Precancerous Cells Research Articles

Fat body-derived Spz5 remotely facilitates tumor-suppressive cell competition through Toll-6-α-Spectrin axis-mediated Hippo activation.

Tumor-suppressive cell competition is an evolutionarily conserved process that selectively removes precancerous cells to maintain tissue homeostasis. Using the polarity-deficiency-induced cell competition model in Drosophila, we identify Toll-6, a Toll-like receptor family member, as a driver of tension-mediated cell competition through α-Spectrin (α-Spec)-Yorkie (Yki) cascade. Toll-6 aggregates along the boundary between wild-type and polarity-deficient clones, where Toll-6 physically interacts with the cytoskeleton network protein α-Spec to increase mechanical tension, resulting in actomyosin-dependent Hippo pathway activation and the elimination of scrib mutant cells. Furthermore, we show that Spz5 secreted from fat body, the key innate organ in fly, facilitates the elimination of scrib clones by binding to Toll-6. These findings uncover mechanisms by which fat bodies remotely regulate tumor-suppressive cell competition of polarity-deficient tumors through inter-organ crosstalk and identified the Toll-6-α-Spec axis as an essential guardian that prevents tumorigenesis via tension-mediated cell elimination.

A review of biologically active flavonoids as inducers of autophagy and apoptosis in neoplastic cells and as cytoprotective agents in non‐neoplastic cells

Phytochemicals are a diverse group of compounds found in various fruits, vegetables, nuts, and legumes. Many phytochemicals have been observed to possess health benefits. Some have been found to be chemoprotective or can act as chemotherapeutics by inducing autophagy, apoptosis, or otherwise regulating the cell cycle. Many also act as potent antioxidants. Flavonoids are a subclass of bioactive phytochemicals consisting of two phenolic benzene rings, joined together by a heterocyclic pyran or pyrone. It has been observed in multiple studies that there is a correlation between diets rich in flavonoids and a reduction in cancer levels, heart disease, neurodegenerative diseases, and other pathologies. As foods containing flavonoids are widely consumed, and their mechanisms of action are still only partially understood, this review was compiled to compare the effects and mechanisms of action of some of the most widely characterized and publicized flavonoids. The flavonoids silibinin, quercetin, isorhamnetin, luteolin, curcumin genkwanin, and acacetin, together with flavonoid extracts from papaw and Tephroseris kirilowii (Turcz) Holub, a member of the Daisy family, were found to be potent regulators of the cell cycle. The decision to overview these specific flavonoids was based on their therapeutic effects, and/or their potential effects. The sparsity of data comparing these flavonoids was also a key consideration. These flavonoids all modulated to some extent the pathways of autophagy and/or apoptosis and regulated the cell cycle, inflammation, and free radical levels. This explains why they are protective of healthy or moderately damaged cells, but toxic to neoplastic or pre-cancerous cells.

Age-structured Delayed SIPCV Epidemic Model of HPV and Cervical Cancer Cells Dynamics II. Convergence of Numerical Solution

The numerical method for simulation of age-structured SIPCV epidemic model with age-structured sub-classes of susceptible, infectious, precancerous and cancer cells and unstructured population of human papilloma virus (HPV) dynamics with incubation period is developed. Convergence of the numerical approximations is studied both theoretically and numerically. We prove the stability and second rate of convergence of the approximate solutions to the exact solution of the SIPCV epidemic nonlinear system. The numerical experiments based on the grid refined method confirm and illustrate the second order of accuracy of the obtained numerical method and show the various dynamical regimes of population dynamics. Simulations for model parameters of the system reveal two unstable dynamical regimes of SIPCV population which correspond to the cancer tumor growth and formation of metastases in organism.

