Plasma Prokineticin 1, a prognostic biomarker in colorectal cancer patients with curative resection: a retrospective cohort study

BACKGROUND

Prokineticin 1 (PROK1) was reported as an angiogenic factor, which is associated with tumor progression, cell invasion, and metastasis in colorectal cancer. Although the association between PROK1 expression in primary cancer lesion and patient prognosis was reported, it is unclear whether plasma PROK1 concentration may be a predictive factor in colorectal cancer patients. This study investigated the association between PROK1 concentration in plasma and prognosis in colorectal cancer patients.

METHODS

We measured preoperative PROK1 plasma levels using ELISA method, while PROK1 expression in primary cancer lesion was evaluated using immunohistochemistry (IHC). The association between plasma PROK1 levels and cancer-related survival rate (CRS) was evaluated. Additionally, we examined whether simultaneous PROK1 expression in both primary cancer lesions and plasma was correlated with CRS. The cancer-related survival rate was calculated using the Kaplan-Meier method, and survival estimates were compared using the log-rank test.

RESULTS

We have gathered eligible 130 CRC patients retrospectively. Out of 130 patients, 61 (46.9%) were positive on IHC in primary cancer, and 69 (53.1%) were negative, while 43 (33.1%) had high-value PROK1 in plasma. Out of these 43, 30 (25.4%) also had concomitant higher IHC expression in primary cancer. The plasma PROK1 levels tended to increase with advancing stages. The plasma PROK1-positive group had a lower 5-year CRS than the negative group (63.6% vs. 88.2%; P = 0.006). Additionally, simultaneous PROK1 expression was associated with a more significant decrease of 5-year CRS than both negative groups in all stages (76.2% vs. 92.5%; P = 0.003) and stage III (59.3% vs. 84.5%; P = 0.047). Multivariate analysis showed simultaneous PROK1 expression was independently associated with worse CRS (HR, 1.97; 95% CI 1.20‑3.24, P < 0.01).

CONCLUSION

PROK1 expression in preoperative plasma reflects poor prognosis in patients undergoing curative resection for colorectal cancer. The plasma PROK1 level may be a potential predictive marker, especially in stage III colorectal cancer patients.

Prokineticin 1-prokineticin receptor 1 signaling promotes angiogenesis in the porcine endometrium during pregnancy†

Pregnancy establishment in mammals, including pigs, requires proper communication between embryos and the maternal reproductive tract. Prokineticin 1 (PROK1) has been described as a secretory protein with pleiotropic functions and as a novel tissue-specific angiogenic factor. However, despite the studies performed mainly on human cell lines and in mice, the function of PROK1 in the endometrium during early pregnancy is still not fully elucidated. We hypothesized that PROK1 contributes to pregnancy establishment in pigs. The present study is the first to report that the expression of PROK1 and its receptor (PROKR1) is elevated in the porcine endometrium during the implantation and early placentation period. PROK1 protein was detected mainly in luminal epithelial cells, glandular epithelial cells, and blood vessels in the endometrium. Using the porcine in vivo model of unilateral pregnancy, we revealed that conceptuses induced the endometrial expression of PROK1 and PROKR1. Moreover, the embryonic signal, estradiol-17β, as well as progesterone, stimulated the endometrial expression of PROK1 and PROKR1. We also evidenced that PROK1-PROKR1 signaling supports endometrial angiogenesis in pigs. The PROK1-stimulated proliferation of primary porcine endometrial endothelial (PEE) cells involved PI3K/AKT/mTOR, MAPK, cAMP, and NFKB signaling pathways. Furthermore, PROK1 via PROKR1 promoted the formation of capillary-like structures by PEE cells. PROK1 also stimulated VEGFA and PGF2α secretion, which in turn may indirectly support angiogenic changes within endometrial tissue. In summary, our study suggests that PROK1 acts as an embryonic signal mediator that regulates endometrial angiogenesis and secretory function during the implantation and early placentation period in pigs.

Relationship between second-trimester amniotic fluid levels of Prokineticin-1 and Matrix Metalloproteinase-2 with adverse pregnancy outcome

To investigate the levels of Prokineticin-1 (PROK1) and matrix metalloproteinase-2 (MMP-2) in second-trimester amniotic fluid (AF). AF samples were investigated in 81 patients. AF-PROK1 and AF-MMP-2 were not significantly associated with adverse pregnancy outcomes (preeclampsia, intrauterine growth retardation, spontaneous preterm birth, gestational diabetes, gestational hypertension). AF-PROK1 levels in patients with abnormal first-trimester screening were significantly higher than those who underwent amniocentesis due to abnormal second-trimester screening tests (p = .04). AF-PROK1 or AF-MMP-2 do not have a role in the prediction of adverse pregnancy outcomes.

Clinical and prognostic significance of prokineticin 1 in human gliomas

The objective of this study was to explore the expression and the clinical and prognostic significance of prokineticin 1 (PROK1) in human gliomas. The expression of PROK1 in 60 patients with glioma and in eight control cases (patients with traumatic brain injury) by immunohistochemistry (IHC). The associations between the differences in expression and pathology grades were analyzed statistically. The positive rates of PROK1 expression in normal brain and glioma tissue were 25.0% (2/8) and 93.3% (56/60), respectively. PROK1 expression in glioma tissue was higher than that in normal tissue (P<0.05). The positive rates of PROK1 expression in low-grade gliomas (LGGs, grades I and II) and high-grade gliomas (HGGs, grades III and IV) were 66.7% (8/12) and 100% (48/48), respectively, the positive rates in HGG were higher than those in LGG (P<0.01). PROK1 is an angiogenic growth factor that is related with metastatic ability of tumor, we also correlated PROK1 expression with NFAT expression. Expression of PROK1correlated significantly with expression of NFAT (r=0.524, P<0.01), but not with patient sex and age. Glioma patients with higher expressing PROK1 had a significantly shorter progression-free survival time, increasing levels of PROK1 expression significantly correlated with reduced survival times when all patients with glioma were considered (P<0.01). These results suggested that PROK1 positivity and protein expression levels are of significant clinical and prognostic value in human gliomas, which significantly correlates with the survival in gliomas, PROK1 may regulate the progression of glioma via the NFAT pathway.

Prokineticin 1 expression in gastrointestinal tumors

AIM

We studied prokineticin 1 (PROK1) expression in human gastrointestinal carcinomas by immunohistochemistry.

MATERIALS AND METHODS

PROK1 expression was examined in human gastrointestinal cancer cell lines and primary gastrointestinal lesions. In addition the relationship between the number of blood vessels and PROK1 expression in these primary lesions was examined.

RESULTS

PROK1 expression was observed in gastrointestinal cancer cell lines. PROK1 expression was not observed in healthy gastrointestinal mucosa, but was observed in the primary lesions in 23 out of 98 (31.6%) patients with colorectal cancer, 19 out of 55 (34.5%) patients with gastric cancer, and 5 of 10 (50%) patients with cancer of the small intestine. PROK1 expression was observed in many patients with advanced gastrointestinal cancer. The number of blood vessels in PROK1-positive primary gastrointestinal lesions was higher than that in PROK1-negative primary lesions.

CONCLUSION

PROK1 expression might be related to the extent of malignancy in gastrointestinal cancer.