cancer. Methods: Cohorts of male and female KC mice (N= 44; 10-12 males and females per diet group) were weaned at three weeks of age, single housed, and placed on the AIN93G diet for two weeks. At five weeks of age, the KC mice were randomly assigned to either a control diet (CD) group (12% calories from fat with an omega-6:omega-3 FA ratio of 10:1) or a diet induced obesity (DIO) group (60% calories from fat with an omega-6:omega-3 FA ratio of 10:1) and fed their respective diets until three months of age. Mice were euthanized and organs and serum were collected for further analysis. Results: After 7 weeks on their respective diets, DIO-fed mice had higher body weight compared to CD-fed mice; however, it only reached statistically significance in female mice. Male and female DIO-fed mice had significantly higher fat mass, and significantly lower lean, compared to CD-fed mice. Additionally, male, but not female, DIO-fed mice had a significantly larger pancreas’ weight compared to CD-fed mice. Moreover, upon histological analysis, DIO-fed mice had a significantly increased rate of acinar-to-ductal metaplasia, compared to CD-fed mice. In addition, there were high serum concentrations of leptin, insulin as well as the pro-inflammatory cytokines IL-6, and TNF-α in KC mice fed a DIO compared to the CD-fed mice. In contrast, no differences were noted in MCP-1 and IL-1β between groups. Conclusion: Our results indicate that feeding a high-fat diet (mimicking a Western-style diet) for 7 weeks leads to increased body fatness, acinar-to-ductal metaplasia, and increased levels of leptin, insulin and pro-inflammatory cytokines. Current work is underway to characterize the cellular mechanisms on how DIO induces pancreatic carcinogenesis, as well as the specific roles played by select FA in pancreatic carcinogenesis. Citation Format: Aya Ead, Joanna Wirkus, Gerardo G. Mackenzie. A Western-style mimicking high-fat diet increases early stage pancreatic carcinogenesis in a KC murine model [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer; 2022 Sep 13-16; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2022;82(22 Suppl):Abstract nr A065.

Abstract B061: Identification of cell identity pathways that cooperate with oncogenic Kras in pancreatic cancer initiation by single-cell epigenomic analysis

Abstract Background: The major genetic driver for pancreatic ductal adenocarcinoma (PDAC) is oncogenic KRAS. However, adult acinar cells, a probable origin of PDAC, are largely refractory to KrasG12D-mediated oncogenic transformation in mouse models. With the concomitant loss of transcription factors that regulate acinar cell differentiation, such as Pdx1 (Pancreatic and Duodenal Homeobox 1), acinar cells undergo a rapid cell identity switch, known as acinar-to-ductal metaplasia (ADM). Consequently, KrasG12D;Pdx1f/f (Pdx1 knockout) mice present with massively accelerated tumor formation. How loss of cell identity cooperates with oncogenic Kras to induce pancreatic transformation is largely unclear. Methods: To elucidate mechanisms responsible for the accelerated cellular reprogramming in KrasG12D;Pdx1f/f animals, single-cell ATAC-seq (Assay for Transposase-Accessible Chromatin using sequencing) from frozen pancreatic bulk tissue was performed. Chromatin accessibility states were captured at early stages of carcinogenesis (two and ten weeks after CreERT-induced recombination) and compared to those of KrasG12D and CreERT control animals. Changes in the epigenome were correlated to RNA-seq data. Expression of differentially regulated genes was validated by RNAscope and immunohistochemistry staining. The role of identified target genes was studied in pancreatic cancer cell lines. Results: Single-cell ATAC-seq proved as a very powerful and robust tool for defining cell-type identity, cellular reprogramming and target genes in early metaplastic transformation of pancreatic tissue. By analyzing tissue of KrasG12D;Pdx1f/f mice at different time points, we captured the complete metaplastic conversion of acinar cells into ADM and different subsets of precancerous lesions. Despite initially appearing phenotypically normal, the chromatin profiles of Pdx1 knockout acinar cells showed a striking similarity to ADM cells. Interestingly, acinar and ADM cells of KrasG12D;Pdx1f/f animals as well as ADM lesions of KrasG12D mice showed elevated accessibility and expression of the Ror2 gene. As a receptor protein tyrosine kinase, Ror2 regulates essential signaling pathways, such as Ras-MAPK signaling. Immunostaining of pancreatic cancer tissues from KrasG12D;p53mut (KPC) mice and human PDAC specimens also revealed Ror2 expression in a subset of neoplasms and cancer cells. Knockdown of Ror2 in pancreatic cancer cell lines with a basal-like subtype significantly decreased cell proliferation and expression of cell cycle regulators, while ectopic overexpression in PDAC lines with a classical differentiation induced a dramatic change in cell identity and massively increased cell proliferation. Conclusions: Our in-depth sequencing data revealed that expression of KrasG12D with the concomitant loss of Pdx1 lead to vast alterations of acinar cell identity and significantly accelerated transformation. We identified de-regulation of the receptor kinase Ror2, which cooperates with KrasG12D to induce and promote pancreatic carcinogenesis and proliferation. Citation Format: Simone Benitz, Ian Loveless, Malak Nasser, Hui-Ju Wen, Daniel Long, Erick Davis, Jacee Moore, Tobias Straub, Ivonne Regel, Filip Bednar, Howard Crawford. Identification of cell identity pathways that cooperate with oncogenic Kras in pancreatic cancer initiation by single-cell epigenomic analysis [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer; 2022 Sep 13-16; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2022;82(22 Suppl):Abstract nr B061.