Influence of ionizing radiation and cell density on the kinetics of autocrine destruction and intercellular induction of apoptosis in precancerous cells

Intercellular induction of apoptosis (IIA) represents a well-defined signaling model by which precancerous cells are selectively eradicated through reactive oxygen/nitrogen species and cytokine signaling from neighbour normal cells. Previously, we demonstrated that the IIA process could be enhanced by exposure of normal cells to very low doses of ionizing radiation as a result of perturbing the intercellular signaling. In this study, we investigate the kinetic behaviour of both autocrine destruction (AD) and IIA as a function of cell density of both precancerous and normal cells using an insert co-culture system and how exposure of normal cells to ionizing radiation influence the kinetics of apoptosis induction in precancerous cells. Increasing the seeding density of transformed cells shifts the kinetics of AD towards earlier times with the response plateauing only at high seeding densities. Likewise, when co-culturing precancerous cells with normal cells, increasing the seeding density of either normal or precancerous cells also shifts the kinetics of IIA response towards earlier times and plateau only at higher seeding densities. Irradiation of normal cells prior to co-culture further enhances the kinetics of IIA response, with the degree of enhancement dependent on the relative cell densities. These results demonstrate the pivotal role of the cell seeding density of normal and precancerous cells in modulating both AD and IIA. These results further support the proposition that ionizing radiation could result in an enhancement in the rate of removal of precancerous cells through the IIA process.

Genomic and transcriptomic somatic alterations of hepatocellular carcinoma in non-cirrhotic livers

Genomic and transcriptomic somatic alterations of hepatocellular carcinoma in non-cirrhotic livers

Evidence of a role for interleukin-6 in anoikis resistance in oral squamous cell carcinoma

In an endeavour to understand metastasis from oral squamous cell carcinomas, we characterised the metastatic potential of a human tongue derived cell line (SCC-4 cells) and compared this phenotype to pre-cancerous dysplastic oral keratinocyte (DOK) cells derived from human tongue and primary gingival keratinocytes (PGK). We demonstrate that SCC-4 cells constitutively synthesize and release significant amounts of IL-6, a process that is enhanced by the addition of the TLR2/TLR6 agonist, Pam2CSK4. The expression of TLR2/6 and IL-6Ra/gp130 receptors was also confirmed in SCC-4 cells. Cancerous SCC-4 human tongue cells also have a classic EMT profile, unlike precancerous human tongue DOK cells. We also established that IL-6 is driving anoikis resistance in an autocrine fashion and that anti-IL-6 neutralising antibodies, anti-IL-6 receptor antibodies and anti-TLR2 receptor antibodies inhibit anoikis resistance in cancerous SCC-4 human tongue cells. The data suggest a promising role for anti-IL-6 receptor antibody and anti-TLR2 receptor antibody treatment for oral cancer.

Role of human papillomavirus (HPV) in the development of skin cancer

The incidence of nonmelanoma skin cancer, the most common cancer in humans, continues to rise. The development of precancerous actinic keratoses and cutaneous squamous cell carcinoma (cSCC) is associated with infection with human papillomavirus (HPV) of genus beta (betaHPV). Persistent betaHPV infections in immunocompetent individuals are generally very well controlled by the immune system and largely asymptomatic. However, immunosuppression results in high levels of betaHPV in the skin and consequently increased viral oncoprotein activity, which in turn leads to asignificantly increased risk for skin cancer. However, even in immunocompetent individuals, the risk of cSCC increases with age as aresult of accumulated UV-induced DNA damage in the skin. In these patients, the mechanism of betaHPV-dependent carcinogenesis seems to be different from that observed in immunocompromised patients. The underlying mechanism of oncogenesis in immunocompetent patients is currently less well understood. This review summarizes the current research data, which provide compelling evidence that cutaneous papillomaviruses, particularly in interaction with UV light, promote skin carcinogenesis via a"hit-and-run" mechanism by enhancing the genotoxic effects of UV light in the initial phases of this multistep process. Furthermore, an overview of novel vaccination strategies against papillomaviruses that are currently tested in clinical trials is provided, which could significantly improve the treatment options for high-risk patients in the future.

A Screening of Native (Poly)phenols and Gut-Related Metabolites on 3D HCT116 Spheroids Reveals Gut Health Benefits of a Flavan-3-ol Metabolite.

