Toxoplasma gondii causes changes in the host's expression of cancer‑associated miRNAs

miRNA, New Perspective to World of Intestinal Protozoa and Toxoplasma

BACKGROUND

miRNAs are known as non-coding RNAs that can regulate gene expression. They are reported in many microorganisms and their host cells. Parasite infection can change or shift host miRNAs expression, which can aim at both parasite eradication and infection.

PURPOSE

This study dealt with examination of miRNA expressed in intestinal protozoan, coccidia , as well as profile changes in host cell miRNA after parasitic infection and their role in protozoan clearance/ survival.

METHODS

The authors searched ISI Web of Sciences, Pubmed, Scholar, Scopus, another databases and articles published up to 2024 were included. The keywords of miRNA, intestinal protozoa, toxoplasma and some words associated with topics were used in this search.

RESULTS

Transfection of miRNA mimics or inhibitors can control parasitic diseases, and be introduced as a new therapeutic option in parasitology.

CONCLUSION

This review can be used to provide up-to date knowledge for future research on these issues.

Deregulation of MicroRNA-146a and 155 expression levels might underlie complicated pregnancy in Toxoplasma Gondii seronegative women

BACKGROUND

To evaluate the ability of the estimated plasma expression levels of genes of microRNA (MiR-) 146a and 155 to differentiate between samples of pregnant women suspected to be infected by T. gondii. 50 newly pregnant women who had at least one of the criteria of high risk for toxoplasma infection and 50 newly primigravida women free of these criteria gave blood samples for qualitative determination of serum toxoplasma antibodies and estimation of plasma expression levels of MiR-146a and 155 using the qRT-PCR. During the pregnancy course, the incidence of pregnancy complications was recorded.

RESULTS

Twenty-six women were IgM-/IgG-, 17 women were IgM+/IgG- and 7 women were IgM+/IgG+. Thirty-two women had pregnancy complications with significantly lower incidence in IgM-/IgG- women. Plasma expression levels of MiR-146a and 155 were significantly higher in total patients compared to control levels and were significantly higher in samples of IgM+/IgG+ patients than in other samples. Statistical analyses defined a high plasma level of MiR-155 as the highly significant predictor for oncoming pregnancy complications and high levels of both microRNAs as predictors for the presence of toxoplasmosis despite seronegativity. Kaplan-Meier regression analysis defined increasing cumulative risk of having toxoplasmosis despite seronegativity with plasma levels of MiR-146a and MiR-155 of 1.2 and 3, respectively.

CONCLUSION

The incidence of pregnancy complications is high, irrespective of the seronegativity of women at high risk of toxoplasmosis. Estimated plasma levels of MiR-155 might identify women liable to develop complications and differentiate seronegative women vulnerable to having T. gondii infection.

TRIAL REGISTRATION

The study protocol was approved preliminarily by the Local Ethical Committee at Benha Faculty of Medicine. Before enrollment, the study protocol was discussed in detail with the study participants, and those accepted to participate in the study signed written fully informed consents. The final approval of the study protocol was obtained after the end of case collection and registered by RC: 5-11-2022.

A novel enemy of cancer: recent investigations into protozoan anti-tumor properties

Cancer remains a significant global health issue, despite advances in screening and treatment. While existing tumor treatment protocols such as surgery, chemotherapy, radiotherapy, targeted therapy, and immunotherapy have proven effective in enhancing the prognosis for some patients, these treatments do not benefit all patients. Consequently, certain types of cancer continue to exhibit a relatively low 5-year survival rate. Therefore, the pursuit of novel tumor intervention strategies may help improve the current effectiveness of tumor treatment. Over the past few decades, numerous species of protozoa and their components have exhibited anti-tumor potential via immune and non-immune mechanisms. This discovery introduces a new research direction for the development of new and effective cancer treatments. Through in vitro experiments and studies involving tumor-bearing mice, the anti-tumor ability of Toxoplasma gondii, Plasmodium, Trypanosoma cruzi, and other protozoa have unveiled diverse mechanisms by which protozoa combat cancer, demonstrating encouraging prospects for their application. In this review, we summarize the anti-tumor ability and anti-tumor mechanisms of various protozoa and explore the potential for their clinical development and application.

Seroprevalence of Toxoplasma gondii infection in women with a gynecological tumor living in eastern China

The association between Toxoplasma gondii (T. gondii) infection and malignancy has attracted increased attention in recent years, but little is known of T. gondii infection among women diagnosed with a gynecological tumor (GT) in China. We conducted a case-control study involving 460 women diagnosed with a GT and 460 age-matched healthy controls (HCs) to estimate the infection process of T. gondii and understand the risk factors of T. gondii infection in patients with a GT. Levels of anti-T. gondii IgG and IgM were measured by enzyme-linked immunoassays every 12 months. After a median follow-up time of 4.3 years (range 4 to 5 years), 55/460 (11.96%) patients with a GT and 15/460 (3.26%) HCs were seroprevalence for T. gondii antibodies, respectively (P = 0.001). IgG antibodies against T. gondii were found in 54 GT patients (11.74%) and 15 HCs (3.26%), respectively (P = 0.001). The seroprevalence of T. gondii IgM antibodies was similar in patients with a GT and with HCs (2.83% vs 1.3%, P = 0.105). Multivariate stepwise logistic regression analysis revealed contact with cats (OR, 6.67; 95% CI [2.89-10.75]; P = 0.001), exposure to soil (OR, 2.16; 95% CI [1.14-4.10]; P = 0.019), being a farm-worker (OR, 4.17; 95% CI [1.20-11.49]; P = 0.006) and history of chemotherapy (OR, 3.16; 95% CI [1.56-6.45]; P = 0.001) to be independent risk factors for T. gondii infection. Women with an ovarian cancer or endometrial cancer had higher T. gondii seroprevalence than that of HCs. Moreover, T. gondii infection in patients with a GT mostly acquired within two years of diagnosis, but the infection in healthy controls had no obvious time characteristics. Here, we demonstrated that T. gondii infection is significantly higher in patients with a GT (especially in women with an ovarian tumor) compared to HCs. Thus, infection with this parasite should be avoided in patients with a GT, and the causal relationship between T. gondii and GTs should be studied in detail.