FOXM1 and polo-like kinase 1 are co-ordinately overexpressed in patients with gastric adenocarcinomas

BACKGROUND

Gastric cancers present late in life with advanced disease and carry a poor prognosis. Polo-like Kinase 1 (PLK1) is a mitotic kinase with regulatory functions during G2/M and mitosis in the cell cycle. In mammalian cells, there is an intricate co-regulatory relationship between PLK1 and the forkhead transcription factor FOXM1. It has been demonstrated that individually either PLK1 or FOXM1 expression predicts poorer survival. However, the co-expression of both of these markers in gastric adenocarcinomas has not been reported previously.

METHODS

We aimed to assess the expression of PLK1 and FOXM1 in Gastric adenocarcinomas in a Western Population, to examine whether there is a relationship of PLK1 to FOXM1 in cancer samples. We assess both the protein and mRNA expression in this patient population by Tissue Microarray immunohistochemistry and RT-PCR.

RESULTS

Immunohistochemistry was performed on biopsy samples from 79 patients with gastric cancer. Paired normal controls were available in 47 patients. FOXM1 expression was significantly associated with gastric adenocarcinoma (p = 0.001). PLK1 and FOXM1 co-expression was demonstrated in 6/8 (75 %) tumours when analysed by RT-PCR. FOXM1 is overexpressed in a large proportion of gastric carcinomas at the protein level and FOXM1 and PLK1 are concomitantly overexpressed at the mRNA level in this cancer type.

CONCLUSIONS

This study has demonstrated that FOXM1 and its target gene PLK1 are coordinately overexpressed in a proportion of gastric adenocarcinomas. This suggests that chemotherapeutic treatments that target this pathway may be of clinical utility.

Radiation enteritis leading to intestinal failure: 1994 patient-years of experience in a national referral centre

BACKGROUND/OBJECTIVES

Chronic radiation enteritis (RE) has been reported in up to 20% of patients receiving pelvic radiotherapy and can lead to intestinal failure (IF), accounting for 3.9% of new registrants for home parenteral nutrition (HPN) in the UK annually. Our aim is to report nutritional and survival outcomes for patients with RE referred to a national IF unit.

SUBJECTS/METHODS

A retrospective study of all new admissions over a 13-year period at the Intestinal Failure Centre, Manchester, UK. Data are presented as median (range).

RESULTS

Twenty-three (3.8%) of 611 patients were admitted with IF secondary to RE. The primary site of malignancy was genitourinary in 17 (74%) patients. Radiotherapy was administered 9.5 (1-42) years previously. Patients underwent 2 (1-5) laparotomies prior to intestinal failure unit (IFU) admission. Twelve (52%) patients were admitted with intestinal obstruction and 11 (48%) with intractable weight loss and/or high output fistulae/stomas. Additional conditions contributing to IF were noted in 11 (48%) patients. Twenty-two (96%) patients had 2 (1-5) laparotomies prior to IFU referral. At discharge, 5 (22%) patients resumed oral diet without the need for artificial nutrition support, 3 (13%) required enteral feeding and 13 (56%) commenced HPN. The 10-year survival of the patient cohort was 48.2%.

CONCLUSIONS

Surgical intervention is infrequently required, whereas the majority of patients with IF secondary to RE require long-term HPN. The judicious use of surgery in selected patients, coupled with an aggressive medical strategy to detect and treat contributing factors, and optimal enteral feeding may allow a modest proportion of patients with IF secondary to RE to achieve independence from PN.

Review article: the management of long-term parenteral nutrition

BACKGROUND

Home parenteral nutrition (HPN) is currently the management of choice for patients with chronic intestinal failure.

AIM

To summarise the major issues in delivering long-term parenteral nutrition (>3 months) and assess outcome as per complications, mortality and quality of life. To assess the evidence for the therapeutic use of trophic factors such as teduglutide and to review evolving therapeutic options in the treatment of chronic intestinal failure.

METHODS

A literature search using PubMed and MEDLINE databases was performed.

RESULTS

Safe delivery of HPN relies upon individualised formulations of parenteral nutrition administered via carefully maintained central venous catheters by trained patients or carers, supported by a skilled multidisciplinary team. Early diagnosis and treatment of complications including catheter-associated blood stream infection (reported incidence 0.14-0.83 episodes/patient-year on HPN) and central venous thrombosis (reported incidence 0.03 episodes/patient-year) is important to minimise mortality and morbidity. There is a significant variation in the reported incidence of both hepatobiliary complications (19-75%) and advanced liver disease (0-50%). Five-year survival rates in large centres are reported between 60% and 78% with survival primarily related to underlying diagnosis. Long-term survival remains higher on HPN than with intestinal transplantation. The role of intestinal lengthening procedures is yet to be validated in adults.

CONCLUSIONS

Home parenteral nutrition delivered by skilled nutrition teams has low incidences of catheter-related complications. Most deaths relate to the underlying disease. Therapies such as teduglutide and small bowel transplantation appear promising, but home parenteral nutrition appears likely to remain the bedrock of management in the near term.

The FOXM1-PLK1 axis is commonly upregulated in oesophageal adenocarcinoma

BACKGROUND

The transcription factor FOXM1 is an important regulator of the cell cycle through controlling periodic gene expression during the G2 and M phases. One key target for FOXM1 is the gene encoding the protein kinase PLK1 and PLK1 itself acts in a positive feedback loop to phosphorylate and activate FOXM1. Both FOXM1 and PLK1 have been shown to be overexpressed in a variety of different tumour types.

METHODS

We have used a combination of RT-PCR, western blotting, tissue microarrays and metadata analysis of microarray data to study whether the FOXM1-PLK1 regulatory axis is upregulated and operational in oesophageal adenocarcinoma.

RESULTS

FOXM1 and PLK1 are expressed in oesophageal adenocarcinoma-derived cell lines and demonstrate cross-regulatory interactions. Importantly, we also demonstrate the concomitant overexpression of FOXM1 and PLK1 in a large proportion of oesophageal adenocarcinoma samples. This co-association was extended to the additional FOXM1 target genes CCNB1, AURKB and CKS1. In a cohort of patients who subsequently underwent surgery, the expression of several FOXM1 target genes was prognostic for overall survival.

CONCLUSIONS

FOXM1 and its target gene PLK1 are commonly overexpressed in oesophageal adenocarcinomas and this association can be extended to other FOXM1 target genes, providing potentially important biomarkers for predicting post-surgery disease survival.