Epidemiological evidence suggests that a reduced risk of colorectal cancer (CRC) is correlated with high consumption of fruits and vegetables, which are major sources of fiber and phytochemicals, such as flavan-3-ols. However, it remains unknown how these phytochemicals and their specific gut-related metabolites may alter cancer cell behavior. A focused screening using native (poly)phenols and gut microbial metabolites (GMMs) on 3D HCT116 spheroids is carried out using a high-throughput imaging approach. Dose-responses, IC50 , and long-term exposure are calculated for the most promising native (poly)phenols and GMMs. As a result, this research shows that (poly)phenol catabolites may play a key role in preventing cancer propagation. Indeed, µM concentration levels of (4R)-5-(3',4'-dihydroxyphenyl)-γ-valerolactone significantly decrease spheroid size at early stages of spheroid aggregation and gene expression of matrix metalloproteinases. A chronic exposure to (4R)-5-(3',4'-dihydroxyphenyl)-γ-valerolactone may lead to a reduced CRC risk. Daily intake of monomeric, oligomeric, and polymeric flavan-3-ols may increase the colonic concentrations of this metabolite, and, in turn, this compound may act locally interacting with intestinal epithelial cells, precancerous and cancer cells.

Profiling of Oral Cells Morphology by means of a novel Label-Free Method of Polarization Diffraction Imaging

Currently, all oral leukoplakias, per gold standard, should undergo microscopic examination for diagnosis, which is an invasive procedure, and many patients are resistant to it due to cost, fear, or aversion to pain. We plan to develop a non-invasive assay, by using polarization diffraction imaging flow cytometry (p-DIFC) which is a technique that renders a three-dimensional model of single cells. That acquires a cross-polarized diffraction image pair (p-DI) of the coherent light scattered by a single cell with high image contrast excited by a linearly polarized laser beam. This method of single-cell assay enables extraction of cell morphology related information from the diffraction patterns embedded in the p-DI pair for each individual cell. In addition, the team has developed an optical model of cells based on confocal imaging to simulate the coherent light scattering process of a cell and convert the spatial distribution of scattered light into calculated p-DI pairs. Objectives: We aim to develop a protocol for acquiring oral mucosal cells for confocal imaging and establishing their individual three-dimensional (3D) morphologic profiles in the form of a preliminary database. In Phase 2, we will establish correlations between diffraction patterns from calculated p-DI data and the morphologic features revealed by mi- croscopy. Methods: We are collecting and quantifying individual cells from oral mucosa, in order to set a quantitative 3D morphologic single-cell parameter by confocal microscopy, for modeling study of diffraction patterns. Phase 2 of the study will involve single-cell analysis using p-DIFC for identification of early malignant changes in cytological sampling of mucosal lesions suspicious for malignancy. Conclusions: The results of this ongoing investigation will lay the foundation for future non-invasive, label-free detection of precancerous cells during intraoral examination, by investigating the profiling of cells harvested from patients in our institutions.

Circular RNA LONP2 regulates proliferation, invasion, and apoptosis of bladder cancer cells by sponging microRNA-584-5p

ABSTRACT Bladder cancer (BC) is the most frequent type of urinary tumor and a barely treatable disease. Although extensive efforts have been invested in the research of BC, the underlying etiology and pathophysiology remain unclear. CircLONP2 is a circular RNA implicated in the development of many cancers, and miR-584-5p and YAP1 have been reported to contribute to the progression of BC. In this research, we presented novel evidence supporting circLONP2/miR-584-5p/YAP1 axis as a novel regulatory module in the progression of BC. We analyzed the expression of circLONP2 between precancerous BC samples and normal tissues using a published RNA-seq dataset. The expression of circLONP2 was also validated in clinical samples and cell lines by quantitative RT-PCR. Small interfering RNA (siRNA) and miRNA inhibitor was utilized to modulate the expression of circLONP2 and miR-584-5p and investigate their functions on cell proliferation and invasion. Luciferase reporter assay and RNA pull-down were performed to confirm the functional interactions among circLONP2/miR-584-5p/YAP1. CircLONP2 was significantly upregulated in precancerous BC tissues and BC cells. CircLONP2 depletion inhibited cell viability, proliferation, and invasion of BC cell lines, which could be partially rescued by miR-584-5p inhibitor. Further experiments indicated that miR-584-5p regulates cell viability, proliferation, and invasion via directly targeting YAP1. In summary, our work indicates that circLONP2 plays an oncogenic function in BC by regulating miR-584-5p/YAP1 axis, and its interaction with miR-584-5p provides a potential strategy to target BC.

