Increased alpha-fetoprotein receptor in the serum of patients with early-stage breast cancer

Strategies for five tumour markers in the screening and diagnosis of female breast cancer

Objective

This study evaluated the diagnostic value of different combinations of five commonly used tumour markers and screened the best combination of tumour markers.

Methods

Regression analysis was used to evaluate 185 patients with suspected breast cancer admitted to Mianyang Central Hospital from January 2020 to December 2021. The differences of five tumour markers between a breast cancer group and a benign lesion group were analysed. The sensitivity and specificity of five tumour markers were compared.

Results

Of 185 patients with suspected breast cancer, 108 patients had breast cancer and 77 patients had benign breast tumours. The detection results of carcinoembryonic antigen (CEA), alpha fetoprotein (AFP), carbohydrate antigen 125 (CA125), carbohydrate antigen 199 (CA199) and carbohydrate antigen 153 (CA153) in patients with breast cancer were significantly higher than those in patients with benign breast tumours. In the analysis of the single-detection results of tumour markers, CEA had the highest sensitivity (23.94%), CA153 had the highest specificity (96.43%), AFP had the highest accuracy (47.66%) and CA153 had the highest area under the curve (AUC) value (0.727). With the increase of parallel indicators, the sensitivity, accuracy and AUC value increased in turn, and the increase was obvious in the front. The increase began to slow down after the three parallel indicators. Among the different combinations of three parallel detections of breast cancer tumour markers, the highest sensitivity was AFP + CEA + CA153 (83.46%), the highest accuracy was AFP + CEA + CA153 and AFP + CA153 + CA125 (80.25%), and the highest AUC was CEA + CA125 + CA199 (0.922).

Conclusion

AFP, CA153 and CA199 are recommended for clinical diagnosis of breast cancer. In routine physical examination and early breast cancer screening, the optimal combination of AFP + CEA + CA153 three parallel tests is recommended.

First report of the unique expression of RECAF (receptor for alfa feto-protein) in adult B-NHL/CLL patients

Background

Lymphoproliferative disorders (LPDs) are a heterogeneous group of diseases characterized by an uncontrolled production of monoclonal lymphocytes. RECAF is the receptor for alpha-fetoprotein, which is re-expressed on malignant cells, thus serving as a broad-spectrum tumor marker.

Methods

The current study is a retrospective study carried out on 200 archival bone marrow trephine biopsy specimens [60 normal control (NC), 38 pathological control (PC) and 102 lymphoproliferative diseases (LPD) specimens]. RECAF expression was assessed using immunohistochemistry.

Results

The percentage of cells that are positive for RECAF was significantly higher in the LPD group than in the NC group (P=0.007), while there was no significant difference between non-Hodgkin lymphoma (NHL) patients and PC regarding the number of RECAF positive cells (P=0.1). RECAF showed a unique expression pattern among the different subtypes of LPD. None of the hairy cell leukemia (HCL) expressed RECAF, while the highest percentage was seen in follicular lymphoma (FL) and diffuse large B cell lymphoma (DLBCL) (P=0.001). Compared to routine histopathology, RECAF was more sensitive in detecting bone marrow (BM) infiltration in FL, mantle cell lymphoma (MCL), and DLBCL (P=0.01).

Conclusion

RECAF is significantly expressed in the BM of NHL/chronic lymphocytic leukemia (CLL) patients. RECAF shows a unique expression pattern among the different subtypes of LPD. Furthermore, RECAF may help to detect bone marrow infiltration in lymphoma cells. This may help in the diagnosis, follow-up, and targeting of LPD.

Activated Wnt signaling promotes growth and progression of AFP-producing gastric cancer in preclinical models

Background

Characterized by elevated AFP levels in serum, AFP-producing gastric cancer (APGC) is a very special type of gastric cancer (GC) that is difficult to treat and has poor prognosis. However, little is known about the role of AFP in GC, which was investigated in this study with in vitro and in vivo experiments.

Methods

APGC cells were established with lentivirus infection and validated by PCR assay and ELISA in HCG27 and AGS cells. Cell growth, migration, and invasion were determined by CCK8, transwell assays, and animal experiments. RNA sequencing, Western blot, dual-luciferase-reporter assays, and RNA interference were employed to understand mechanisms underlying AFP activity, followed by therapeutic investigations for APGC.

Results

APGC cells featured significantly increased AFP levels in cellular supernatants. AFP potentiated growth and aggression in GC cell lines and their derived xenografts. Wnt-signaling activation was responsible for AFP function, indicated by decreased Axin 1 and pGSK3β, followed by cascade activation of β-catenin, downstream transcription factors TCF1/TCF7, and the target gene – c-Myc. Wnt-signaling blockade by Axin 1 rescue or pathway inhibitor XAV939 reversed AFP function, suggesting the potential therapeutic value of APGC.

Conclusion

AFP played a critical role in APGC through activating Wnt signaling, and targeting Wnt pathways might be a promising strategy against APGC.

