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Background: The anti-cancer activity of some lactic acid bacterial strains is well documented in several kinds of literatures. Lactobacillus strains have received considerable attention as a beneficial microbiota. The aim of this study is to evaluate the effects of anti-tumor activities of L. acidophilus ATCC4356 culture supernatants on the MCF-7 human breast cancer cells. Materials and Methods: The anti-cancer effects of 24h and 48h culture supernatants at various concentrations (1.25, 2.5, 5, 10 and 20 μg/ml) were determined by various in vitro and in vivo assays including MTT, tumor volume measurement as well as 99mTc-MIBI biodistribution in MCF-7 tumor bearing nude mice and histopathology test. For evaluation of the related mechanism of action, quantitative PCR was conducted. Results: The 48h culture supernatants at 10 and 20 μg/ml exhibited significant in vitro inhibition of MCF-7 cell proliferation. However, this inhibition was not observed for HUVEC human endothelial normal cells. Q-PCR indicated that treatment by the supernatant led to a significant downregulation of VEGFR (~0.009 fold) and Bcl- 2 (~ 0.5 fold) and upregulation of p53 (~ 1.3 fold). In vivo study using MCF-7 xenograft mouse models demonstrated a reduction in tumor weight and volume by both 24h and 48h supernatants (2 mg/kg) after 15 days. According to the 99mTc-MIBI biodistribution result, treatment of MCF-7 bearing nude mice with both 24h and 48h supernatant (2mg/kg) led to a significant decrease in tumor uptake compared with the control group. Conclusion: These results suggest that the culture supernatants of L. acidophilus ATCC4356 at suitable concentrations can be considered as a good alternative nutraceutical with promising therapeutic indexes for breast cancer.

Extensive angiogenesis is a characteristic feature in the synovial tissue of rheumatoid arthritis (RA) from a very early stage of the disease onward and constitutes a crucial event for the development of the proliferative synovium. This process is markedly intensified in patients with prolonged disease duration, high disease activity, disease severity, and significant inflammatory cell infiltration. Angiogenesis is therefore an interesting target for the development of new therapeutic approaches as well as disease monitoring strategies in RA. To this end, nuclear imaging modalities represent valuable non-invasive tools that can selectively target molecular markers of angiogenesis and accurately and quantitatively track molecular changes in multiple joints simultaneously. This systematic review summarizes the imaging markers used for single photon emission computed tomography (SPECT) and/or positron emission tomography (PET) approaches, targeting pathways and mediators involved in synovial neo-angiogenesis in RA.

Gastric cancer (GC) is still ranked fourth among malignant cancers and remained as the second leading cause of cancer related death. There is mounting evidence that emphasizes on the need for further investigation on the specific receptors overexpression roles in GC progression. Low efficiency and impotence of the common methods for targeting gastric tumorigenesis and related metastases are enough to convince researchers to continue their investigation on new approaches of effective GC targeting. Due to the suitable characteristics of peptides, such as high affinity and specificity, they have great potential for cancer cell targeting. Overexpression of specific targets in GC can facilitate the application of peptide-based pharmaceuticals for effective tumor targeting and therapy and early diagnosis with help of fluorescents or radionuclides. In this review article, we paid particular attention to the characterization of peptide-based pharmaceuticals and radiopharmaceuticals that have been investigated in recent years for GC diagnosis and therapy.

Non-invasive imaging modalities constitute an increasingly important tool in diagnostic and therapy response monitoring of patients with autoimmune diseases, including rheumatoid arthritis (RA). In particular, macrophage imaging with positron emission tomography (PET) using novel radiotracers based on differential expression of plasma membrane proteins and functioning of cellular processes may be suited for this. Over the past decade, selective expression of folate receptor β (FRβ), a glycosylphosphatidylinositol-anchored plasma membrane protein, on myeloid cells has emerged as an attractive target for macrophage imaging by exploiting the high binding affinity of folate-based PET tracers. This work discusses molecular, biochemical and functional properties of FRβ, describes the preclinical development of a folate-PET tracer and the evaluation of this tracer in a translational model of arthritis for diagnostics and therapy-response monitoring, and finally the first clinical application of the folate-PET tracer in RA patients with active disease. Consequently, folate-based PET tracers hold great promise for macrophage imaging in a variety of (chronic) inflammatory (autoimmune) diseases beyond RA.