Mechanism of Resveratrol-Induced Programmed Cell Death and New Drug Discovery against Cancer: A Review.

Resveratrol (3,5,4'-trihydroxy-trans-stilbene), a polyphenol found in grapes, red wine, peanuts, and apples, has been reported to exhibit a wide range of biological and pharmacological properties. In addition, resveratrol has been reported to intervene in multiple stages of carcinogenesis. It has also been known to kill several human cancer cells through programmed cell death (PCD) mechanisms such as apoptosis, autophagy, and necroptosis. However, resveratrol has limitations in its use as an anticancer agent because it is susceptible to photoisomerization owing to its unstable double bond, short half-life, and is rapidly metabolized and eliminated. Trans-(E)-resveratrol is nontoxic, and has several biological and pharmacological activities. However, little is known about the pharmacological properties of the photoisomerized cis-(Z)-resveratrol. Therefore, many studies on resveratrol derivatives and analogues that can overcome the shortcomings of resveratrol and increase its anticancer activity are underway. This review comprehensively summarizes the literature related to resveratrol-induced PCD, such as apoptosis, autophagy, necroptosis, and the development status of synthetic resveratrol derivatives and analogues as novel anticancer drugs.

MiR-450b promotes cell migration and invasion by inhibiting SERPINB2 in oral squamous cell carcinoma.

microRNA-450b (miR-450b) plays an important role in cancer progression; however, its function in oral squamous cell carcinoma (OSCC) remains largely unknown. This study aimed to investigate the action mechanisms of miR-450b in OSCC. OSCC animal model was established via continuous induction with single-drug 7, 12-dimethylbenzo[a]anthracene (DMBA). Animal tissue samples were pathologically typed using haematoxylin-eosin (HE) staining. The Cancer Genome Atlas (TCGA) database was used to predict miR-450b and SERPINB2 expression in head and neck squamous cell carcinoma (HNSCC). qRT-PCR and Western blotting were used to detect gene and protein expression in OSCC tissue and cells, respectively. OSCC cell proliferation, growth, migration and invasion were detected using CCK-8, colony formation, transwell migration and matrigel invasion assays, respectively. Bioinformatic tools were used to predict miR-450b target genes. Dual-luciferase reporter assay was used to verify targeting between miR-450b and SERPINB2. Finally, small interfering RNA (siRNA) was used to reduce SERPINB2 expression to detect its effect on tumourigenesis. Four stages of OSCC carcinogenesis (normal oral epithelium, simple epithelial hyperplasia, dysplasia and OSCC) were identified. miR-450b was found to be overexpressed in OSCC animal samples, HNSCC samples and human OSCC cells. Upregulation of miR-450b significantly promoted OSCC cell proliferation, colony formation, migration and invasion, while its downregulation had the opposite effect. SERPINB2 was found to be a miR-450b target gene, and its expression was negatively correlated with miR-450b expression. Altering SERPINB2 expression effectively inhibited OSCC cell invasion, metastasis and epithelial-mesenchymal transition (EMT). miR-450b plays a key role in OSCC tumourigenesis by regulating OSCC cell migration, invasion and EMT via SERPINB2.

