Prognostic significance of uPA and uPAR expression in patients with cervical cancer undergoing radiotherapy

Positron emission computed tomography targeting urokinase plasminogen activator receptor (uPAR) in cancer: a systematic review

INTRODUCTION

To provide an overview of the available literature data on clinical applications of positron emission tomography (PET) targeting the urokinase-type plasminogen activator receptor in oncology.

METHODS

A literature search was conducted in PubMed, Web of Science and Scopus databases up to June 2023. The results were presented according to the PRISMA guidelines. The quality of the studies was assessed using the Critical Appraisal Skill Program checklist.

RESULTS

Seven papers were selected for final analysis, involving 266 patients with solid tumors who underwent PET with uPAR-ligands. Thematic areas identified include feasibility studies (n = 2) on the safety, pharmacokinetics, and dosimetry of uPAR-targeting radiopharmaceuticals; uPAR-directed imaging in head and neck cancer (n = 2); uPAR PET in prostate cancer (n = 2); and the investigation of uPAR in neuroendocrine neoplasms (n = 1). Six of the seven studies used the radiopharmaceutical [68Ga]Ga-NOTA-AE105 while one study used [64Cu]Cu-DOTA-AE105. The studies showed protocol homogeneity, with static PET imaging at 20 minutes. The quality assessment revealed limitations such as small cohorts and the fact that all studies were performed by a single research group.

CONCLUSIONS

uPAR-PET appears to be a promising imaging tool in well-selected oncological settings, but it needs to be validated by multicentre collaboration.

Compared to preoperative plasma levels post-operative urokinase-type plasminogen activator-1 levels are persistently elevated for 6 weeks after minimally invasive colorectal resection

Background

Urokinase-type plasminogen activator-1 (uPA) is a serine protease that converts plasminogen to plasmin after binding to uPA receptor (uPAR). Plasmin catalyzes the regeneration of basement membrane, extracellular matrix, and other tissues. uPA alone and with plasmin leads to activation of angiogenic growth factors that impact tumor cell proliferation, adhesion, and migration. uPA over expression has been noted in colorectal cancer (CRC) and high tissue levels have been correlated with prognosis. uPA/uPAR promotes immune cell activation in healing surgical wounds and may alter perioperative uPA plasma levels. Postoperative (postop) plasma levels, if elevated, may impact the early growth of residual metastases. The impact of minimally invasive colorectal resection (MICR) surgery for CRC on plasma uPA levels is unknown. This study's aim was to measure plasma uPA levels during the first postop month.

Methods

CRC patients undergoing MICR who enrolled in an Institutional Review Board (IRB) approved data/plasma bank for whom adequate plasma was available were included in the study. Patients who had chemotherapy or radiotherapy within 4 weeks, those who received blood transfusions perioperatively and immunosuppressed patients were excluded. Clinical and pathological data were prospectively collected as were blood samples preoperatively, postop day (POD) 1, 3 and at least 1 late time point between POD 7-41. Plasma was isolated and stored at -80 ℃. Late samples were bundled into 7-day blocks and considered as single time points. Total uPA levels (ng/mL) were analyzed in duplicate via enzyme-linked immunosorbent assay (ELISA) and results reported as mean ± standard deviation (SD). The Wilcoxon paired t-test was used for analysis.

Results

Ninety-three patients undergoing MICR for CRC [colonic 68%; rectal 32%; average age 65.6 years, laparoscopic 63%, hand-assisted minimally invasive surgery (MIS) 37%] who met criteria were studied. Cancer stage breakdown was; stage I, 30%, stage II, 29%, stage III, 34%, stage IV, 7%. The median preoperative (preop) uPA plasma level (ng/mL) was 529.8 [95% confidence interval (CI): 462.8, 601.1] (n=93). Significant elevations in median levels vs. preop were present during POD 3 (542.8, 95% CI: 518.8, 597.3, n=86, P=0.003), POD 7-13 (688.1, 95% CI: 591.7, 753.0, n=72, P<0.001), POD 14-20 (764.9, 95% CI: 704.1, 911.6, n=27, P<0.001), POD 21-27 (685.6, 95% CI: 443.8, 835.8, n=15, P<0.001), and on POD 28-41 (800.3, 95% CI: 626.9, 940.6, n=21, P<0.001). The colon cancer subgroup's preop and POD 14-20 median results were significantly higher than the corresponding rectal cancer results; otherwise, at the other 5 postop time points there were no significant differences between the rectal and colon cancer subgroups. In addition, no association was found between cancer stage and preop uPA levels and no significant differences were found in postop uPA levels between the hand-assisted laparoscopic group and the lap assisted subgroup at any of the postop time points.

Conclusions

Persistently elevated plasma uPA levels at 5/6 postop time point (P<0.05), in combination with other previously demonstrated long duration proangiogenic plasma protein changes, may render the plasma proangiogenic within the period of the first month post-surgery and may promote angiogenesis within the residual tumor foci. The clinical significance pertaining to these changes, if any, is uncertain and remains to be proven.

