Preventing Ovarian Cancer

Visualize intracellular β-galactosidase using an asymmetric near-infrared fluorescent probe with a large Stokes shift

β-galactosidase (β-Gal) is an important biomarker of cell senescence and primary ovarian cancer. Therefore, it is of great significance to construct a near-infrared fluorescent probe with deep tissue penetration and a high signal-to-noise ratio for visualization of β-galactosidase in biological systems. However, most near-infrared probes tend to have small Stokes shifts and low signal-to-noise ratios due to crosstalk between excitation and emission spectra. Using d-galactose residues as specific recognition units and near-infrared dye TJ730 as fluorophores, a near-infrared fluorescence probe SN-CR with asymmetric structure was developed for the detection of β-Gal. The probe has a fast reaction equilibrium time (<12 min) with β-Gal, excellent biocompatibility, near-infrared emission (738 nm), low detection limit (0.0029 U/mL), and no crosstalk between the excitation spectrum and emission spectrum (Stokes shifts 142 nm) of the probe. Cell imaging studies have shown that SN-CR can visually trace β-Gal in different cells and distinguish ovarian cancer cells from other cells.

Hysterectomy with opportunistic salpingectomy versus hysterectomy alone

BACKGROUND

Ovarian cancer has the highest mortality rate of all gynaecological malignancies with an overall five-year survival rate of 30% to 40%. In the past two decades it has become apparent and more commonly accepted that a majority of ovarian cancers originate in the fallopian tube epithelium and not from the ovary itself. This paradigm shift introduced new possibilities for ovarian cancer prevention. Salpingectomy during a hysterectomy for benign gynaecological indications (also known as opportunistic salpingectomy) might reduce the overall incidence of ovarian cancer. Aside from efficacy, safety is of utmost importance, especially due to the preventive nature of opportunistic salpingectomy. Most important are safety in the form of surgical adverse events and postoperative hormonal status. Therefore, we compared the benefits and risks of hysterectomy with opportunistic salpingectomy to hysterectomy without opportunistic salpingectomy.

OBJECTIVES

To assess the effect and safety of hysterectomy with opportunistic salpingectomy versus hysterectomy without salpingectomy for ovarian cancer prevention in women undergoing hysterectomy for benign gynaecological indications; outcomes of interest include the incidence of epithelial ovarian cancer, surgery-related adverse events and postoperative ovarian reserve.

SEARCH METHODS

The Cochrane Gynaecology and Fertility (CGF) Group trials register, CENTRAL, MEDLINE, Embase, PsycINFO, CINAHL and two clinical trial registers were searched in January 2019 together with reference checking and contact with study authors.

SELECTION CRITERIA

We intended to include both randomised controlled trials (RCTs) and non-RCTs that compared ovarian cancer incidence after hysterectomy with opportunistic salpingectomy to hysterectomy without opportunistic salpingectomy in women undergoing hysterectomy for benign gynaecological indications. For assessment of surgical and hormonal safety, we included RCTs that compared hysterectomy with opportunistic salpingectomy to hysterectomy without opportunistic salpingectomy in women undergoing hysterectomy for benign gynaecological indications.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures recommended by Cochrane. The primary review outcomes were ovarian cancer incidence, intraoperative and short-term postoperative complication rate and postoperative hormonal status. Secondary outcomes were total surgical time, estimated blood loss, conversion rate to open surgery (applicable only to laparoscopic and vaginal approaches), duration of hospital admission, menopause-related symptoms and quality of life.

MAIN RESULTS

We included seven RCTs (350 women analysed). The evidence was of very low to low quality: the main limitations being a low number of included women and surgery-related adverse events, substantial loss to follow-up and a large variety in outcome measures and timing of measurements.No studies reported ovarian cancer incidence after hysterectomy with opportunistic salpingectomy compared to hysterectomy without opportunistic salpingectomy in women undergoing hysterectomy for benign gynaecological indications. For surgery-related adverse events, there were insufficient data to assess whether there was any difference in both intraoperative (odds ratio (OR) 0.66, 95% confidence interval (CI) 0.11 to 3.94; 5 studies, 286 participants; very low-quality evidence) and short-term postoperative (OR 0.13, 95% CI 0.01 to 2.14; 3 studies, 152 participants; very low-quality evidence) complication rates between hysterectomy with opportunistic salpingectomy and hysterectomy without opportunistic salpingectomy because the number of surgery-related adverse events was very low. For postoperative hormonal status, the results were compatible with no difference, or with a reduction in anti-Müllerian hormone (AMH) that would not be clinically relevant (mean difference (MD) -0.94, 95% CI -1.89 to 0.01; I² = 0%; 5 studies, 283 participants; low-quality evidence). A reduction in AMH would be unfavourable, but due to wide CIs, the postoperative change in AMH can still vary from a substantial decrease to even a slight increase.