So far, numerous molecules and biomolecules have been evaluated for tumor targeting purposes for radionuclide-based imaging and therapy modalities. Due to the high affinity and specificity against tumor antigens, monoclonal antibodies are appropriate candidates for tumor targeting. However, their large size prevents their comprehensive application in radionuclide-based tumor imaging or therapy, since it leads to their low tumor penetration, low blood clearance, and thus inappropriate tumor-to-background ratio. Nowadays, the variable domain of heavy-chain antibodies from the Camelidae family, known as nanobodies (Nbs), turn into exciting candidates for medical research. Considering several innate advantages of these new tumor-targeting agents, including excellent affinity and specificity toward antigen, high solubility, high stability, fast washout from blood, convenient production, ease of selection, and low immunogenicity, it assumes that they may overcome generic problems of monoclonal antibodies, their fragments, and other vectors used for tumor imaging/therapy. After three decades of Nbs discovery, the increasing number of their preclinical and clinical investigations, which have led to outstanding results, confirm their application for tumor targeting purposes. This review describes Nbs characteristics, the diagnostic and therapeutic application of their radioconjugates, and their recent advances.

Human epidermal growth factor receptor 2 (HER2) is overexpressed in several cancers. Today’s tumor targeting is receiving more attention due to its specificity to target receptor-dependent cancers. The aim of this study was to evaluate the 99mTc-HYNIC-(tricine)-(Ser)3-LTVPWY peptide for tumor targeting and imaging with overexpression of HER2. HYNIC-(Ser)3-LTVPWY peptide was labeled with 99mTc using tricine as a co-ligand at room temperature. Specific binding of this radiolabeled peptide was assessed on four cancer cell lines with different levels of HER2 receptor expression. Also the affinity of 99mTc-HYNIC-(tricine)-(Ser)3-LTVPWY peptide to the HER2 receptor was evaluated in the SKOV-3 cell line. Biodistribution study of this radiolabeled peptide was performed in SKOV-3 tumor bearing nude mice. The HYNIC conjugated peptide was simply labeled with 99mTc radionuclide with high labeling efficiency about 98±1% showing favorable stability in normal saline and human serum. In the presence of unlabeled peptide as competitor, the HER2 binding capacity of the radiolabeled peptide reduced (approximately five-fold). The KD and Bmax values were found 2.6±0.5 nM and (2.6±0.1)×106, respectively. The tumor/muscle ratios for this radiotracer were determined 1.17±0.77, 1.15±0.32 and 2.65±0.32 at 1, 2 and 4 h after injection, respectively. Presaturation of HER2 receptors in SKOV-3 xenografted nude mice showed a reduction in the tumor/muscle ratio confirming in vivo specificity of the peptide. According to SPECT imaging, the tumor was visualized in mouse after 4 h postinjection of radiolabeled peptide. 99mTc-HYNIC-(tricine)-(Ser)3-LTVPWY peptide exhibited overexpressed HER2 tumor targeting.

Overexpression of human epidermal receptor 2 (HER2) has given the opportunity for targeting and delivering of imaging radiotracers. The aim of this study was to evaluate the 99mTc-HYNIC-(EDDA/tricine)-(Ser)3-LTVSPWY peptide for tumor targeting and imaging of tumor with overexpression of HER2. The HYNIC-(Ser)3-LTVSPWY was labeled with 99mTc in presence of EDDA/tricine mixture as co-ligands. The in vitro and in vivo studies of this radiolabeled peptide were performed for cellular specific binding and tumor targeting. The high radiochemical purity of 99mTc-HYNIC (EDDA/tricine)-(Ser)3-LTVSPWY was obtained to be 99%. It exhibited high stability in normal saline and human serum. In HER2 binding affinity study, a significant reduction in uptake of radiolabeled peptide (7.7 fold) was observed by blocking SKOV-3 cells receptors with unlabeled peptide. The KD and Bmax values for this radiolabeled peptide were determined as 3.3 ± 1.0 nM and 2.9 ± 0.3 × 106 CPM/pMol, respectively. Biodistribution study revealed tumor to blood and tumor to muscle ratios about 6.9 and 4 respectively after 4 h. Tumor imaging by gamma camera demonstrated considerable high contrast tumor uptake. This developed 99mTc-HYNIC-(Ser)3-LTVSPWY peptide selectively targeted on HER2 tumor and exhibited a high target uptake combined with acceptable low background activity for tumor imaging in mice. The results of this study and its comparison with another study showed that 99mTc-HYNIC-(EDDA/tricine)-(Ser)3-LTVSPWY is much better than previously reported radiolabeled peptide as 99mTc-CSSS-LTVSPWY for HER2 overexpression tumor targeting and imaging.

This article is a Letter to the Editor and does not include an Abstract.

Overexpression of human epidermal receptor 2 (HER2) has given the opportunity for targeting and delivering of imaging radiotracers. The aim of this study was to evaluate the