Chemopreventive efficacy of salvianolic acid B phospholipid complex loaded nanoparticles against experimental oral carcinogenesis: implication of sustained drug release.

BackgroundAlthough we have previously demonstrated that phospholipid complex loaded nanoparticles (PLC-NPs) encapsulating salvianolic acid B (SAB) can enhance anticancer activity in head and neck cancer and precancerous cells in vitro, the chemopreventive efficacy of SAB-PLC-NPs (nano-SAB) in vivo remains unclear. Here, we aimed to investigate the in vivo efficacy of nano-SAB against experimental oral carcinogenesis.MethodsOral tongue carcinogenesis was induced in C57BL/6 mice through the administration of 4-nitroquinoline-N-oxide (4NQO, 100 µg/mL) in drinking water for 22 weeks. To preliminarily evaluate the effect of sustained drug release against oral carcinogenesis, free- or nano-SAB (16.6 mg/kg/d) was administered orally for 18 weeks, and the treatment was discontinued for the remaining 4 weeks.ResultsHistological evaluation revealed a significant (P<0.05) decrease in the incidence of carcinoma in free-SAB-treated (16.7%) and nano-SAB-treated (10.0%) mice compared to mice exposed to 4NQO alone (34.3%). A decrease in carcinoma growth rate was also observed in free-SAB-treated (12.2%) and nano-SAB-treated (5.5%) mice compared to the 4NQO-exposed group (18.3%), even after drug withdrawal for 4 weeks. Immunohistochemical analysis revealed that nano-SAB treatment effectively suppressed Ki-67, proliferative cell nuclear antigen (PCNA), and cyclin D1 expression in high-risk dysplastic lesions compared to free-SAB-treated and 4NQO-exposed groups (all P<0.05). Importantly, nano-SAB maintained low levels of Ki-67, PCNA, and cyclin D1 expression even after drug withdrawal for 4 weeks.ConclusionsTogether with our previous in vitro data, this in vivo study confirms that nano-SAB has superior chemopreventive efficacy by promoting more potent anti-proliferation and cell cycle arrest responses. These findings demonstrate the potential of SAB-PLC-NPs as promising chemopreventive agents for treating oral carcinogenesis.

MHC class I-LILRB3 delivers a punch to eliminate precancerous cells.

MHC class I-LILRB3 delivers a punch to eliminate precancerous cells.

Autophagy modulation by viruses: An important role in tumor progression

Autophagy is an important process for cellular homeostasis at critical steps of development or in response to environmental stress. In the context of cancers, autophagy has a significant impact on tumor occurrence and tumor cell growth. On the one hand, autophagy limits the transformation of precancerous cells into cancer cells at an early stage. However, on the other hand, it promotes cell survival, cell proliferation, metastasis and resistance to anti-tumor therapies in more advanced tumors. Autophagy can be induced by a variety of extracellular and intracellular stimulus. Viral infections have often been associated with a modulation of autophagy, with variable impacts on viral replication and on the survival of infected cells depending on the model studied. In a tumor context, the modulation of autophagy induced by the viral infection of tumor cells seems to have a significant impact on tumor progression. The aim of this review article is to present recent findings regarding the consequences of autophagy disturbance by viral infections on tumor behavior.

Accounting for dimensional differences in stochastic domain invasion with applications to precancerous cell removal

We consider a specific form of domain invasion that is an abstraction of pancreatic tissue eliminating precancerous mutant cells through juxtacrine signalling. The model is explored discretely, continuously, stochastically and deterministically, highlighting unforeseen nonlinear dependencies on the dimension of the solution domain. Specifically, stochastically simulated populations invade with a dimension dependent wave speed that can be over twice as fast as their deterministic analogues. Although the wave speed can be analytically derived in the cases of small domains, the probabilistic state space grows exponentially and, thus, we use numeric simulation and curve fitting to predict limiting dynamics.

R-Loop-Associated Genomic Instability and Implication of WRN and WRNIP1.

