The prognostic effect of PTEN expression status in colorectal cancer development and evaluation of factors affecting it: miR-21 and promoter methylation

Kolmogorov-Arnold Network Model Integrated with Hypoxia Risk for Predicting PD-L1 Inhibitor Responses in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is a leading cause of cancer-related deaths, with immunotherapy being a first-line treatment at the advanced stage and beyond. Hypoxia plays a critical role in tumor progression and resistance to therapy. This study develops and validates an artificial intelligence (AI) model based on publicly available genomic datasets to predict hypoxia-related immunotherapy responses. Based on the HCC-Hypoxia Overlap (HHO) and immunotherapy response to hypoxia (IRH) genes selected by differential expression and enrichment analyses, a hypoxia model was built and validated on the TCGA-LIHC and GSE233802 datasets, respectively. The training and test sets were assembled from the EGAD00001008128 dataset of 290 HCC patients, and the response and non-response classes were balanced using the Synthetic Minority Over-sampling Technique. With the genes selected via the minimum Redundancy Maximum Relevance and stepwise forward methods, a Kolmogorov-Arnold Network (KAN) model was trained. Support Vector Machine (SVM) combined the Hypoxia and KAN models to predict immunotherapy response. The hypoxia model was constructed using 10 genes (IRH and HHO). The KAN model with 11 genes achieved a test accuracy of 0.7. The SVM integrating the hypoxia and KAN models achieved a test accuracy of 0.725. The established AI model can predict immunotherapy response based on hypoxia risk and genomic factors potentially intervenable in HCC patients.

Oral microbiota: the overlooked catalyst in cancer initiation and progression

The advancement of high-throughput sequencing technology in recent decades has led to a greater understanding of the components of the oral microbiota, providing a solid foundation for extensive research in this field. The oral microbiota plays an important role in an individual's overall health. It has been shown to be significantly correlated with chronic human diseases, including diabetes, rheumatoid arthritis, cardiovascular disease, periodontal disease, and Alzheimer's disease. Furthermore, tumor occurrence and development are closely related to the oral microbiome. Specific bacteria, such as Fusobacterium nucleatum (F. nucleatum), Porphyromonas gingivalis (P. gingivalis), Streptococcus, Streptomyces, Prevotella, and Fibrophagy gingivalis, play critical roles in cancer development. The oral microbiota has various oncogenic mechanisms, including bacterial inflammation, immunological suppression, tumor growth mediated by bacterial toxins, antiapoptotic activity, and carcinogenic effects. This paper reviews the role of the oral microbiota in the occurrence and progression of cancer and systematically elucidates the molecular mechanisms by which dysbiosis influences tumorigenesis and tumor progression. This information can provide a theoretical basis for exploring cancer treatment strategies and offer new insights for cancer prevention.

Semiquantitative assessment of phosphatase and tensin homolog value with immunohistochemistry in colorectal cancer

INTRODUCTION

Colorectal cancer has emerged as a concerning health problem, ranking the third most common form of cancer in both men and women. The phosphatase and tensin homologue (PTEN) protein is widely known for its role as an inhibitor of the phosphatidylinositol 3-kinase/protein kinase-B/mammalian target of rapamycin (PI3K/Akt/mTOR) pathway, playing a major role inhibiting tumor development. Previous studies investigated the role of this protein in the PI3K pathway and how it affected colorectal cancer. However, a standardized cut-off value for PTEN expression has not been established.

METHODS

Immunohistochemistry was used in examining PTEN. The staining grade ranging from 0 to 3 was then multiplied by the number of 100 cancer cells counted, with total score between 0 and 300. In this study, receiver operating characteristic (ROC) curve was employed to determine the expression cut-off value for PTEN in colorectal cancer.

RESULTS

This study showed statistically significant results (P < 0.001) in either tumor or non-tumor tissues by using the ROC curve with a cut-off value of 199.0. This study also revealed significant correlation between nodal status with PTEN (P = 0.008) and stage with PTEN (P = 0.019) with sensitivity 0.753 and specificity 0.728.

CONCLUSION

Semiquantitative assessment with cell counting multiplied by color intensity is a good method in determining PTEN expression. The use of immunohistochemical staining intensity and cell scoring with ROC cut-off is effective to elaborate the effects of PTEN in colorectal cancer (PTEN value > 199.0 was classified as strong and ≤ 199.0 as weak).

Rs12039395 Variant Influences the Expression of hsa-miR-181a-5p and PTEN Toward Colorectal Cancer Risk

BACKGROUND

Single nucleotide polymorphisms (SNPs) in microRNA (miRNA) genes could alter miRNA expression levels or processing and, thus, may contribute to colorectal cancer (CRC) development. Therefore, this study aimed to examine whether the MIR181A1 genomic sequence possesses SNPs that can affect the expression of hsa-miR-181a-5p and, subsequently, impact its targets and associate with CRC risk.

METHODS

The NCBI dbSNP database was searched for possible SNPs associated with MIR181A1. One SNP with a minor allele frequency > 5%, rs12039395 G > T was identified. In silico analyses determined the effect of the SNP on the secondary structure of the miRNA and predicted the hsa-miR-181a-5p target genes. The SNP was genotyped using allelic discrimination assay, the relative hsa-miR-181a-5p expression level was determined using quantitative real-time PCR, and immunohistochemical staining was used to detect target genes in 192 paraffin-embedded specimens collected from 160 CRC patients and 32 healthy subjects.