Binding characterization of the targeting drug AIMPILA to AFP receptors in human tumor xenografts

The main objective of this study was the characterization of preclinical tumor models based on their expression of alpha-fetoprotein receptor (RECAF) for targeting cancer cells with a new non-covalent complex (AIMPILA) containing alpha-fetoprotein as the carrier and Atractyloside as an apoptosis-inducing agent. For that purpose, we measured the amount of RECAF in the homogenates of the grafted tumors T47D and SW620 and in HepG2 cell extracts. We also determined the alpha-fetoprotein binding specificity of the targeting drug AIMPILA using a solid-phase chemiluminescent assay with AIMPILA-Acrdidinium. We found that RECAF is practically absent from healthy mice tissues (100 Units/mg) where in malignant cells, the amount of alpha-fetoprotein receptors follows this order: T47D (9152 Units/mg) > HepG2 (4865 Units/mg) > SW620 (2839 Units/mg). This agrees with our findings regarding AIMPILA-induced tumor growth inhibition (T47D (T/C = 22%) > HepG2 (T/C = 51%) > SW620 (T/C = 70%), where T/C is the ratio of tumor volume in treated vs control animals). Our results demonstrate that the therapeutic response to the targeting drug AIMPILA strongly depends on the RECAF expression by human tumors and confirms the choice of the tumor models used for an AIMPILA preclinical study.

Antibody to human α-fetoprotein inhibits cell growth of human hepatocellular carcinoma cells by resuscitating the PTEN molecule: in vitro experiments

It has been proposed that α-fetoprotein (AFP) is a new member of the intracellular signaling molecule family of the phosphoinositide 3-kinase (PI3K)/AKT signaling pathway via interaction with the phosphatase and tensin homolog (PTEN). In this study, the effects of anti-human AFP antibody on the functions of PTEN were examined using an AFP-producing human hepatoma cell line. The antibody caused significant inhibition of cell growth, compared to a normal IgG control, with the accumulation of intracellular immune complexes followed by significant reduction of cytosolic functional AFP. Decrease in the amount of AKT phosphorylated on serine (S) 473 indicated that PI3K/AKT signaling was suppressed in the cells. S380-phosphorylated PTEN increased markedly by the second day after antibody treatment, with slight but significant increase in the PTEN protein level. Since phosphorylation at S380 is critical for PTEN stability, the increase in S380-phosphorylated PTEN indicated maintenance of the number of PTEN molecules and the related potential to control PI3K/AKT signaling. p53 protein (P53) significantly, but slightly increased during antibody treatment, because PTEN expression increased the stability and function of P53 via both molecular interactions. P53 phosphorylated at S20 or at S392 dramatically increased, suggesting an increase in the stability, accumulation and activation of P53. Glucose transporter 1 (GLUT1) increased immediately after antibody treatment, pointing to a deficiency of glucose in the cells. Immunofluorescence cytology revealed that antibody-treatment re-distributed GLUT1 molecules throughout the cytoplasm with a reduction of their patchy localization on the cell surface. This suggested that translocation of GLUT1 depends on the PI3K/AKT pathway, in particular on PTEN expression. Antibody therapy targeted at AFP-producing tumor cells showed an inhibitory effect on the PI3K/AKT pathway via the liberation, restoration and functional stabilization of PTEN. PTEN simultaneously induced both P53 activation and intracellular translocation of GLUT1, since these are closely associated with PTEN.

The use of α-fetoprotein for the delivery of cytotoxic payloads to cancer cells

One approach to improving the activity of anticancer drugs is to bind them to the human α-fetoprotein (HAFP) that recognizes the tumor-associated cell-surface HAFP receptor. A drug can be bound to the HAFP by covalent conjugation or within a non-covalent complex. Specially designed linkers couple cytotoxins to the HAFP and ensure the stability of the HAFP-drug conjugate in the circulation and the activation of the drug in the cancer cell. On the other hand, AFP-drug non-covalent complexes can exploit the natural role of the AFP as a nutrition delivery "shuttle". In this article we review the design of HAFP-drug conjugates and AFP-drug complexes and their potential uses.

Review of the adenocarcinoma cell surface receptor for human alpha-fetoprotein; proposed identification of a widespread mucin as the tumor cell receptor

The identification of a tumor cell receptor for alpha-fetoprotein (AFP) has long been sought in the field of medicine. The uptake and endocytosis of AFP by rat tumor cells in 1983 sparked a series of confirmatory reports which were extended to include multiple tumor types in rats, mice, and humans. The following year, French investigators characterized the binding properties of the AFP receptor but they did not purify and characterize the receptor. It was not until 1991-1992 that an AFP receptor was partially purified and characterized from both human monocytes and breast cancer cells. By 1993, monoclonal antibodies had been raised against the "AFP receptor" derived from breast cancer extracts with claims that the receptor was a widespread oncoprotein biomarker for cancer. To date, that receptor has yet to be identified due to its complex multimeric structure and carbohydrate composition. The present report will review the literature of the multiple AFP receptors previously including their cellular uptake, transmembrane passage, and partial biochemical characterization. . In addition, evidence derived from computer modeling, proteolytic/fragmentation cleavage patterns, domain structure analysis, and protein binding software analysis will be presented in a proposed identification of a widespread protein/gene family of transmembrane proteins which fits many, if not most, of the criteria attributed to the AFP receptor. The proposed receptor protein family is tentatively identified as an epithelial cell surface mucin constituting one (or more) of many classes of single-pass transmembrane proteins. Present data do not support the concept that the AFP receptor is a "universal" tumor receptor and/or biomarker, but rather a widespread mucin protein that functions primarily in protecting and lubricating epithelial mucosal layers, and engaging in signal transduction; the mucin only binds AFP as a molecule serving in a subordinate or ancillary function.