A simple, straightforward, and reproducible strategy for the construction of a near-infrared (NIR) fluorescence nanoprobe was developed by coating CuInS₂/ZnS quantum dots (CIS/ZnS QDs) with a novel amphiphilic bioconjugate. The amphiphilic bioconjugate with a tailor-designed structure of bovine serum albumin (BSA) as the hydrophilic segment and poly(ε-caprolactone) (PCL) as the hydrophobic part was fabricated by chemical coupling the hydrophobic polymer chain to BSA via the maleimide–sulfhydryl reaction. By incorporating CIS/ZnS QDs into the hydrophobic cores of the self-assembly of BSA-PCL conjugate, the constructed NIR fluorescence nanoprobe exhibited excellent fluorescent properties over a wide pH range (pH 3–10) and a good colloidal stability in PBS buffer (pH = 7.4) with or without 10% fetal bovine serum. The presence of the outer BSA shell effectively reduced the nonspecific cellular binding and imparted high biocompatibility and low-toxicity to the probe. Moreover, the NIR fluorescence nanoprobe could be functionalized by conjugating cyclic Arg-Gly-Asp (cRGD) peptide, and the decorated nanoprobe was shown to be highly selective for targeted integrin α_vβ₃-overexpressed tumor cell imaging. The feasibility of the constructed NIR fluorescence probe in vivo application was further investigated and the results demonstrated its great potential for in vivo imaging. This developed protocol for phase transfer of the CIS/ZnS QDs was universal and applicable to other nanoparticles stabilized with hydrophobic ligands.

Introduction Anti-epidermal growth factor receptor (EGFR)-targeted nanoparticles can be used to deliver a therapeutic and imaging agent to EGFR-overexpressing tumor cells. ¹³¹I-labeled anti-EGFR nanoparticles derived from cetuximab were used as a tumor-targeting vehicle in radionuclide therapy. Methods This paper describes the construction of the anti-EGFR nanoparticle EGFR–BSA–PCL. This nanoparticle was characterized for EGFR-targeted binding and cellular uptake in EGFR-overexpressing cancer cells by using flow cytometry and confocal microscopy. Anti-EGFR and non-targeted nanoparticles were labeled with ¹³¹I using the chloramine-T method. Analyses of cytotoxicity and targeted cell killing with ¹³¹I were performed using the MTT assay. The time-dependent cellular uptake of ¹³¹I-labeled anti-EGFR nanoparticles proved the slow-release effects of nanoparticles. A radioiodine therapy study was also performed in mice. Results The EGFR-targeted nanoparticle EGFR–BSA–PCL and the non-targeted nanoparticle BSA–PCL were constructed; the effective diameters were approximately 100 nm. The results from flow cytometry and confocal microscopy revealed significant uptake of EGFR–BSA–PCL in EGFR-overexpressing tumor cells. Compared with EGFR–BSA–PCL, BSA–PCL could also bind to cells, but tumor cell retention was minimal and weak. In MTT assays, the EGFR-targeted radioactive nanoparticle ¹³¹I–EGFR–BSA–PCL showed greater cytotoxicity and targeted cell killing than the non-targeted nanoparticle ¹³¹I–BSA–PCL. The radioiodine uptake of both ¹³¹I-labeled nanoparticles, ¹³¹I–EGFR–BSA–PCL and ¹³¹I–BSA–PCL, was rapid and reached maximal levels 4 h after incubation, but the ¹³¹I uptake of ¹³¹I–EGFR–BSA–PCL was higher than that of ¹³¹I–BSA–PCL. On day 15, the average tumor volumes of the ¹³¹I–EGFR–BSA–PCL and ¹³¹I–BSA–PCL groups showed a slow growth relationship compared with that of the control group. Conclusion The EGFR-targeted nanoparticle EGFR–BSA–PCL demonstrated superior cellular binding and uptake compared with those of the control BSA–PCL. The EGFR-targeted radioactive nanoparticle ¹³¹I–EGFR–BSA–PCL exhibited favorable intracellular retention of ¹³¹I. Radionuclide therapy using ¹³¹I–EGFR–BSA–PCL, which showed excellent targeted cell killing, suppressed cancer cell growth caused by EGFR overexpression.

A subset of thyroid cancers, recurrent differentiated thyroid cancers and anaplastic thyroid cancer (ATC), are difficult to treat by thyroidectomy and systemic therapy. A common mutation in thyroid cancer, BRAFV600E, has targetable treatment options; however, the results have been disappointing in thyroid cancers compared with BRAFV600E melanoma, as thyroid cancers quickly become resistant to BRAFV600E inhibitor (BRAFi). Here, we studied the molecular pathway that is induced in BRAFV600E thyroid cancer cells and patient-derived tumor samples in response to BRAFi, vemurafenib, using RNA-sequencing and molecular analysis. Both inducible response to BRAFi and acquired BRAFi resistance in BRAFV600E thyroid cancer cells showed significant activation of the JAK/STAT pathway. Functional analyses revealed that the combination of BRAFi and inhibitors of JAK/STAT pathway controlled BRAFV600E thyroid cancer cell growth. The Cancer Genome Atlas data analysis demonstrated that potent activation of the JAK/STAT signaling was associated with shorter recurrence rate in patients with differentiated thyroid cancer. Analysis of tumor RNA expression in patients with poorly differentiated thyroid cancer and ATC also support that enhanced activity of JAK/STAT signaling pathway is correlated with worse prognosis. Our study demonstrates that JAK/STAT pathway is activated as BRAFV600E thyroid cancer cells develop resistance to BRAFi and that this pathway is a potential target for anticancer activity and to overcome drug resistance that commonly develops to treatment with BRAFi in thyroid cancer. Implications: Dual inhibition of BRAF and JAK/STAT signaling pathway is a potential therapeutic treatment for anticancer activity and to overcome drug resistance to BRAFi in thyroid cancer.

OBJECTIVE. The aim of the present study is to investigate the biologic effects of internal irradiation and the therapeutic effectiveness of 131I-labeled arginine-glycine-aspartate (RGD)–bovine serum albumin (BSA)–polycaprolactone (PCL) (131I-RGD-BSA-PCL) in murine lung cancer models. MATERIALS AND METHODS. The target binding and cellular uptake of NCI-H460 lung cancer cells overexpressing integrin αvβ3 were observed by confocal microscopy. Flow cytometry was used to assay apoptosis. The biologic effects of internal irradiation and the therapeutic efficacy of 131I-RGD-BSA-PCL were investigated in murine lung cancer models; tumor size, body weight, histopathologic findings, and SPECT/CT imaging findings were also monitored. RESULTS. In vitro uptake studies performed using confocal microscopy showed that, after 1 hour of incubation with RGD-BSA-PCL or BSA-PCL, visible fluorescence was present in the cells, and after 8 hours, the florescent signal did not disappear. The mean (± SE) tumor uptake level (i.e., t...