RESULTS

The rs6505162 SNP conferred protection against CRC, and the G-allele presence provides may provide accessibility for the transcriptional machinery. Hsa-miR-181a-5p was significantly over-expressed in the CRC group compared to controls and in samples carrying the G-allele compared to those with T-allele. PTEN, identified as the only hsa-miR-181a-5p target implicated in CRC, was significantly diminished in the CRC group compared to controls and showed an inverse relationship with hsa-miR-181a-5p expression level as well as negatively associated with the G-allele presence in CRC.

CONCLUSION

This study highlights that rs12039395 G > T may protect against CRC by influencing the expression of hsa-mir-181a-5p and its target gene, PTEN.

Identifying the key hub genes linked with lung squamous cell carcinoma by examining the differentially expressed and survival genes

Lung Squamous Cell Carcinoma is characterised by significant alterations in RNA expression patterns, and a lack of early symptoms and diagnosis results in poor survival rates. Our study aimed to identify the hub genes involved in LUSC by differential expression analysis and their influence on overall survival rates in patients. Thus, identifying genes with the potential to serve as biomarkers and therapeutic targets. RNA sequence data for LUSC was obtained from TCGA and analysed using R Studio. Survival analysis was performed on DE genes. PPI network and hub gene analysis was performed on survival-relevant genes. Enrichment analysis was conducted on the PPI network to elucidate the functional roles of hub genes. Our analysis identified 2774 DEGs in LUSC patient datasets. Survival analysis revealed 511 genes with a significant impact on patient survival. Among these, 20 hub genes-FN1, ACTB, HGF, PDGFRB, PTEN, SNAI1, TGFBR1, ESR1, SERPINE1, THBS1, PDGFRA, VWF, BMP2, LEP, VTN, PXN, ABL1, ITGA3 and ANXA5-were found to have lower expression levels associated with better patient survival, whereas high expression of SOX2 correlated with longer survival. Enrichment analysis indicated that these hub genes are involved in critical cellular and cancer-related pathways. Our study has identified six key hub genes that are differentially expressed and exhibit significant influence over LUSC patient survival outcomes. Further, in vitro and in vivo studies must be conducted on the key genes for their utilisation as therapeutic targets and biomarkers in LUSC.

Prognostic role of immunohistochemical PTEN (phosphatase and tensin homolog) expression and PTEN (rs701848) genotypes among Egyptian patients with different stages of colorectal cancer

Colorectal cancer (CRC) is the third most frequent cancer worldwide and the second major cause of cancer-related death. Thus, we attempted to ascertain the relationship between the genotype and allele frequencies of phosphatase and tensin homolog (PTEN) and immunohistochemical PTEN expression with clinicopathological characteristics in patients with CRC. 150 individuals were allocated into two groups for this cross-sectional randomized case-control study: Group I consisted of 100 patients with histopathologically proven CRC of various stages. Group II: Fifty healthy volunteers. Genetic analysis of PTEN (rs701848 T / C) single nucleotide polymorphism (SNP) was performed using TaqManTM assays and real-time PCR, while PTEN expressions were assessed using immunohistochemical staining. PTN SNP genotypes and alleles did not significantly differ between CRC patients and controls. PTEN expression was lost in 28% of CRC patients, while all healthy controls exhibited PTEN expression. Negative PTEN expression was present in 16 (80%) of stage IV CRC cases, 9 (23.7%) of stage III cases, 3 (37.5%) of stage II cases, and none of stage I cases. It was shown that PTEN expression was weakly positive, moderately positive, and strongly positive in 15, 10, and 9 (respectively) cases of CRC stage I. However, the expression was only weekly positive in 4 (20%) of the patients in stage IV. In the stage IV group, neither moderately nor strongly positive PTEN expressions were found. So, Among Egyptians, the emergence or course of colorectal cancer is unrelated to the PTEN gene mutation. However, the formation and progression of CRC may be influenced by weak or lost PTEN expression.

Genetic Insights into Colorectal Cancer: Evaluating PI3K/AKT Signaling Pathway Genes Expression

The PI3K/AKT pathway plays a pivotal role in cellular processes, and its dysregulation is implicated in various cancers, including colorectal cancer. The present study correlates the expression levels of critical genes (PIK3CA, PTEN, AKT1, FOXO1, and FRAP) in 60 tumor tissues with clinicopathological and demographic characteristics. The results indicate age-related variation in FOXO1 gene expression, with higher levels observed in patients aged 68 and above. In addition, tumors originating from the rectum exhibit higher FOXO1 expression compared to colon tumors, suggesting region-specific differences in expression. The results also identify the potential correlation between PTEN, PIK3CA gene expression, and parameters such as tumor grade and neuroinvasion. The bioinformatic comparative analysis found that PTEN and FOXO1 expressions were downregulated in colorectal cancer tissue compared to normal colon tissue. Relapse-free survival analysis based on gene expression identified significant correlations, highlighting PTEN and FRAP as potential indicators of favorable outcomes. Our findings provide a deeper understanding of the role of the PI3K/AKT pathway in colorectal cancer and the importance of understanding the molecular basis of colorectal cancer development and progression.

