Overexpression of Hiwi Inhibits the Cell Growth of Chronic Myeloid Leukemia K562 Cells and Enhances Their Chemosensitivity to Daunomycin

Mechanisms Behind the Impact of PIWI Proteins on Cancer Cells: Literature Review

The P-Element-induced wimpy testis (PIWI) group of proteins plays a key role in RNA interference, particularly in the regulation of small non-coding RNAs. However, in recent years, PIWIs have gained attention in several diseases, mainly cancer. Therefore, the aim of this review was to evaluate current knowledge about the impact of PIWI proteins on cancer cells. PIWIs alter a number of pathways within cells, resulting in significant changes in cell behavior. Basic processes of cancer cells have been shown to be altered by either overexpression or inhibition of PIWIs. Regulation of apoptosis, metastasis, invasion, or proliferation of cancerous cells by these proteins proves their involvement in the progression of the malignancy. It has been revealed that PIWIs are also connected with cancer stem cells (CSCs), which proves their ability to become a therapeutic target. However, research on this topic is still fairly limited, and with significant differences between cancer types, it is necessary to refrain from making any decisive conclusions.

PIWI pathway: bridging acute myeloid leukemia stemness and cellular differentiation

PIWI proteins are stem cell-associated RNA-binding proteins crucial for survival of germ stem cells. In cancer, PIWI proteins are overexpressed. Specifically, PIWIL4 is highly expressed in multiple cancers with the highest levels found in acute myeloid leukemia (AML), an aggressive malignancy propagated by a population of leukemia stem cells (LSCs). Bamezai et al. (Blood Journal, blood, 2023, 142, 90-105) demonstrated that PIWIL4 supports AML blasts and LSCs but is not necessary for healthy human hematopoietic progenitor stem cells (HSPCs) function in vivo. PIWIL4 in AML acts by preventing the accumulation of R-loops in key genes for LSCs persistence implicated in: DNA damage, replicative stress, and transcription arrest. We report that PIWIL4 expression significantly decreases in THP-1 monocytes exposed to a differentiating agent, suggesting a potential role for PIWIL4 in maintaining the undifferentiated state of myeloid cells. PIWIL4 overexpression could lead to the emergence of LSCs, driving leukemia propagation and maintenance. Our findings correlate with the persistent overexpression of PIWIL4 in myeloid cancers as reported by Bamezai et al., and suggest that PIWIL4 may be involved in myeloid cell differentiation. In this perspective, we highlight recent findings on the implication of PIWI pathway in maintaining AML stemness. Additionally, we propose further investigation on the role of PIWI pathway in oncogenesis and cellular differentiation as a strategy to identify biomarkers and therapeutic targets for AML.

PIWIL1 gene polymorphism and pediatric acute lymphoblastic leukemia relapse susceptibility among Chinese children: a five-center case-control study

Objective

PIWIL1 polymorphisms' role in pediatric acute lymphoblastic leukemia (ALL) relapse susceptibility remains undiscovered.

Methods

A case-control designed and multiple logistic regression model was performed to evaluate the overall risk of pediatric ALL and five single-nucleotide polymorphisms (SNPs) of PIWIL1 gene (rs35997018 C>T, rs1106042 A>G, rs7957349 C>G, rs10773771 C>T, and rs10848087 A>G) in 785 cases and 1,323 controls, which were genotyped by TaqMan assay. The odds ratio (OR) and its 95% confidence interval (CI) were used to estimate the relationship. Stratified analysis was used to investigate the correlation of rs1106042 and rs10773771 genotypes and pediatric ALL relapse susceptibility in terms of age, sex, number of white blood cells (WBC), immunophenotyping, gene fusion type, karyotype, primitive/naïve lymphocytes, and minimal residual disease (MRD) in bone marrow. Finally, the haplotype analysis was performed to appraise the relationship between inferred haplotypes of PIWIL1 and pediatric ALL risk.

Results

Among the five analyzed SNPs, rs1106042 A>G was related to increased ALL risk, and rs10773771 C>T was related to decreased ALL risk. Compared to the GG genotype, the rs1106042 GA/AA had a deleterious effect on children of age <120 months, who were female and male, had high or average number of WBC, pro-B ALL, pre-B ALL, T-ALL, low- and middle-risk ALL, E2A-PBX fusion gene, non-gene fusion, abnormal diploid, high hyperdiploid, hypodiploid, and normal diploid. Moreover, rs1106042 A>G harmfully affected primitive/naïve lymphocytes and MRD on days 15-19, day 33, and week 12. On the contrary, rs10773771 TC/CC exhibited a protective effect on ALL children with the TEL-AML fusion gene. Haplotype analysis demonstrated that haplotypes CAGT, TACC, TACT, and TAGT were significantly associated with increased pediatric ALL relapse susceptibility.

