Engrailed-2 (EN2) - a novel biomarker in epithelial ovarian cancer

Background

Epithelial ovarian cancer is a common malignancy, with no clinically approved diagnostic biomarker. Engrailed-2 (EN2) is a homeodomain-containing transcription factor, essential during embryological neural development, which is dysregulated in several cancer types. We evaluated the expression of EN2 in Epithelial ovarian cancer, and reviewed its role as a biomarker.

Methods

We evaluated 8 Epithelial ovarian cancer cell lines, along with > 100 surgical specimens from the Royal Surrey County Hospital (2009–2014). In total, 108 tumours and 5 normal tissue specimens were collected. En2 mRNA was evaluated by semi-quantitative RT-PCR. Histological sub-type, and platinum-sensitive/−resistant status were compared. Protein expression was assessed in cell lines (immunofluorescence), and in > 150 tumours (immunohistochemistry).

Results

En2 mRNA expression was elevated in serous ovarian tumours compared with normal ovary (p < 0.001), particularly in high-grade serous ovarian cancer (p < 0.0001) and in platinum-resistant tumours (p = 0.0232). Median Overall Survival and Progression-free Survival were reduced with high En2 expression (OS = 28 vs 42 months, p = 0.0329; PFS = 8 vs 27 months; p = 0.0004). Positive cytoplasmic EN2 staining was demonstrated in 78% of Epithelial ovarian cancers, with absence in normal ovary. EN2 positive high-grade serous ovarian cancer patients had a shorter PFS (10 vs 17.5 months; p = 0.0103).

Conclusion

The EN2 transcription factor is a novel ovarian cancer biomarker. It demonstrates prognostic value, correlating with worse Overall Survival and Progression-free Survival. It is hoped that further work will validate its use as a biomarker, and provide insight into the role of EN2 in the development, progression and spread of ovarian cancer.

Advances in the treatment of ovarian cancer: a potential role of antiinflammatory phytochemicals

Epithelial ovarian cancer (EOC) is the leading cause of death among gynecological malignancies worldwide. The five-year survival rates for stage IIIC and IV patients are 29% and 13%, respectively. Type-2 EOC cells have been found to be associated with this late stage disease. In contrast, women diagnosed in stage 1 disease, which mostly exhibits type-1 cells, have a high 5-year survival rate (90%). Recent progress in understanding the pathogenesis of EOC and inflammatory signaling pathways revealed that type-2 cells frequently express a deleted or mutated TP53 (60-80%), or aberrations in BRCA1 (30-60%) and BRCA2 (15-30%). The deletion or mutation of TP53 results in a dysregulated inflammatory signal network and contributes to an immunosuppressive microenvironment. Thus, to be effective, EOC therapy may be necessary to cover two areas: (1) direct cytotoxic killing of cancer cells; (2) reversion of the immunosuppressive microenvironment. Presently the first strategy is advancing rapidly while the second strategy remains behind. Isolation and characterization of cancer stem cells (CSCs) have helped to confirm the dynamic role of the tumor microenvironment in promoting cancer metastasis and recurrence. Based on widely published in vitro and mouse-model data, some anti-inflammatory phytochemicals appear to exhibit activity in modulating the tumor microenvironment. Specifically, apiegenin, baicalein, curcumin, EGCG, genistein, luteolin, oridonin, quercetin, and wogonin repress NF-kappaB (NF-κB, a proinflammatory transcription factor) and inhibit proinflammatory cytokines such as TNF-α and IL-6. Additionally, most of these phytochemicals have been shown to stabilize p53 protein, sensitize TRAIL (TNF receptor apoptosis-inducing ligand) induced apoptosis, and prevent or delay chemotherapy-resistance. Recent studies further indicate that apigenin, genistein, kaempferol, luteolin, and quercetin potently inhibit VEGF production and suppress ovarian cancer cell metastasis in vitro. Lastly, oridonin and wogonin were suggested to suppress ovarian CSCs as is reflected by down-regulation of the surface marker EpCAM. Unlike NSAIDS (non-steroid anti-inflammatory drugs), well documented clinical data for phyto-active compounds are lacking. In order to evaluate objectively the potential benefit of these compounds in the treatment of ovarian cancer, strategically designed, large scale studies are warranted.

Self-assessment of morbidity following radical hysterectomy for cervical cancer

The aim of this study was to assess the magnitude of the morbidity following radical surgery for early stage cervical cancer. We performed a retrospective survey of all women who had undergone a radical hysterectomy and lymphadenectomy between the months of July 1995 and December 1996 inclusive at either the Royal Marsden or St George's Hospital (n =38), using a detailed questionnaire on bladder, ano-rectal and sexual function, both before and after treatment. Sixteen women (44.4%) received adjuvant radiotherapy. The mean interval between surgery and inquiry was 16.4% months (range 8-25 months). The mean age at the time of surgery was 40.5 years. Thirty-six out of 38 women contacted responded (94.7%). Overall 33 women (91.7%) reported new bladder, ano-rectal or sexual symptoms. Complaints of urinary incontinence, particularly of urge incontinence, and of voiding difficulties increased significantly after surgery (P <0.05). However, only 5.3% of women had sought treatment. Tenesmus increased significantly (P <0.05), while increases in diarrhoea and faecal incontinence were not statistically significant (P =0.051). Although 12.9% of women stated an improvement in their sex lives, 54.8% thought that their sex life was worse after treatment, and 12.9% of women had ceased sexual activity altogether. Of women of childbearing age 53.8% felt adversely affected by their loss of fertility. Bladder, ano-rectal and sexual symptoms are very common following radical hysterectomy for cervical cancer, with adverse effect on quality of life, and persist into the second year after treatment.