Expression of Sailx suchowensis SsIRT9 enhances cadmium accumulation and alters metal homeostasis in tobacco

Cadmium (Cd) contamination in soils is of great concern for plant growth and human health. Willow (Salix spp.) is a promising phytoextractor because of its high biomass production. However, as a non-hyperaccumulator, willow has a low competitive ability in extraction of Cd. Thus, improving Cd concentrations in developing tissues is one of the primary tasks. Here, our study uncovers a novel SsIRT9 gene from Sailx suchowensis which manipulates plant Cd accumulation. SsIRT9 was more highly expressed in willow roots than other SsIRT genes. As a plasma membrane-localized protein, when expressed in yeast, SsIRT9 retarded cell growth more severely than other SsIRT proteins in the presence of Cd. Furthermore, SsIRT9 was cloned and expressed in tobacco and SsIRT9 did not affect plant growth. In hydroponic experiments, SsIRT9 lines displayed higher Cd in the shoots than the wild type. When grown in Cd-contaminated soils, Cd levels in transgenic tobacco increased by 152-364% in roots and by 135-444% in shoots, demonstrating significant superiority in Cd accumulation over other functional IRT/ZIP transporters. Moreover, expressing SsIRT9 in tobacco altered metal homeostasis, especially manganese and zinc. Taken together, we envision that SsIRT9 expression in plants is a promising strategy for upgrading extraction of Cd from soils.

MicroRNA-21's role in PTEN suppression and PI3K/AKT activation: Implications for cancer biology

MicroRNA-21 (miR-21) was recognized as a key figure in the intricate web of tumor biology, with a prominent role in regulating the PTEN tumor suppressor gene and the PI3K/AKT cascade. This review elucidates the multifaceted interactions between miR-21, PTEN, and the PI3K/AKT signaling, shedding light on their profound implications in cancer initiation, progression, and therapeutic strategies. The core of this review delves into the mechanical intricacies of miR-21-mediated PTEN suppression and its consequent impact on PI3K/AKT pathway activation. It explores how miR-21, as an oncogenic miRNA, targets PTEN directly or indirectly, resulting in uncontrolled activation of PI3K/AKT, fostering cancerous cell survival, proliferation, and evasion of apoptosis. Furthermore, the abstract emphasizes the clinical relevance of these molecular interactions, discussing their implications in various cancer types, prognostic significance, and potential as therapeutic targets. The review provides insights into ongoing research efforts to develop miR-21 inhibitors and strategies to restore PTEN function, offering new avenues for cancer treatment. This article illuminates the critical function of miR-21 in PTEN suppression and PI3K/AKT activation, offering profound insights into its implications for cancer biology and the potential for targeted interventions.

Detecting colorectal cancer using genetic and epigenetic biomarkers: screening and diagnosis

Colorectal cancer (CRC) is one of the most frequent types of cancer, with high incidence rates and mortality globally. The extended timeframe for developing CRC allows for the potential screening and early identification of the disease. Furthermore, studies have shown that survival rates for patients with cancer are increased when diagnoses are made at earlier stages. Recent research suggests that the development of CRC, including its precancerous lesion, is influenced not only by genetic factors but also by epigenetic variables. Studies suggest epigenetics plays a significant role in cancer development, particularly CRC. While this approach is still in its early stages and faces challenges due to the variability of CRC, it shows promise as a potential method for understanding and addressing the disease. This review examined the current evidence supporting genetic and epigenetic biomarkers for screening and diagnosis. In addition, we also discussed the feasibility of translating these methodologies into clinical settings. Several markers show promising potential, including the methylation of vimentin (VIM), syndecan-2 (SDC2), and septin 9 (SEPT9). However, their application as screening and diagnostic tools, particularly for early-stage CRC, has not been fully optimized, and their effectiveness needs validation in large, multi-center patient populations. Extensive trials and further investigation are required to translate genetic and epigenetic biomarkers into practical clinical use. biomarkers, diagnostic biomarkers.

The Clinical Significance of MicroRNAs in Colorectal Cancer Signaling Pathways: A Review

Colorectal carcinoma (colon and rectum) is currently considered among the most prevalent malignancies of Western societies. The pathogenesis and etiological mechanisms underlying colorectal cancer (CRC) development remain complex and heterogeneous. The homeostasis and function of normal human intestinal cells is highly regulated by microRNAs. Therefore, it is not surprising that mutations and inactivation of these molecules appear to be linked with progression of colorectal tumors. Recent studies have reported significant alterations of microRNA expression in adenomas and CRCs compared with adjacent normal tissues. This observed deviation has been proposed to correlate with the progression and survival of disease as well as with choice of optimal treatment and drug resistance. MicroRNAs can adopt either oncogenic or tumor-suppressive roles during regulation of pathways that drive carcinogenesis. Typically, oncogenic microRNAs termed oncomirs, target and silence endogenous tumor-suppressor genes. On the other hand, tumor-suppressive microRNAs are critical in downregulating genes associated with cell growth and malignant capabilities. By extensively evaluating robust studies, we have emphasized and distinguished a discrete set of microRNAs that can modulate tumor progression by silencing specific driver genes crucial in signaling pathways including Wnt/b-catenin, epidermal growth factor receptor, P53, mismatch repair DNA repair, and transforming-growth factor beta.