Conclusion

PIWIL1 rs1106042 A>G was related to increased ALL risk, and rs10773771 C>T was linked to decreased ALL risk in eastern Chinese children. Rs1106042 GA/AA may predict poor prognosis.

Neurospora crassa is a potential source of anti-cancer agents against breast cancer

Fungi are an excellent source of pharmaceuticals including anti-tumor agents. Neurospora crassa generates metabolites with diverse structural classes, however, its potential as an anti-tumor agent source has not been explored. The purpose of this study aimed to investigate the potential of Neurospora crassa mixture against breast cancer. The in vitro T-47D and MDA-MB-231 experiments showed that N. crassa mixture at the concentrations of both 1.7 and 0.85 µg/ml significantly inhibited tumor cell proliferation, migration and invasion, and 3D spheroid formation. However, the inhibition rates of MCF-10A ranged 10-20% at concentrations of 0.85 and 1.7 µg/ml. The mixture at the concentration of 0.85 µg/ml could significantly downregulate the expressions of transcription factors of E2F1 and E2F3, cancer stem cell-related genes of LIN28, HIWI, and CD133, and onco-lncRNA HOTAIR, and increase CASP3 activity in either T-47D or MDA-MD-231 breast cancer cell lines. In vivo breast cancer C3H mouse model results showed that N. crassa mixture significantly inhibited tumor growth. These findings suggest that N. crassa contains an antitumor component(s) against breast cancer invasiveness, which may inhibit the self-renewal and differentiation of breast cancer stem cells possibly by downregulating cancer stem cell-associated and/or transcription factor genes and oncogenes, and promoting apoptosis.

Transposable elements and Piwi‑interacting RNAs in hemato‑oncology with a focus on myelodysplastic syndrome (Review)

Our current understanding of hematopoietic stem cell differentiation and the abnormalities that lead to leukemogenesis originates from the accumulation of knowledge regarding protein‑coding genes. However, the possible impact of transposable element (TE) mobilization and the expression of P‑element‑induced WImpy testis‑interacting RNAs (piRNAs) on leukemogenesis has been beyond the scope of scientific interest to date. The expression profiles of these molecules and their importance for human health have only been characterized recently due to the rapid progress of high‑throughput sequencing technology development. In the present review, current knowledge on the expression profile and function of TEs and piRNAs was summarized, with specific focus on their reported involvement in leukemogenesis and pathogenesis of myelodysplastic syndrome.

Tiliroside as a CAXII inhibitor suppresses liver cancer development and modulates E2Fs/Caspase-3 axis

Liver cancer is the fatal cause of cancer deaths worldwide due to its aggressiveness and lack of effective therapies. Tiliroside (C₃₀H₂₆O₁₃) is an active compound extracted from herb plant Tribulus terrestris L., which has been used as alternative therapy in clinic practice. However, its therapeutic use against liver cancer has not been previously reported. Here, we showed that Tiliroside exerted significantly higher anti-proliferation effect on liver cancer cell lines Hep3B and SNU-449 than on liver normal cell THLE-3 cells or NC group, respectively, by using MTS assay. Results from colony formation, immigration and invasion assays support the anticancer efficacy of Tiliroside and its low-toxic property while treating liver normal cell THLE-3. 3D spheroid formation and CD133 expression level also displays its anti-stemness effect. It has been showed that Tiliroside may function as Carbonic anhydrases XII (CAXII) inhibitor and affects apoptotic E2F1/E2F3/Caspase-3 axis by using CAXII esterase activity assay, Human carbonic anhydrase 12 (CA-12) ELISA Kit, quantitative reverse transcription PCR (RT-qPCR) as well as CaspACE Assay System, respectively. In summary, we demonstrate for the first time that Tiliroside suppresses liver cancer development possibly by acting as a novel CAXII inhibitor, which warrant further investigation on its therapeutic implications.