Common Germline Risk Variants Impact Somatic Alterations and Clinical Features across Cancers.

Meta-analyses across cancers show that common germline risk variants affect not only cancer predisposition but the age of cancer onset and burden of somatic alterations, including total mutations and copy-number alterations.

Targeting Transcription Factors in Cancer: From "Undruggable" to "Druggable".

Deregulation of transcription factors is critical to hallmarks of cancer. Genetic mutations, gene fusions, amplifications or deletions, epigenetic alternations, and aberrant post-transcriptional modification of transcription factors are involved in the regulation of various stages of carcinogenesis, including cancer initiation, progression, and metastasis. Thus, targeting the dysfunctional transcription factors may lead to new cancer therapeutic strategies. However, transcription factors are conventionally considered as "undruggable." Here, we summarize the recent progresses in understanding the regulation of transcription factors in cancers and strategies to target transcription factors and co-factors for preclinical and clinical drug development, particularly focusing on c-Myc, YAP/TAZ, and β-catenin due to their significance and interplays in cancer.

High co-expression of immune checkpoint receptors PD-1, CTLA-4, LAG-3, TIM-3, and TIGIT on tumor-infiltrating lymphocytes in early-stage breast cancer

High expression of immune checkpoint receptors (ICRs) in the tumor microenvironment regulates the anti-tumor response. In this study, the differential expressions of ICRs on tumor-infiltrating lymphocytes (TILs) in patients with early-stage breast cancer were investigated.The study included 32 patients who underwent surgery with a diagnosis of early-stage breast cancer between September 2018 and March 2020. TIL isolation was performed using a MACS tumor separation device and tumor separation kit. PD-1, CTLA-4, LAG-3, TIM-3, and TIGIT expression of cytotoxic T and natural killer (NK) cells on TILs and peripheral blood lymphocytes (PBLs) were determined by flow cytometry.Patients with a high Ki-67 index, high TIL density, and HER-2 positivity were more likely to have increased CD16+CD56dim NK cells on TILs. Patients with T2 tumors were more likely to have increased expression of PD-1, LAG-3, and TIGIT on tumor-infiltrating CD8+ cytotoxic T cells than those with T1 tumors. PD-1, CTLA-4, TIGIT, LAG-3, and TIM-3 expression of CD8+ T and CD16-CD56bright NK cells in TILs showed significant positive correlations with each other. PD1+CD8+, TIGIT+CD16+, and CTLA-4+CD56+ cells in PBLs and TILs were found to be negatively correlated, whereas only TIM-3+ expression of CD8+ T and CD16+CD56dim cells in PBLs and TILs showed positive correlations.Our results suggest that CD16+CD56dim NK cells on TILs may play a major role in the immune response against HER2-positive or highly proliferating breast tumors in patients with early-stage breast cancer. Furthermore, various ICRs were found to be highly co-expressed with each other on TILs, including PD-1, CTLA-4, LAG-3, TIM-3, and TIGIT. These receptors may synergistically suppress the response to the tumor, which may trigger immune escape mechanisms in the early stage of carcinogenesis. However, ICR expressions other than TIM3 on PBLs were not found to accompany their counterparts on TILs.

P53 mutation in normal esophagus promotes multiple stages of carcinogenesis but is constrained by clonal competition

Aging normal human oesophagus accumulates TP53 mutant clones. These are the origin of most oesophageal squamous carcinomas, in which biallelic TP53 disruption is almost universal. However, how p53 mutant clones expand and contribute to cancer development is unclear. Here we show that inducing the p53R245W mutant in single oesophageal progenitor cells in transgenic mice confers a proliferative advantage and clonal expansion but does not disrupt normal epithelial structure. Loss of the remaining p53 allele in mutant cells results in genomically unstable p53R245W/null epithelium with giant polyaneuploid cells and copy number altered clones. In carcinogenesis, p53 mutation does not initiate tumour formation, but tumours developing from areas with p53 mutation and LOH are larger and show extensive chromosomal instability compared to lesions arising in wild type epithelium. We conclude that p53 has distinct functions at different stages of carcinogenesis and that LOH within p53 mutant clones in normal epithelium is a critical step in malignant transformation.