The role of microRNA-21 (miR-21) in pathogenesis, diagnosis, and prognosis of gastrointestinal cancers: A review

MicroRNAs (miRNAs) are small non-coding RNAs regulating the expression of several target genes. miRNAs play a significant role in cancer biology, as they can downregulate their corresponding target genes by impeding the translation of mRNA (at the mRNA level) as well as degrading mRNAs by binding to the 3'-untranslated (UTR) regions (at the protein level). miRNAs may be employed as cancer biomarkers. Therefore, miRNAs are widely investigated for early detection of cancers which can lead to improved survival rates and quality of life. This is particularly important in the case of gastrointestinal cancers, where early detection of the disease could substantially impact patients' survival. MicroRNA-21 (miR-21 or miRNA-21) is one of the most frequently researched miRNAs, where it is involved in the pathophysiology of cancer and the downregulation of several tumor suppressor genes. In gastrointestinal cancers, miR-21 regulates phosphatase and tensin homolog (PTEN), programmed cell death 4 (PDCD4), mothers against decapentaplegic homolog 7 (SMAD7), phosphatidylinositol 3-kinase /protein kinase B (PI3K/AKT), matrix metalloproteinases (MMPs), β-catenin, tropomyosin 1, maspin, and ras homolog gene family member B (RHOB). In this review, we investigate the functions of miR-21 in pathogenesis and its applications as a diagnostic and prognostic cancer biomarker in four different gastrointestinal cancers, including colorectal cancer (CRC), pancreatic cancer (PC), gastric cancer (GC), and esophageal cancer (EC).

Therapeutic Potential of 6-Gingerol in Prevention of Colon Cancer Induced by Azoxymethane through the Modulation of Antioxidant Potential and Inflammation

A polyphenolic component of ginger, 6-gingerol, is widely reported to possess antioxidant, anti-inflammatory and anticancer activities. In the current study, it was aimed to investigate the anticancer effects of 6-gingerol (6-Gin) on azoxymethane (AOM)-induced colon cancer in rats. The results reveal that 6-Gin treatment significantly improves the antioxidant status disturbed by AOM intoxication. The 6-Gin treatment animal group showed enhanced activity of catalase (CAT) (46.6 ± 6.4 vs. 23.3 ± 4.3 U/mg protein), superoxide dismutase (SOD) (81.3 ± 7.6 vs. 60.4 ± 3.5 U/mg protein) and glutathione-S-transferase (GST) (90.3 ± 9.4 vs. 53.8 ± 10 mU/mg protein) (p < 0.05) as compared to the disease control group. Furthermore, the results reveal that AOM significantly enhances the inflammatory response and 6-gingerol potentially attenuates this response, estimated by markers, such as tumor necrosis factor-α (TNF-α) (1346 ± 67 vs. 1023 ± 58 pg/g), C-reactive protein (CRP) (1.12 ± 0.08 vs. 0.92 ± 0.7 ng/mL) and interleukin-6 (IL-6) (945 ± 67 vs. 653 ± 33 pg/g). In addition, the lipid peroxidation estimated in terms of malondialdehyde (MDA) provoked by AOM exposure is significantly reduced by 6-gingerol treatment (167 ± 7.5 vs. 128.3 nmol/g). Furthermore, 6-gingerol significantly maintains the colon tissue architecture disturbed by the AOM treatment. Loss of tumor suppressor protein, phosphatase and tensin homolog (PTEN) expression was noticed in the AOM treated group, whereas in the animals treated with 6-gingerol, the positivity of PTEN expression was high. In conclusion, the current findings advocate the health-promoting effects of 6-gingerol on colon cancer, which might be due to its antioxidant and anti-inflammatory potential.

Investigation of the expression levels of CDH1, FHIT, PTEN, and TTPAL genes in colorectal tumors

BACKGROUND

The main aim of the study is to assess expression levels of CDH1, FHIT, PTEN, and TTPAL genes in tumors and peripheral bloods of colorectal cancer patients in staged I-IV.

METHODS

Gene expression analysis of related genes were performed for tumor tissues and peripheral blood samples of 51 colorectal cancer patients and colon tissues and blood samples of 5 healthy individuals. The real-time-PCR reaction method was used for the analysis.

RESULTS

Alteration of mRNA levels of related genes in tumor tissues of colorectal cancer cases was determined compared to control tissues. GAPDH and TBP were used for the normalization. While the mRNA levels of CDH1 decreased, the mRNA level of the FHIT and TTPAL genes increased in the tumor tissues. There was no PTEN gene expression difference in tumor tissues (total). The mRNA levels of the CDH1 and PTEN genes were increased while the mRNA levels of FHIT and TTPAL genes decreased in the blood (total). T he mRNA levels of the CDH1 gene decreased at each stage (I-IV) in the tumor tissues and increased at each stage (I-IV) in the blood. T he PTEN gene mRNA levels at each stage were controversial. The mRNA levels of the FHIT gene increased at stage I-II-III, decreased at stage IV in the tissues and decreased at each stage (I-IV) in the blood. The mRNA levels of TTPAL gene increased at each stage (I-IV) in the tissues and decreased at each stage (I-IV) in the blood.