MEIS1 promotes expression of stem cell markers in esophageal squamous cell carcinoma

BACKGROUND

MEIS1 (Myeloid ecotropic viral integration site 1) as a homeobox (HOX) transcription factor plays regulatory roles in a variety of cellular processes including development, differentiation, survival, apoptosis and hematopoiesis, as well as stem cell regulation. Few studies have established pluripotency and self-renewal regulatory roles for MEIS1 in human esophageal squamous cell carcinoma (ESCC), and our aim in this study was to evaluate the functional correlation between MEIS1 and the stemness markers in ESCC patients and cell line KYSE-30.

METHODS

Expression pattern of MEIS1 and SALL4 gene expression was analyzed in different pathological features of ESCC patients. shRNA in retroviral vector was used for constantly silencing of MEIS1 mRNA in ESCC line (KYSE-30). Knockdown of MEIS1 gene and the expression pattern of selected stemness markers including SALL4, OCT4, BMI-1, HIWI, NANOG, PLK1, and KLF4 were evaluated using real-time PCR.

RESULTS

Significant correlations were observed between MEIS1 and stemness marker SALL4 in different early pathological features of ESCC including non-invaded tumors, and the tumors with primary stages of progression. Retroviral knockdown of MEIS1 in KYSE-30 cells caused a noteworthy underexpression of both MEIS1 and major involved markers in stemness state of the cells including SALL4, OCT4, BMI-1, HIWI and KLF4.

CONCLUSIONS

The results highlight the important potential role of MEIS1 in modulating stemness properties of ESCCs and cells KYSE-30. These findings may confirm the linkage between MEIS1 and self-renewal capacity in ESCC and support probable oncogenic role for MEIS1 in the disease.

The Prognosis Value of PIWIL1 and PIWIL2 Expression in Pancreatic Cancer

Pancreatic cancer is a highly aggressive manifestation of cancer, and currently presents poor clinical outcome due to its late diagnosis with metastasic disease. Surgery is the only approach with a curative intend; however, the survival rates seen in this type of patient are still low. After surgery, there is a lack of predictive prognosis biomarkers to predict treatment response and survival to establish a personalized medicine. Human P-element-induced wimpy testis 1 (PIWIL1) and P-element-induced wimpy testis 2 (PIWIL2) proteins act as protectors of germline, and their aberrant expression has been described in several types of tumors. In this study, we aimed to assess an association between PIWIL1 and PIWIL2 expression and the prognosis of biliopancreatic cancer patients. For this, we analyzed protein expression in complete resected tumor samples, and found a significant association between PIWIL2 expression and both progression-free and overall survival (p = 0.036 and p = 0.012, respectively). However, PIWIL2 expression was significantly associated with progression-free survival (p = 0.029), and overall survival (p = 0.025) of such tumors originated in the pancreas, but not in the bile duct or ampulla of Vater. Further analysis revealed that PIWIL1 and PIWIL2, at both mRNA and protein expression levels, correlated positively with factors associated to the progenitor molecular subtype of pancreatic cancer. Based on these findings, PIWIL1 and PIWIL2 expression may be considered a potential prognostic biomarker for resectable pancreatic cancer and may serve to guide subsequent adjuvant treatment decisions.

Prevalence and Risk Factors for Osteoporosis in Individuals With COPD: A Systematic Review and Meta-analysis

BACKGROUND

Osteoporosis is prevalent in individuals with COPD. Updated evidence is required to complement the previous systematic review on this topic to provide best practice. The aim of this systematic review and meta-analysis was to quantitatively synthesize data from studies with respect to the prevalence and risk factors for osteoporosis among individuals with COPD.

METHODS

EMBASE, CINAHL, MEDLINE, and PubMed databases were searched for articles containing the key words "COPD," "osteoporosis," "prevalence," and "risk factor." Eligibility screening, data extraction, and quality assessment of the retrieved articles were conducted independently by two reviewers. Meta-analyses were performed to determine osteoporosis prevalence and risk factors in individuals with COPD. Meta-regression analyses were conducted to explore the sources of heterogeneity.

RESULTS

The pooled global prevalence from 58 studies was 38% (95% CI, 34-43). The presence of COPD increased the likelihood of having osteoporosis (OR, 2.83). Other significant risk factors for osteoporosis in COPD patients were BMI < 18.5 kg/m² (OR, 4.26) and the presence of sarcopenia (OR, 3.65).

CONCLUSIONS

Osteoporosis is prevalent in individuals with COPD, and the prevalence seems to be high and similar in many countries. Patients with COPD should be screened for osteoporosis and contributing risk factors.