Emergency obstetric hysterectomy—an increasing incidence

Ten women underwent obstetric hysterectomy at St George's Hospital, London between 1992 and 1998, with an apparent seven-fold increase in incidence in recent years. All hysterectomies were performed as emergency procedures, with massive postpartum haemorrhage being the major indication for operation in nine cases. Abnormal placentation was the single commonest cause, seven cases being associated with previous caesarean section. There were no maternal or fetal mortalities, but major surgical complications, including urinary tract and vascular injury occurred in one case. In view of the increasing risk of obstetric hysterectomy following previous caesarean section, high risk cases associated with abnormal placentation may be identified using ultrasound, allowing appropriate pre-operative counselling regarding the risk of peripartum hysterectomy.

Pelvic nerve plexus trauma at radical and simple hysterectomy: a quantitative study of nerve types in the uterine supporting ligaments

OBJECTIVE

Using neuropeptide and enzyme markers to autonomic nerves, we sought to demonstrate and quantify the nerve types contained within the uterosacral ligaments (USLs) and cardinal ligaments (CLs) that are divided during radical hysterectomy (RH).

METHODS

Cross-sectional biopsies were collected from the lateral third of the USL and the CL in 24 women who had an RH for cervical cancer, and from the uterine insertion of these ligaments in 11 women who had a simple hysterectomy for benign disease. We applied indirect immunofluorescence with FITC-conjugated secondary antibodies, using polyclonal primary antibodies to neuropeptide markers that predominate within somatic and autonomic nerves, to show different populations of the following nerve types within the biopsies: neuropeptide Y (NPY) and tyrosine hydroxylase (TH) for sympathetic nerves; vasoactive intestinal polypeptide (VIP) for parasympathetic nerves; substance P (SP) for nociceptive and sensory-motor nerves; and calcitonin gene-related peptide (CGRP) for sensory and sensory-motor nerves. The percentage area of immunoreactivity (PAI), determined by a computer-assisted image analyzer attached to a fluorescent microscope, was used as an objective quantitative measure of nerve density. Confocal microscopy was used to determine the composition and spatial arrangement of nerve fibers in the ligaments.

RESULTS

The PAI was greater for all markers tested in both the USL and CL (P <.001) in RH compared with simple hysterectomy biopsies. For RH specimens, the PAI was greater for the sympathetic, sensory, and sensory-motor nerve markers in the USL compared with the CL (P <.01), but the PAI for VIP was similar (P >.05). Conversely, excluding the large trunks and associated ganglia, the free nerve fiber PAI in the CL was greater than that of the USL for all nerve markers (P <.001). The staining of peripheral autonomic ganglia and associated fibers, for NPY and TH, indicates that some sympathetic nerves are preganglionic with their cell bodies within the pelvic plexus.

CONCLUSIONS

Significantly more autonomic nerves are transected in the more lateral division of the uterine supporting ligaments during a radical hysterectomy than during a simple hysterectomy. Sympathetic, parasympathetic, sensory, and sensory-motor nerve types are present within the CL and USL. The proportions of each nerve type differ between the two ligaments, and sympathetic nerves in the USL are the single largest nerve type. The uterine supporting ligaments are a major pathway for autonomic nerves to the pelvic organs.

Pelvic nerve plexus trauma at radical hysterectomy and simple hysterectomy: the nerve content of the uterine supporting ligaments

BACKGROUND

A major cause of the pelvic morbidity after a radical hysterectomy (RH) is thought to be damage to the pelvic nerve plexus, but direct evidence is lacking. We set out to determine the nerve content of the uterosacral ligaments (USLs) and cardinal ligaments (CLs) at the level at which they are divided during a radical hysterectomy and a simple hysterectomy.

METHODS

Intraoperative cross-sectional biopsies were collected from the lateral third of the uterosacral ligaments (USLs) and cardinal ligaments (CLs) in 20 women undergoing radical hysterectomy (RH) and from the uterine insertion of these ligaments in 11 women undergoing a simple hysterectomy. Quantitative immunocytochemistry was utilized to demonstrate and quantify the nerve content of the uterine supporting ligaments at the level at which they are divided in a RH and in a simple hysterectomy. Indirect immunofluorescence staining of frozen cryostat sections was performed using primary antibodies to PGP 9.5 (a pan-neuronal marker). A computer-assisted image analyzer measured the percentage area of immunoreactivity (PAI) that was used to quantify the nerve density. Confocal microscopy was used to determine the composition and spatial arrangement of nerve fibers in the ligaments.

RESULTS

The PAI was significantly greater in the RH biopsies than in the simple hysterectomy biopsies, for both the CLs (P < 0.001) and the USLs (P < 0.001). In the RH biopsies, more nerve tissue was present in the USL than CL (P = 0.01), and compared with the CL more of the nerve fibers in the USL were concentrated in large trunks. Excluding these trunks and autonomic ganglia, the free nerve content of the USL was lower than that of the CL (P < 0.001). The presence of nerve trunks, autonomic ganglia, and free nerve fibers within the lateral third of the USL and CL is consistent with extension of the inferior hypogastric plexus along these ligaments to the pelvic organs.

CONCLUSIONS

The uterine supporting ligaments contain autonomic nerves and ganglia, as extensions of the inferior hypogastric plexus. The USLs have a greater nerve density than the CLs. Because RH disrupts more nerve tissue than a simple hysterectomy, these data provide further evidence for the neurogenic etiology of pelvic morbidity after RH.

Psammoma bodies on routine cervical smear

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