Methylation as a critical epigenetic process during tumor progressions among Iranian population: an overview

Cancer is one of the main health challenges and leading causes of deaths in the world. Various environmental and genetic risk factors are associated with tumorigenesis. Epigenetic deregulations are also important risk factors during tumor progression which are reversible transcriptional alterations without any genomic changes. Various mechanisms are involved in epigenetic regulations such as DNA methylation, chromatin modifications, and noncoding RNAs. Cancer incidence and mortality have a growing trend during last decades among Iranian population which are significantly related to the late diagnosis. Therefore, it is required to prepare efficient molecular diagnostic panels for the early detection of cancer in this population. Promoter hyper methylation is frequently observed as an inhibitory molecular mechanism in various genes associated with DNA repair, cell cycle regulation, and apoptosis during tumor progression. Since aberrant promoter methylations have critical roles in early stages of neoplastic transformations, in present review we have summarized all of the aberrant methylations which have been reported during tumor progression among Iranian cancer patients. Aberrant promoter methylations are targetable and prepare novel therapeutic options for the personalized medicine in cancer patients. This review paves the way to introduce a non-invasive methylation specific panel of diagnostic markers for the early detection of cancer among Iranians.

Hypermethylation of secreted frizzled related protein 2 gene promoter serves as a noninvasive biomarker for HBV-associated hepatocellular carcinoma

For patients with hepatocellular carcinoma (HCC), early detection is critical to improve survival. Secreted frizzled-related protein 2 (SFRP2) is a candidate tumor suppressor as Wnt antagonist and SFRP2 promoter has been found hypermethylated in various malignancies. This study aimed to investigate the methylation status of SFRP2 promoter in hepatitis B virus (HBV) associated HCC and estimate its diagnostic value as a non-invasive biomarker. A total of 293 patients, including 132 patients with HBV-associated HCC, 121 with chronic hepatitis B (CHB) and 40 healthy controls (HCs) were enrolled. SFRP2 methylation level in peripheral mononuclear cells (PBMCs) was quantitatively detected by MethyLight. SFRP2 methylation level was significantly higher in patients with HBV-associated HCC than in those with CHB (p < 0.001) and HCs (p < 0.001) while mRNA level of SFRP2 was significantly lower in HCC group than the other two groups (p < 0.05). In HCC subgroup, SFRP2 methylation level markedly increased in patients >50 years old, female, with negative HBeAg, negative HBV-DNA and poor differentiation compared with the remaining groups (P < 0.05). Furthermore, SFRP2 methylation level showed a significantly better diagnostic value than alpha-fetoprotein (AFP) and the combination of AFP and methylation levels of SFRP2 markedly improved the area under the receiver operating characteristic curve (p < 0.05). In conclusion, hypermethylation of SFRP2 promoter exists in HBV-associated HCC. The combination of SFRP2 methylation level in PBMCs and AFP could significantly improve the diagnostic ability of AFP in discriminating HBV-associated HCC from CHB and SFRP2 methylation level had the potential to serve as a non-invasive biomarker for HCC diagnosis.

Expression and clinical correlation of Survivin and PTEN in gastric cancer patients

Reports on the correlation between the expression of Survivin/phosphatase and tensin homolog (PTEN) proteins and clinical factors in gastric cancer (GC) are varied, and the sample sizes were also not sufficient. The present study aimed to detect the expression of Survivin and PTEN proteins in GC patients on the basis of a greater number of specimens and to analyze the correlation with clinical features and survival. The results revealed that the Survivin expression rates in GC, normal tissues and metastatic lymph nodes were 72% (232/322), 5% (6/120) and 80% (36/45), respectively, while the PTEN expression rates were 34% (109/322), 92.5% (111/120) and 24.4% (11/45), respectively, and the differences between cancer and normal tissue or metastatic lymph nodes were significant for both proteins (P<0.05). The expression of Survivin was significantly associated with gross type, depth of invasion, distant metastasis, tumor, necrosis and metastasis (TNM) stage and vascular invasion, while PTEN expression was predominantly associated with age, tumor size, invasion depth, TNM stage and lymphatic invasion in GC patients (P<0.05). The expression of both was associated with postoperative metastasis and metastatic site (P=0.007 and P=0.011 for Survivin, and P=0.002 and P=0.005 for PTEN). There was a negative association between the expression levels of Survivin and PTEN (P=0.001, r=-0.524). The expression levels of both were also associated with prognosis. The expression of Survivin and PTEN protein exhibit opposing trends in GC, which may indicate adverse biological effects in the occurrence of GC. The Survivin and PTEN expression levels are likely to be an important molecular event in gastric tumorigenesis and may be considered as molecular markers of GC progression and reliable prognostic indicators of GC.

Prevalence of APC and PTEN Alterations in Urachal Cancer

Urachal carcinoma (UrC) is a rare tumor with remarkable histological and molecular similarities to colorectal cancer (CRC). Adenomatous polyposis coli (APC) is the most frequently affected gene in CRC, but the prevalence and significance of its alterations in UrC is poorly understood. In addition, loss of phosphatase and tensin homologue (PTEN) was shown to be associated with therapy resistance in CRC. Our primary aim was to assess specific genetic alterations including APC and PTEN in a large series of UrC samples in order to identify clinically significant genomic alterations. We analyzed a total of 40 UrC cases. Targeted 5-gene (APC, PTEN, DICER1, PRKAR1A, TSHR, WRN) panel sequencing was performed on the Illumina MiSeq platform (n = 34). In addition, ß-catenin (n = 38) and PTEN (n = 30) expressions were assessed by immunohistochemistry. APC and PTEN genes were affected in 15% (5/34) and 6% (2/34) of cases. Two of five APC alterations (p.Y1075*, p.K1199*) were truncating pathogenic mutations. One of the two PTEN variants was a pathogenic frameshift insertion (p.C211fs). In 29% (11/38) of samples, at least some weak nuclear ß-catenin immunostaining was detected and PTEN loss was observed in 20% (6/30) of samples. The low prevalence of APC mutations in UrC represents a characteristic difference to CRC. Based on APC and ß-catenin results, the Wnt pathway seems to be rarely affected in UrC. Considering the formerly described involvement of PTEN protein loss in anti-EGFR therapy-resistance its immunohistochemical testing may have therapeutic relevance.