Maintenance of genome stability is crucial for cell survival and relies on accurate DNA replication. However, replication fork progression is under constant attack from different exogenous and endogenous factors that can give rise to replication stress, a source of genomic instability and a notable hallmark of pre-cancerous and cancerous cells. Notably, one of the major natural threats for DNA replication is transcription. Encounters or conflicts between replication and transcription are unavoidable, as they compete for the same DNA template, so that collisions occur quite frequently. The main harmful transcription-associated structures are R-loops. These are DNA structures consisting of a DNA–RNA hybrid and a displaced single-stranded DNA, which play important physiological roles. However, if their homeostasis is altered, they become a potent source of replication stress and genome instability giving rise to several human diseases, including cancer. To combat the deleterious consequences of pathological R-loop persistence, cells have evolved multiple mechanisms, and an ever growing number of replication fork protection factors have been implicated in preventing/removing these harmful structures; however, many others are perhaps still unknown. In this review, we report the current knowledge on how aberrant R-loops affect genome integrity and how they are handled, and we discuss our recent findings on the role played by two fork protection factors, the Werner syndrome protein (WRN) and the Werner helicase-interacting protein 1 (WRNIP1) in response to R-loop-induced genome instability.

Mathematical analysis of a SIPC age-structured model of cervical cancer.

Human Papillomavirus (HPV), which is the main causal factor of cervical cancer, infects normal cervical cells on the specific cell's age interval, i.e., between the G1 to S phase of cell cycle. Hence, the spread of the viruses in cervical tissue not only depends on the time, but also the cell age. By this fact, we introduce a new model that shows the spread of HPV infections on the cervical tissue by considering the age of cells and the time. The model is a four dimensional system of the first order partial differential equations with time and age independent variables, where the cells population is divided into four sub-populations, i.e., susceptible cells, infected cells by HPV, precancerous cells, and cancer cells. There are two types of the steady state solution of the system, i.e., disease-free and cancerous steady state solutions, where the stability is determined by using Fatou's lemma and solving some integral equations. In this case, we use a non-standard method to calculate the basic reproduction number of the system. Lastly, we use numerical simulations to show the dynamics of the age-structured system.

Human Adipose Stem Cells Exposed to Gamma Radiation and Inactivity (Stasis) Show Increased Cancer Markers and DNA Damage. A Preliminary Assessment of a Pharmaceutical Formulation to Reverse These Effects and Its Applications for Medical Radiotherapy and the Space Industry

Gamma radiation exposure and physical inactivity occur in medical radiotherapy patients and astronauts resulting in substantial deterioration of their health. At the molecular level, the radiation triggers elevated markers for DNA double-strand breaks and tumorigenicity. Cell stasis is a potential phenomenon associated with low physical activity in recovering cancer patients and astronauts. This preliminary study assessed parameters of stasis and gamma radiation on human adipose stem cells (ADSCs) that have important regenerative functions for the body. A prototype pharmaceutical formulation (PF) was tested to prevent and reverse the effects of radiation and stasis. ADSCs were subjected to short-term (1 - 5 days) and longer-term (8 - 25 days) stasis and radiation with a combined total exposure of alpha, beta and gamma radiation measured at 455 microSv/hr on the Geiger counter. Cell health markers were grouped for characteristics of cellular health (annexin, H2A.X, NO, ROS) and tumorigenicity potential (P13, Ki67, MAPK) that were measured with flow cytometry. Results showed PF to improve cell health in days 1 - 5 compared to stasis (p = 0.01) and radiation (p = 0.02), and PF reduced tumorigenicity compared with stasis (p = 0.018) and radiation (p = 0.03). For longer exposure (8 - 25 days) PF improved cellular health compared with stasis (p = 0.038) and showed a non-significant trend for decreasing radiation effects (p = 0.07). There was decreased tumorigenicity compared with stasis (p = 0.003) and radiation (p = 0.005). This preliminary evaluation of the PF showed it to have 88% (66/75) positive assay results (p < 0.00001 Chi-square) indicating three promising beneficial effects: 1) prevent cell/DNA damage, 2) reduce cancer risk, and 3) recover damaged and precancerous stem cells. The PF could have important applications for medical radiotherapy patients, astronauts and future space mining personnel. PF reduced carcinogenesis and DNA damage of stem cells by approximately 50% from radiation that was the microSievert equivalent of 4 months on board the International Space Station.

