Corrigendum: Pretreatment level of serum sialic acid predicts both qualitative and quantitative bone metastases of prostate cancer.

[This corrects the article DOI: 10.3389/fendo.2024.1338420.].

Pretreatment level of serum sialic acid predicts both qualitative and quantitative bone metastases of prostate cancer.

Background: Recently, serum sialic acid (SA) has emerged as a distinct prognostic marker for prostate cancer (PCa) and bone metastases, warranting differential treatment and prognosis for low-volume (LVD) and high-volume disease (HVD). In clinical settings, evaluating bone metastases can prove advantageous. Objectives: We aimed to establish the correlation between SA and both bone metastasis and HVD in newly diagnosed PCa patients. Methods: We conducted a retrospective analysis of 1202 patients who received a new diagnosis of PCa between November 2014 and February 2021. We compared pretreatment SA levels across multiple groups and investigated the associations between SA levels and the clinical parameters of patients. Additionally, we compared the differences between HVD and LVD. We utilized several statistical methods, including the non-parametric Mann-Whitney U test, Spearman correlation, receiver operating characteristic (ROC) curve analysis, and logistic regression. Results: The results indicate that SA may serve as a predictor of bone metastasis in patients with HVD. ROC curve analysis revealed a cut-off value of 56.15 mg/dL with an area under the curve of 0.767 (95% CI: 0.703-0.832, P < 0.001) for bone metastasis versus without bone metastasis and a cut-off value of 65.80 mg/dL with an area under the curve of 0.766 (95% CI: 0.644-0.888, P = 0.003) for HVD versus LVD. Notably, PCa patients with bone metastases exhibited significantly higher SA levels than those without bone metastases, and HVD patients had higher SA levels than LVD patients. In comparison to the non-metastatic and LVD cohorts, the cohort with HVD exhibited higher levels of alkaline phosphatase (AKP) (median, 122.00 U/L), fibrinogen (FIB) (median, 3.63 g/L), and prostate-specific antigen (PSA) (median, 215.70 ng/mL), as well as higher Gleason scores (> 7). Multivariate logistic regression analysis demonstrated that an SA level of > 56.15 mg/dL was independently associated with the presence of bone metastases in PCa patients (OR = 2.966, P = 0.018), while an SA level of > 65.80 mg/dL was independently associated with HVD (OR = 1.194, P = 0.048). Conclusion: The pretreatment serum SA level is positively correlated with the presence of bone metastases.

Melatonin protects against Epirubicin-induced ovarian damage.

One major side effect of chemotherapy that young women with cancer suffer from is ovarian damage. Therefore, it is necessary to study the pathogenesis of chemotherapeutic drugs in order to develop pharmaceutical agents to preserve fertility. Epirubicin is one of the commonly used chemotherapy drugs for breast cancer patients. This research explored the side effects of epirubicin in mice. We found that epirubicin significantly reduced the body weight, the weight of the ovaries and uteri, and the pups' number, while melatonin, which is extremely resistant to oxidation, significantly reduced these damages. Moreover, co-treatment with melatonin prevented epirubicin-induced decrease in E2 and progesterone, and the loss of follicles. Mechanism study showed that melatonin significantly reduced the levels of proapoptotic genes p53, Caspase3, and Caspase9 while it upregulated antiapoptotic factors Bcl-2 and Bcl2l1, and antioxidant genes superoxide dismutase 1 and catalase compared with the epirubicin group. In addition, melatonin markedly reduced reactive oxygen species (ROS) and the transcription of Caspase12 and Chop, which is vital in endoplasmic reticulum stress (ERS)-mediated apoptosis. These results indicate melatonin protects against epirubicin-induced ovarian damage by reducing ROS-induced ERS. Therefore, melatonin has a therapeutic potential for the protection of ovarian function and preservation of fertility during chemotherapy.

New insights of subfertility among transplanted women: Immunosuppressive drug FK506 leads to calcium leak and oocyte activation before fertilization.

FKBP12, known as FK506 binding protein, binds to immunosuppressive drug FK506, which must be taken by patients who received organ transplant. The side effect of FK506 is that women have difficulties in bearing a baby, so it is important to find the reason of their subfertility. This research explored the expression of FKBP12 in pre-implantation embryos and investigated its potential effect on reproduction. The results demonstrate that FKBP12 had good co-localization with endoplasmic reticulum and inositol-1, 4, 5- trisphosphate receptor in pre-implantation stages. Inhibiting FKBP12 by FK506 significantly increased the rate of 1-cell and fragmented embryos, greatly reduced the rate of 2-cell embryos during in vitro fertilization. When the mice received FK506 by gavage for 21 days, the calcium intensity of oocytes was decreased, these mice were subfertile and gave birth to significantly less pups during 6-month breeding period. QPCR demonstrated that Fbxo43 and P27kip, which are related to the release of MII oocyte arrest, and calcium channel partner protein Orai1 were downregulated, while Cdc2 and Ca2+ sensor at ER, stromal interaction molecule 1 (Stim1) were upregulated for a short time after adding FK506. Further exploration discovered that FK506 treatment increased Ca2+ concentration in the cytoplasm and caused pronucleus formation, however, the rate of parthenogenetic activation was lower compared to SrCl2 group. These findings identify the previously unknown role of FKBP12 in female reproduction which contributes to the release of calcium via IP3 R channel and might open up new strategies for women who want to bear a baby after transplantation.

The function of high-density lipoprotein and low-density lipoprotein in the maintenance of mouse ovarian steroid balance.

The membrane proteins, low-density lipoprotein receptor (LDLR) and scavenger receptor class B member 1 (SR-BI, gene name Scarb1), are lipoprotein receptors that play central roles in lipoprotein metabolism. Cholesterol bound in high-density lipoprotein (HDL) and LDL is transported into cells mainly by SR-BI and LDLR. The relative contribution of LDL and HDL to the steroidogenic cholesterol pool varies among species and may vary among tissues within one species. To investigate which of these pathways is more important in the supply of cholesterol in mouse ovary, we utilized immunohistochemistry, western blotting, RNAi, and RT-PCR as well as Ldlr-/- mice to explore the uptake of HDL and LDL in the ovary. Our data demonstrate that both SR-BI and LDLR are present in the interstitial cells, thecal cells, and corpora lutea (CLs), and their expression fluctuates with the development of follicles and CLs. The intracellular cholesterol concentration was significantly decreased when Ldlr or Scarb1 was silenced in luteal cells. Furthermore, Ldlr-/- mice had lower progesterone and estrogen levels compared to wild-type mice, and when Ldlr-/- mice were treated with the inhibitor of de novo cholesterol synthesis, lovastatin, serum progesterone, and estrogen concentrations were further reduced. These results demonstrate that both LDLR and SR-BI play important roles in importing cholesterol and that both HDL and LDL are crucial in steroidogenesis in mouse ovaries.