PTEN: A Thrifty Gene That Causes Disease in Times of Plenty?

The modern obesity epidemic with associated disorders of metabolism and cancer has been attributed to the presence of "thrifty genes". In the distant past, these genes helped the organism to improve energy efficiency and store excess energy safely as fat to survive periods of famine, but in the present day obesogenic environment, have turned detrimental. I propose PTEN as the likely gene as it has functions that span metabolism, cancer and reproduction, all of which are deranged in obesity and insulin resistance. The activity of PTEN can be calibrated in utero by availability of nutrients by the methylation arm of the epigenetic pathway. Deficiency of protein and choline has been shown to upregulate DNA methyltransferases (DNMT), especially 1 and 3a; these can then methylate promoter region of PTEN and suppress its expression. Thus, the gene is tuned like a metabolic rheostat proportional to the availability of specific nutrients, and the resultant "dose" of the protein, which sits astride and negatively regulates the insulin-PI3K/AKT/mTOR pathway, decides energy usage and proliferation. This "fixes" the metabolic capacity of the organism periconceptionally to a specific postnatal level of nutrition, but when faced with a discordant environment, leads to obesity related diseases.

MicroRNAs that regulate PTEN as potential biomarkers in colorectal cancer: a systematic review

PURPOSE

MicroRNAs (miRNAs) participate in a variety of biological processes, including tumorigenesis, progression, invasion, and drug resistance to multiple cancers. Phosphatase and tensin homolog (PTEN) is a cancer suppressor gene that has been certified to be regulated by miRNAs in various tumors, including colorectal cancer (CRC). In this review, we screened articles focusing on low PTEN expression in CRC, observed the expression of related miRNAs, analyzed their correlation and relationship with clinicopathological features, and discussed the possibility of these miRNAs as prognostic molecules.

METHODS

We conducted a systematic search for articles published in the Web of Science, PubMed and EBSCO databases between January 1, 2002, and July 18, 2019. We identified these studies by using combinations of the following index entries and key words: 'colorectal tumor OR colorectal neoplasm OR colorectal carcinoma OR colorectal cancer OR CRC', 'protein tyrosine phosphatase OR PTEN', and 'microRNA OR MiRNA OR miRNA OR MicroRNA'. Moreover, we evaluated the underlying association between alterations in PTEN and CRC prognosis.

RESULTS

PTEN expression was obviously lower in CRC tissues than in normal mucosa. However, PTEN expression did not differ significantly between adenoma and normal tissues. PTEN tends to be negatively associated with tumor size and metastasis. MiR-21, miR-200a, miR-543, miR-32, miR-92a, miR-26a, miR-106a and miR-181a were correlated with the downregulation of PTEN. MiR-26a, miR-106a and miR-181a were obviously higher in CRC tissues than in normal tissues, while PTEN was downregulated in CRC tissues. Additionally, miRNAs were mainly positively correlated with distant metastasis, followed by TNM stage. The relationship between miRNAs and tumor differentiation is controversial. However, there were no significant differences between miRNAs and either sex or age.

CONCLUSIONS

The loss of PTEN may be a diagnostic factor for CRC patients. The above-mentioned miRNAs may function as oncogenes in CRC and represent potential targets for CRC therapy. However, further prospective clinical studies are necessary.

Current Update of Laboratory Molecular Diagnostics Advancement in Management of Colorectal Cancer (CRC)

Colorectal cancer (CRC) continues to be one of the most common cancers globally. The incidence has increased in developing countries in the past few decades, this could be partly attributed to aging populations and unhealthy lifestyles. While the treatment of CRC has seen significant improvement since the advent of target-specific therapies and personalized medicine, CRC is oftentimes detected at late or advanced stages, thereby reducing the efficacy of treatment. Hence, screening for early detection is still the key to combat CRC and to increase overall survival (OS). Considering that the field of medical diagnostics is moving towards molecular diagnostics, CRC can now be effectively screened and diagnosed with high accuracy and sensitivity. Depending on the tumor genotype and genetic profile of the individual, personalized treatments including tyrosine kinase inhibitor therapy and immunotherapy can be administered. Notably, there can be no one single treatment that is effective for all CRC patients due to the variation in tumor genetics, which highlights the importance of molecular diagnostics. This review provides insights on therapeutic modalities, molecular biomarkers, advancement of diagnostic technologies, and current challenges in managing CRC.

PTEN as a Prognostic/Predictive Biomarker in Cancer: An Unfulfilled Promise?