Thermal Ablation Treatment for Cervical Precancer (Cervical Intraepithelial Neoplasia Grade 2 or Higher [CIN2+]).

Cervical cancer is a leading cause of mortality for women in low- and middle-income countries (LMICs). Invasive disease can be prevented through the treatment of high-grade cervical precancer lesions. Types of treatment for cervical precancer include excisional procedures that surgically remove the affected tissue and ablation treatments which utilize extreme temperatures to destroy precancerous cells. Excision is the first-line treatment in higher income countries, but requires specialized training and equipment that make it unsuitable for low-income settings. The most common treatment globally is cryotherapy, which utilizes cryogenic gas to freeze the area. However, the need for gas presents significant procurement and logistical challenges. The World Health Organization (WHO) has recently endorsed the use of thermal ablation, a method that utilizes heat to destroy precancerous tissue. This review describes three existing thermal ablation devices and protocols for their use, including step-by-step instruction guides to perform a successful treatment with each device and observations specific to each machine.

Prophylactic vaccines against cancers of non-infectious origin: a dream or a real possibility?

The dramatic progress in tumour biology and immunology in the past several years has opened new avenues for the treatment and prevention of cancer. One of the great contributions of the immunotherapeutic approaches is an increasing understanding of the immunology of cancer, which is, gradually creating conditions for the development of prophylactic anti-cancer vaccines. Efficient vaccines have been developed and employed for the prophylaxis of two frequent cancers of viral origin, namely cervical cancer and liver cancer. The new knowledge on the interactions between the immune system and the malignant tumors seems to provide means for the development of prophylactic vaccines against cancers developing due to the mutations in the proto-oncogenes converting their products into oncoproteins. According to the present estimates, these cancers form a great majority of human malignancies. Recent evidence has indicated that the immune system recognizes such mutated proteins, and that the development of cancer is due to the failure of the immune system to eliminate neoplastic cells. Followingly, it can be expected that inducing immunity against the mutated epitopes will increase the capacity of the body to deal with the initiated precancerous cells. In the present paper this hypothesis is primarily discussed in the relationship with colorectal cancer (CRC), which seems to be a well-fitting candidate for prophylactic vaccination. CRC is the third most frequent malignancy and the fourth most common cause of cancer mortality. Mutations of two proto-oncogenes, namely RAS and RAF, are involved in the majority of CRC cases and, in addition, they are shared with other human malignancies. Therefore, the strategy to be used for prophylaxis of CRC is discussed together with several other frequent human cancers, namely lung cancer, pancreatic duct cancer and melanoma. The prophylactic vaccines proposed are aimed at the reduction of the incidence of these and, to a lesser extent, some other cancers.

Epigenetic priming in chronic liver disease impacts the transcriptional and genetic landscapes of hepatocellular carcinoma.

Hepatocellular carcinomas (HCCs) usually arise from chronic liver disease (CLD). Precancerous cells in chronically inflamed environments may be ‘epigenetically primed’, sensitising them to oncogenic transformation. We investigated whether epigenetic priming in CLD may affect HCC outcomes by influencing the genomic and transcriptomic landscapes of HCC. Analysis of DNA methylation arrays from 10 paired CLD‐HCC identified 339 shared dysregulated CpG sites and 18 shared differentially methylated regions compared with healthy livers. These regions were associated with dysregulated expression of genes with relevance in HCC, including ubiquitin D (UBD), cytochrome P450 family 2 subfamily C member 19 (CYP2C19) and O‐6‐methylguanine‐DNA methyltransferase (MGMT). Methylation changes were recapitulated in an independent cohort of nine paired CLD‐HCC. High CLD methylation score, defined using the 124 dysregulated CpGs in CLD and HCC in both cohorts, was associated with poor survival, increased somatic genetic alterations and TP53 mutations in two independent HCC cohorts. Oncogenic transcriptional and methylation dysregulation is evident in CLD and compounded in HCC. Epigenetic priming in CLD sculpts the transcriptional landscape of HCC and creates an environment favouring the acquisition of genetic alterations, suggesting that the extent of epigenetic priming in CLD could influence disease outcome.