AUTHORS' CONCLUSIONS

There were no eligible studies reporting on one of our primary outcomes - the incidence of ovarian cancer specifically after hysterectomy with or without opportunistic salpingectomy. However, outside the scope of this review there is a growing body of evidence for the effectiveness of opportunistic salpingectomy itself during other interventions or as a sterilisation technique, strongly suggesting a protective effect. In our meta-analyses, we found insufficient data to assess whether there was any difference in surgical adverse events, with a very low number of events in women undergoing hysterectomy with and without opportunistic salpingectomy. For postoperative hormonal status we found no evidence of a difference between the groups. The maximum difference in time to menopause, calculated from the lower limit of the 95% CI and the natural average AMH decline, would be approximately 20 months, which we consider to be not clinically relevant. However, the results should be interpreted with caution and even more so in very young women for whom a difference in postoperative hormonal status is potentially more clinically relevant. Therefore, there is a need for research on the long-term effects of opportunistic salpingectomy during hysterectomy, particularly in younger women, as results are currently limited to six months postoperatively. This limit is especially important as AMH, the most frequently used marker for ovarian reserve, recovers over the course of several months following an initial sharp decline after surgery. In light of the available evidence, addition of opportunistic salpingectomy should be discussed with each woman undergoing a hysterectomy for benign indication, with provision of a clear overview of benefits and risks.

Long non-coding RNA SNHG6 promotes cell proliferation and migration through sponging miR-4465 in ovarian clear cell carcinoma

Dysregulation of small nucleolar RNA host gene 6 (SNHG6) exerts critical oncogenic effects and facilitates tumourigenesis in human cancers. However, little information about the expression pattern of SNHG6 in ovarian clear cell carcinoma (OCCC) is available, and the contributions of this long non‐coding RNA to the tumourigenesis and progression of OCCC are unclear. In the present study, we showed via quantitative real‐time PCR that SNHG6 expression was abnormally up‐regulated in OCCC tissues relative to that in unpaired normal ovarian tissues. High SNHG6 expression was correlated with vascular invasion, distant metastasis and poor survival. Further functional experiments demonstrated that knockdown of SNHG6 in OCCC cells inhibited cell proliferation, migration and invasion in vitro as well as tumour growth in vivo. Moreover, SNHG6 functioned as a competing endogenous RNA (ceRNA), effectively acting as a sponge for miR‐4465 and thereby modulating the expression of enhancer of zeste homolog 2 (EZH2). Taken together, our data suggest that SNHG6 is a novel molecule involved in OCCC progression and that targeting the ceRNA network involving SNHG6 may be a treatment strategy in OCCC.

Pim1 promotes cell proliferation and regulates glycolysis via interaction with MYC in ovarian cancer

Background

Ovarian cancer (OC) is the leading cause of death among women with gynecologic malignancies. Recent studies have highlighted the role of Pim1, which belongs to a group of constitutively activated serine/threonine kinases, in cancer development. However, the effect of Pim1 in OC is largely unclear.

Methods

OC cell lines with Pim1 overexpression or knockdown were constructed with len-tivirus transduction. Cell Counting Kit-8, colony formation, glycolysis stress test and in vivo mice models were carried out to assess the effect of Pim1 on OC biological functions. Co-immunoprecipitation assay coupled with western blot were performed to explore the intrinsic mechanisms of Pim1 in OC. Bioinformatic analysis was then performed to evaluate the expression and prognostic value of Pim1.

Results

We present the first evidence that silencing or overexpressing Pim1 can suppress or promote, respectively, OC cell proliferation. Furthermore, we demonstrated that Pim1 can significantly enhance glycolysis in OC cells. In vivo experiments further confirmed that knockdown of Pim1 inhibits the growth of tumors derived from the SKOV3 cell line. To search for the underlying molecular mechanism, we examined the effect of Pim1 on MYC, a pivotal gene in glycolysis, and observed that Pim1-mediated phosphorylation of c-Myc activated the expression of glycolysis-associated key genes such as PGK1 and LDHA. Moreover, we found that the Pim1 inhibitor SMI4a induced chemosensitization to cisplatin. Clinically, Pim1 was also overexpressed in OC and correlated with poor overall survival by bioinformatics analysis.

Conclusion

Together, these results suggest that Pim1 contributes to proliferation and gly-colysis in OC via interaction with MYC and may serve as a potential target in the treatment of OC patients.

Long noncoding RNA NEAT1, regulated by LIN28B, promotes cell proliferation and migration through sponging miR-506 in high-grade serous ovarian cancer

The aberrant expression of long noncoding RNAs (lncRNAs) has been reported frequently in specific cancers, including high-grade serous ovarian cancer (HGSOC). The purpose of the present study was to explore the clinical significance and underlying mechanisms of a significantly dysregulated lncRNA (NEAT1) in HGSOC. Our results showed that elevated NEAT1 expression in human HGSOC specimens correlated with a poor prognosis. Functional experiments demonstrated that knockdown of NEAT1 significantly prohibited ovarian cancer cell proliferation and invasion in vitro and restrained tumor growth in vivo. LIN28B was identified by bioinformatics analysis along with experimental evidence as a direct actor that enhanced NEAT1 stability. A rescue functional assay confirmed that the LIN28B/NEAT1 axis contributed to oncogenic functions in ovarian cancer cells. Moreover, gene expression profile data and dual luciferase reporter assay results demonstrated that NEAT1 functioned as a competing endogenous RNA (ceRNA) for miR-506 to promote cell proliferation and migration. Taken together, our results showed that NEAT1, stabilized by LIN28B, promoted HGSOC progression by sponging miR-506. Thus, NEAT1 can be regarded as a vital diagnostic biomarker for HGSOC and a therapeutic target.