Identifying putative biomarkers of clinical outcomes in cancer is crucial for successful enrichment, and for the selection of patients who are the most likely to benefit from a specific therapeutic approach. Indeed, current research in personalized cancer therapy focuses on the possibility of identifying biomarkers that predict prognosis, sensitivity or resistance to therapies. Phosphatase and tensin homolog deleted on chromosome 10 (PTEN) is a tumor suppressor gene that regulates several crucial cell functions such as proliferation, survival, genomic stability and cell motility through both enzymatic and non-enzymatic activities and phosphatidylinositol 3-kinase (PI3K)-dependent and -independent mechanisms. Despite its undisputed role as a tumor suppressor, assessment of PTEN status in sporadic human tumors has yet to provide clinically robust prognostic, predictive or therapeutic information. This is possibly due to the exceptionally complex regulation of PTEN function, which involves genetic, transcriptional, post-transcriptional and post-translational events. This review shows a brief summary of the regulation and function of PTEN and discusses its controversial aspects as a prognostic/predictive biomarker.

Mechanisms of PTEN loss in cancer: It's all about diversity

PTEN is a phosphatase which metabolises PIP₃, the lipid product of PI 3-Kinase, directly opposing the activation of the oncogenic PI3K/AKT/mTOR signalling network. Accordingly, loss of function of the PTEN tumour suppressor is one of the most common events observed in many types of cancer. Although the mechanisms by which PTEN function is disrupted are diverse, the most frequently observed events are deletion of a single gene copy of PTEN and gene silencing, usually observed in tumours with little or no PTEN protein detectable by immunohistochemistry. Accordingly, with the exceptions of glioblastoma and endometrial cancer, mutations of the PTEN coding sequence are uncommon (<10%) in most types of cancer. Here we review the data relating to PTEN loss in seven common tumour types and discuss mechanisms of PTEN regulation, some of which appear to contribute to reduced PTEN protein levels in cancers.

Long non‑coding RNA Fer‑1‑like family member 4 suppresses hepatocellular carcinoma cell proliferation by regulating PTEN in vitro and in vivo

The aim of the present study was to investigate the potential role of long non‑coding RNA Fer‑1‑like family member 4 (FER1L4) in the proliferation of hepatocellular carcinoma (HCC) through the regulation of phosphatase and tensin homolog (PTEN) expression. Reverse transcription‑quantitative polymerase chain reaction (RT‑qPCR) was used to detect the expression levels of FER1L4 and PTEN mRNA in HCC tissues, and western blotting was performed to measure the protein expression level of PTEN; MTT and colony formation assays were performed to detect the cell proliferative ability. Furthermore, nude mice were injected with transfected HCC cells and the tumor volume and weight were measured. The results indicated that FER1L4 was expressed at a low level in human HCC tissues compared with adjacent normal tissues. Functional studies indicated that FER1L4 may inhibit the proliferative ability of HCC cells. In addition, PTEN was highly expressed in HCC tissues compared with normal adjacent tissues and was positively associated with FER1L4. In addition, it was demonstrated that FER1L4 inhibited the proliferative ability of HCC cells in vitro, and silencing FER1L4 expression by small interfering RNAs promoted the growth of HCC tumors in vivo. Therefore, FER1L4 may be a potent therapeutic target for HCC.

Investigating Effect of Rapamycin and Metformin on Angiogenesis in Hepatocellular Carcinoma Cell Line

Purpose: Human hepatocellular carcinoma is one of the most common causes of death in the world. Metformin and rapamycin may decrease the expression of VEGF protein and subsequently angiogenesis. The purpose of this study was to evaluate the effect of these two drugs on expression of VEGF protein and the cell proliferation in the hepatocellular carcinoma cell line (ATCC HB-8065).

Methods: HepG2 was cultured in RPMI-1640 medium at 37°C for 48h as a pre-culture and then treated by different concentrations of metformin (0, 5, 10 and 20 mM) and rapamycin (0, 5, 10 and 20 nM) at different times (12, 24 and 48 h). Cell viability was assessed by the MTT assay. Total RNA was extracted by the Trizol reagent and VEGF gene expression was analyzed by quantitative real-time PCR and was calculated by 2^–ΔCt method. The VEGF protein level was determined by Elisa assay. Finally, Apoptosis index was calculated by DAPI staining.

Results: Metformin and rapamycin significantly decrease cancer cells viability (p<0.05). Rapamycin but not metformin decreases VEGF gene expression in HepG2 cells. Metformin and rapamycin significantly induce cell apoptosis in hepatocellular carcinoma (HCC) cells.

Conclusion: Metformin and rapamycin have an anti-tumor effect on HCC. According to our data rapamycin might have an anti-angiogenesis effect via inhibition of VEGF expression. Our results provide an insight into future clinical strategies to improve chemotherapy outcomes in HCC.

Assessment of PI3K/AKT/PTEN signaling pathway activity in colorectal cancer using quantum dot-conjugated antibodies

In certain patients with advanced colorectal cancer, loss of phosphatase and tensin homolog deleted on chromosome 10 (PTEN) activity is observed. PTEN is a major gatekeeper gene of the AKT serine/threonine kinase (AKT) signaling pathway responsible for the proliferative activity of cells. The assessment of AKT activity may be a prognostic factor or a predictor of response to the targeted therapies against particular signaling proteins. To precisely identify the cause and the place of the pathway deregulation, it is necessary to identify phosphorylation states and concentrations of several proteins located at different levels of the regulatory cascade. In the present study, we propose the simultaneous use of specific antibodies conjugated with different quantum dots to highlight the nature of AKT/PKB cascade deregulation in patients with colorectal cancer and the loss of PTEN expression in tumor tissue. Fifty patients with colorectal cancer of no specific location were enrolled in the study. The expression of the PTEN protein, and concentrations of phosphorylated/activated forms of 3-Phosphoinositide-dependent kinase 1 (PDK1) and AKT were assessed using quantum dot-conjugated antibodies. In patients with a diminished or complete loss of the PTEN expression in the tumor tissue increased levels of activated/phosphorylated forms of PDK1 (Phospho-PDK1-Ser241) and AKT (Phospho-AKT-Thr308) proteins were found, which are responsible for the permanent activation of the phosphoinositide 3-kinase/AKT/PTEN signaling pathway in certain cases of colorectal cancer.

