Alterations in PIK3CA, the gene encoding the p110α subunit of phosphatidylinositol 3-kinase (PI3Kα), are frequent in head and neck squamous cell carcinomas. Inhibitors of PI3Kα show promising activity in various cancer types, but their use is curtailed by dose-limiting side effects such as hyperglycaemia. In the present study, we explore the efficacy, specificity and safety of the targeted delivery of BYL719, a PI3Kα inhibitor currently in clinical development in solid tumours. By encapsulating BYL719 into P-selectin-targeted nanoparticles, we achieve specific accumulation of BYL719 in the tumour milieu. This results in tumour growth inhibition and radiosensitization despite the use of a sevenfold lower dose of BYL719 compared with oral administration. Furthermore, the nanoparticles abrogate acute and chronic metabolic side effects normally observed after BYL719 treatment. These findings offer a novel strategy that could potentially enhance the efficacy of PI3Kα inhibitors while mitigating dose-limiting toxicity in patients with head and neck squamous cell carcinomas.
A major problem in the treatment of head and neck cancer today is the resistance of tumors to traditional radiation therapy, which results in 40% local failure, despite aggressive treatment. The main objective of this study was to develop a technique which will overcome tumor radioresistance by increasing the radiation absorbed in the tumor using cetuximab targeted gold nanoparticles (GNPs), in clinically relevant energies and radiation dosage. In addition, we have investigated the biological mechanisms underlying tumor shrinkage and the in vivo toxicity of GNP. The results showed that targeted GNP enhanced the radiation effect and had a significant impact on tumor growth (P < 0.001). The mechanism of radiation enhancement was found to be related to earlier and greater apoptosis (TUNEL assay), angiogenesis inhibition (by CD34 level) and diminished repair mechanism (PCNA staining). Additionally, GNPs have been proven to be safe as no evidence of toxicity has been observed.
Background: The use of thyroglobulin (Tg) and thyroglobulin antibodies (TgAb) for detecting disease recurrence is well validated following total thyroidectomy and radioiodine ablation. However, limited data are available for patients treated with thyroid lobectomy. Methods: Patients who had lobectomy for papillary thyroid cancer followed for >1 year, with sufficient data on Tg and TgAb, including subgroup analysis for Hashimoto’s thyroiditis and contralateral nodules. Results: One-hundred sixty-seven patients met the inclusion criteria. Average tumor size was 9.5 ± 6 mm. Following lobectomy, Tg was 12.1 ± 14.8 ng/mL. Of 52 patients with Hashimoto’s thyroiditis, 38% had positive TgAb with titers of 438 ± 528 IU/mL, and in patients without TgAb the mean Tg level was 14.7 ± 19.0 ng/mL. In 34 patients with contralateral nodules ≥1 cm, Tg was 15.3 ± 17 ng/mL. During the first 2 years of follow-up, Tg declined ≥1 ng/mL in 42% of patients (by 5.1 ± 3.7 ng/mL), remained stable in 22%, and increased in 36% (by 4.9 ± 5.7 ng/mL). During a mean follow-up of 6.5 years (78 ± 43.5 months), 18 patients had completion thyroidectomy and 12 were diagnosed with contralateral cancer (n = 8) or lymph node metastases (n = 4). In patients with recurrence followed for >2 years, there was a rise in Tg in 3 cases, Tg was stable in 2 cases, and in 1 TgAb decreased from 1534 to 276 IU/mL despite metastatic lymph nodes. Basal Tg and Tg dynamics did not predict disease recurrence. Conclusions: Serum thyroglobulin used independently is of limited value for predicting or detecting disease recurrence following thyroid lobectomy. Other potential roles of Tg, such as detecting distant metastases following lobectomy, should be further studied.