Delivery of Melittin as a Lytic Agent via Graphene Nanoparticles as Carriers to Breast Cancer Cells

Melittin, as an agent to lyse biological membranes, may be a promising therapeutic agent in the treatment of cancer. However, because of its nonspecific actions, there is a need to use a delivery method. The conducted research determined whether carbon nanoparticles, such as graphene and graphene oxide, could be carriers for melittin to breast cancer cells. The studies included the analysis of intracellular pH, the potential of cell membranes, the type of cellular transport, and the expression of receptor proteins. By measuring the particle size, zeta potential, and FT-IT analysis, we found that the investigated nanoparticles are connected by electrostatic interactions. The level of melittin encapsulation with graphene was 86%, while with graphene oxide it was 78%. A decrease in pHi was observed for all cell lines after administration of melittin and its complex with graphene. The decrease in membrane polarization was demonstrated for all lines treated with melittin and its complex with graphene and after exposure to the complex of melittin with graphene oxide for the MDA-MB-231 and HFFF2 lines. The results showed that the investigated melittin complexes and the melittin itself act differently on different cell lines (MDA-MB-231 and MCF-7). It has been shown that in MDA-MD-231 cells, melittin in a complex with graphene is transported to cells via caveolin-dependent endocytosis. On the other hand, the melittin-graphene oxide complex can reach breast cancer cells through various types of transport. Other differences in protein expression changes were also observed for tumor lines after exposure to melittin and complexes.

Urokinase-type plasminogen activator receptor (uPAR) assessed by liquid biopsies and PET/CT for prognostication in head and neck cancer patients

Strong prognostic biomarkers are lacking regarding the stratification of treatment and surveillance regimens in head and neck squamous cell carcinoma (HNSCC). The study aimed to assess the prognostic value of soluble urokinase-type plasminogen activator receptor in plasma (suPAR) compared to evaluation by uPAR-positron-emission-tomography (PET) in HNSCC patients. Plasma from 19 controls and 49 HNSCC patients referred to curatively intended radiotherapy (2017-2021) was collected pre-treatment and post-treatment (n = 37). Information on uPAR-PET was available from previous evaluation. Patient median suPAR was significantly higher pre- and post-treatment compared to controls (p = 0.013, p = 0.003) and increased significantly during radiotherapy (p = 0.003). Pre-treatment suPAR did not predict survival outcomes. Post-treatment suPAR significantly predicted RFS (HR = 6.67 (95% CI 1.44-30.9) p = 0.015), but not OS (HR = 3.29 (95% CI 0.882-12.3) p = 0.076) in univariate analysis. RFS prediction was maintained for post-treatment suPAR in multivariate analysis, including TNM-stage (HR = 6.62 (95% CI 1.40-31.4) p = 0.017). Pre-treatment uPAR-PET/CT and post-treatment suPAR was available in 24 patients. High uPAR-estimates on both modalities was significantly associated with poor RFS compared to patients with low uPAR-estimates (log-rank, p = 0.008). Patients with discordant uPAR-estimates (one-low/one-high) were at intermediate risk, although non-significant (p = 0.131). In conclusion, pre-treatment suPAR did not predict RFS or OS. Pre-treatment uPAR-PET and post-treatment suPAR predicted RFS.

Melatonin Modulation of Radiation-Induced Molecular Changes in MCF-7 Human Breast Cancer Cells

Radiation therapy is an important component of cancer treatment scheduled for cancer patients, although it can cause numerous deleterious effects. The use of adjuvant molecules aims to limit the damage in normal surrounding tissues and enhance the effects of radiation therapy, either killing tumor cells or slowing down their growth. Melatonin, an indoleamine released by the pineal gland, behaves as a radiosensitizer in breast cancer, since it enhances the therapeutic effects of ionizing radiation and mitigates side effects on normal cells. However, the molecular mechanisms through which melatonin modulates the molecular changes triggered by radiotherapy remain mostly unknown. Here, we report that melatonin potentiated the anti-proliferative effect of radiation in MCF-7 cells. Treatment with ionizing radiation induced changes in the expression of many genes. Out of a total of 25 genes altered by radiation, melatonin potentiated changes in 13 of them, whereas the effect was reverted in another 10 cases. Among them, melatonin elevated the levels of PTEN and NME1, and decreased the levels of SNAI2, ERBB2, AKT, SERPINE1, SFN, PLAU, ATM and N3RC1. We also analyzed the expression of several microRNAs and found that melatonin enhanced the effect of radiation on the levels of miR-20a, miR-19a, miR-93, miR-20b and miR-29a. Rather surprisingly, radiation induced miR-17, miR-141 and miR-15a but melatonin treatment prior to radiation counteracted this stimulatory effect. Radiation alone enhanced the expression of the cancer suppressor miR-34a, and melatonin strongly stimulated this effect. Melatonin further enhanced the radiation-mediated inhibition of Akt. Finally, in an in vivo assay, melatonin restrained new vascularization in combination with ionizing radiation. Our results confirm that melatonin blocks many of the undesirable effects of ionizing radiation in MCF-7 cells and enhances changes that lead to optimized treatment results. This article highlights the effectiveness of melatonin as both a radiosensitizer and a radioprotector in breast cancer. Melatonin is an effective adjuvant molecule to radiotherapy, promoting anti-cancer therapeutic effects in cancer treatment. Melatonin modulates molecular pathways altered by radiation, and its use in clinic might lead to improved therapeutic outcomes by enhancing the sensitivity of cancerous cells to radiation and, in general, reversing their resistance toward currently applied therapeutic modalities.