We herein compare the impact of the two methods on the bioavailability and localization of <sup>177</sup>Lu-DOTA-PEG<sub>4</sub>-[Nle<sup>14</sup>]BBN(7-14) analogs in GRPR-positive tumors in mice.
Yet by studying human tissues, we have recently shown that bombesin and its mammalian homologue gastrin-releasing peptide act as morphogens, promoting tumor differentiation when aberrantly upregulated in colon cancer.
The advantages of the RGD-BBN radiotracers over the corresponding BBN analogues are obvious for imaging MDA-MB-435 (GRPR(-)/integrin alpha(v)beta(3)(+)) tumor.
Interference with receptors for BN/GRP, LH-RH, or EGF might provide a therapeutic approach to inhibit tumor growth of androgen-independent prostate cancer.
All tumors expressed mRNA for subtype 1 bombesin/GRP receptor, but MiaPaCa-2, and in one experiment, SW-1990 tumors did not show binding sites for bombesin.
The bombesin-like peptides can function as autocrine growth factors in lung cancer and candidate tumor suppressor genes on chromosomes 3 and 9 play important roles in lung cancer.
The expression of GRP receptors was characterized at the mRNA level by reverse transcription-PCR, as well as at the protein level by binding of (125)I-[Tyr(4)] bombesin to membranes prepared from tumor tissue (K(d) 0.3 nM) and healthy kidney tissue from the same four patients.
Gastrin-releasing peptide is a neuropeptide linked to tumor aggressiveness, acting as an autocrine tumor growth factor by binding to its receptor, gastrin-releasing peptide receptor, expressed by many tumors.
Production of the growth factor gastrin-releasing peptide (GRP) or human bombesin has been shown to be a feature of neuroendocrine tumours of the lung, particularly small cell carcinoma, and is possibly responsible for the characteristically rapid growth of this tumour.
The bombesin (BN)-like peptides mediate a diverse spectrum of biological activities and have been implicated as autocrine growth factors in the pathogenesis and progression of some human small cell lung carcinoma tumors.
Radiolabeled GRPR-targeting analogs of bombesin (BN) have successfully been introduced as potential tracers for visualization and treatment of GRPR-overexpressing tumors.
Considering the potential importance of GRP as a tumor marker, we have conducted a retrospective immunohistochemical analysis of 176 lung tumors for markers of GRP gene expression, as well as several other markers of neuroendocrine cell differentiation: chromogranin A, neuron-specific enolase, and calcitonin.
The gastrin-releasing peptide (GRP) is a neuropeptide hormone and growth factor produced normally by neural and neuroendocrine cells, as well as by human small-cell lung cancer (SCLC) tumors and derived cell lines.
The GRPR, localized and expressed in extremely high density in a subgroup of vessels, may function as target for antiangiogenic tumor therapy or angiodestructive targeted radiotherapy with radiolabeled bombesin analogs alone, or preferably together with VEGFR targeted therapy.
Previous studies showed that antagonists of bombesin (BN)/gastrin-releasing peptide (GRP) inhibit the growth of various cancers by interfering with the growth-stimulatory effects of BN-like peptides and down-regulating epidermal growth factor receptors on tumors.
The circulating proGRP could serve as a valuable tumor marker for small-cell lung cancers, and the plasma level of proGRP is more stable compared with that of serum proGRP.
Immunohistochemically, the tumor was positive for the MIC2 gene product, whereas AE1/AE3, CAM5.2, and a variety of neuroendocrine markers such as chromogranin A, synaptophysin, and ProGRP, were negative.
In Vitro Mouse and Human Serum Stability of a Heterobivalent Dual-Target Probe That Has Strong Affinity to Gastrin-Releasing Peptide and Neuropeptide Y1 Receptors on Tumor Cells.