Long noncoding RNA CCAT1 functions as a ceRNA to antagonize the effect of miR-410 on the down-regulation of ITPKB in human HCT-116 and HCT-8 cells

Colorectal cancer is one of the most common malignancies, which has seriously affected people's health. Abnormal expression of long non-coding RNAs and microRNAs are closely related to the process of occurrence, development, invasion and metastasis of colorectal cancer. However, the effect of lnc CCAT1 on human HCT-116/HCT-8 cells and its potential mechanism were investigated. In present study, differential expression of CCAT1, miR-410 and ITPKB were detected in colon cancer tissues and adjacent parts. Then the prediction programs were applied to predict the target genes of miR-410. The complementary bindings of miR-410 with lnc CCAT1 and ITPKB were assessed by luciferase assays. The interaction between LncRNA CCAT1 and miR-410 was analyzed. In addition, the mRNA and protein of ITPKB and apoptosis factors were examined in cells after miR-410 overexpression or silencing. Meanwhile, MTT and flow cytometer were used to detect the cells proliferation and apoptosis level. Results showed that CCAT1 and miR-410 were up-regulated in colon cancer tissues, but ITPKB was down-regulated. Lnc CCAT1 and ITPKB were predicted to be the targets of miR-410 and the prediction were verified by luciferase assays. The expression of lnc CCAT1 and ITPKB were inhibited by miR-410 in human HCT-116/HCT-8 cells. Meanwhile, lnc CCAT1 could lead to a decrease of miR-410. Furthermore, miR-410 overexpression could promote cell proliferation and reduce apoptosis. In summary, these data demonstrated that miR-410 could promote cell proliferation and reduce apoptosis by inhibiting ITPKB expression and the expression of lnc CCAT1 antagonized the effect of miR-410.

Non-Coding RNAs as Predictive Biomarkers to Current Treatment in Metastatic Colorectal Cancer

The onset and selection of resistant clones during cancer treatment with chemotherapy or targeted therapy is a major issue in the clinical management of metastatic colorectal cancer patients. It is possible that a more personalized treatment selection, using reliable response-to-therapy predictive biomarkers, could lead to an improvement in the success rate of the proposed therapies. Although the process of biomarker selection and validation could be a long one, requiring solid statistics, large cohorts and multicentric validations, non-coding RNAs (ncRNAs) and in particular microRNAs, proved to be extremely promising in this field. Here we summarize some of the main studies correlating specific ncRNAs with sensitivity/resistance to chemotherapy, anti-VEGF therapy, anti-EGFR therapy and immunotherapy in colorectal cancer (CRC).

MicroRNA-194 modulates epithelial-mesenchymal transition in human colorectal cancer metastasis

MicroRNAs (miRNAs), as key regulators of gene expression, are closely related to tumor occurrence and progression. MiR-194 has been proved as a tumor regulatory factor in various cancers; however, the biological function and mechanism of action in colorectal cancer (CRC) have not been well explored. In the present study, we found that miR-194 expression is upregulated in CRC clinical specimens, while overexpression of miR-194 promotes cell migration and invasion in CRC cell lines. Besides, miR-194 significantly influenced the epithelial–mesenchymal transition (EMT) markers by downregulating E-cadherin expression (P<0.01) and upregulating vimentin and MMP-2 expression (P<0.001, P<0.05). Cell migration is the cell movement related to actin cytoskeleton. In this study, we found miR-194 increased cell polarization in SW480 cells. Moreover, zymography assay showed that miR-194 significantly upregulated the gelatin-degrading activity of MMP-2 (P<0.01). Collectively, our findings suggest that miR-194 functions as a tumor promoter in CRC, which may provide new insights for the study of CRC development and metastasis.

Exploration of the regulatory effect of miR-21 on breast cancer cell line proliferation and invasion as well as the downstream target genes

OBJECTIVE

To study the regulatory effects of miR-21 on breast cancer cell line proliferation and invasion as well as the downstream target genes.

METHODS

Breast cancer cell lines MCF-7 were cultured and transfected with miR-21 mimics and the corresponding negative control mimics (NC mimics), and then MTS kits were used to detect cell viability. Transwell experiment was used to detect cell invasion ability, and fluorescence quantitative PCR was used to detect the expression of proliferation and invasion-related genes in cells.

RESULTS

24 h after transfection of miR-21 mimics and NC mimics, cell OD value and the number of invasive cells of miR-21 group were significantly higher than those of NC group, and mRNA contents of PDCD-4, FasL, PTEN, RhoB, Maspin, TIMP3 and RECK in cells were significantly lower than those of NC group.

CONCLUSION

miR-21 can promote the proliferation and invasion of breast cancer cell lines, and its downstream target genes include PDCD-4, FasL, PTEN, RhoB, Maspin, TIMP3 and RECK.