Advances in cellular therapy for the treatment of thyroid cancer

Targeting Cancer with Genetically Engineered TCR T Cells

The adoptive cell transfer (ACT) of genetically engineered T cell receptor (TCR) T cells is one of the burgeoning fields of immunotherapy, with promising results in current clinical trials. Presently, clinicaltrials.gov has over 200 active trials involving adoptive cell therapy. The ACT of genetically engineered T cells not only allows the ability to select for TCRs with desired properties such as high-affinity receptors and tumor reactivity but to further enhance those receptors allowing for better targeting and killing of cancer cells in patients. Moreover, the addition of genetic material, including cytokines and cytokine receptors, can increase the survival and persistence of the T cell allowing for complete and sustained remission of cancer targets. The potential for improvement in adoptive cell therapy is limitless, with genetic modifications targeting to improve weaknesses of ACT and to thus enhance receptor affinity and functional avidity of the genetically engineered T cells.

CITED1 promotes proliferation of papillary thyroid cancer cells via the regulation of p21 and p27

Background

It has been reported that CBP/p300-Interacting Transactivator with glutamic acid [E]/aspartic acid [D]-rich C-terminal domain 1 (CITED1) is overexpressed in papillary thyroid cancer (PTC). However, the functional significance and underlying mechanisms of CITED1 in PTC are largely unknown.

Methods

The Cancer Genome Atlas dataset and real-time PCR were used to determine the expression of CITED1 in PTC. The role of CITED1 in PTC cell proliferation was determined conducted using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), colony formation, 5-ethynyl-2'-deoxyuridine (EdU) incorporation, and flow cytometry assays in vitro, and a subcutaneous xenotransplantation tumor model in nude mice was established to analyze tumor growth in vivo. We studied the potential mechanisms underlying the contribution of CITED1 to PTC proliferation using western blotting and luciferase assays.

Results

We found that CITED1 was highly expressed in PTC. In vitro and in vivo experiments demonstrated that CITED1 was involved in PTC cell proliferation and tumorigenesis. Then, gain- and loss-of-function experiments revealed that CITED1 decreased the expression of p21 and p27, and thereby increased the phosphorylation of pRb as well as E2F1 transcriptional activity.

Conclusions

Our results suggest that CITED1 is overexpressed in PTC and that CITED1 promotes the proliferation of PTC cells via the regulation of p21 and p27, which indicates that CITED1 might be a potential therapeutic target in the treatment of PTC.

Punicalagin induces senescent growth arrest in human papillary thyroid carcinoma BCPAP cells via NF-κB signaling pathway

Papillary thyroid carcinoma (PTC) is the most common endocrine carcinoma. Our previous study revealed that punicalagin (PUN), an active component from pomegranate, triggered autophagic cell death and DNA damage response (DDR) in papillary thyroid carcinoma BCPAP cells. But the detailed anti-cancer mechanisms of punicalagin against PTC still remained to be further explored. DDR activation is a proven cause of cellular senescence, which mediates anti-tumor processes under certain circumstances. In this study, we reported that punicalagin treatment generated a senescent phenotype of BCPAP cells characterized as altered morphology, increased cell granularity and senescence-associated β-galactosidase (SA-β-Gal) staining. Senescence induced by punicalagin treatment was further confirmed by cell cycle arrest and upregulation of cyclin-dependent kinase inhibitor p21. Meanwhile, the senescence-associated secretory phenotype (SASP) included high levels of inflammatory cytokines, principally IL-6 and IL-1β. Furthermore, punicalagin exposure caused the phosphorylation and subsequent degradation of IκBα as well as the nuclear translocation of p65, suggesting the activation of NF-κB signaling pathway. Inhibition of NF-κB by pyrrolidine dithiocarbamate (PDTC), a selective inhibitor of NF-κB, partially reversed the cellular senescent phenotype induced by punicalagin in BCPAP cells as evidenced by the decreased fraction of SA-β-Gal staining positive cells and blockage of SASP generation. These results collectively showed that punicalagin treatment induced senescent growth arrest and SASP via triggering NF-κB activation. These observations elucidated novel anti-cancer mechanisms of punicalagin and might provide new potential prospects for PTC therapy.

Human anaplastic thyroid carcinoma cells are sensitive to NK cell-mediated lysis via ULBP2/5/6 and chemoattract NK cells

PURPOSE

Anaplastic thyroid carcinoma (ATC) is one of the most aggressive forms of cancer with no curative therapies available. To date, strategies to target ATC by immunotherapy have not been evaluated. We investigated whether ATC would be a suitable target for natural killer (NK) cell-based immunotherapy.

EXPERIMENTAL DESIGN

We first established seven new cell lines from ATC tumors, three from papillary thyroid carcinoma tumors and analyzed them together with eight additional ATC cell lines. Cells were analyzed for sensitivity to lysis by NK cells and their ability to chemoattract and regulate the activity of NK cells. In addition, fresh tumor samples and peripheral blood from six patients with ATC were analyzed for NK cell infiltration and phenotype.

RESULTS

We observed that ATC cell lines are sensitive to lysis by ex vivo expanded NK cells and that the lysis was abrogated upon blockade of NKG2D. Sensitivity of thyroid cancer cell lines to NK cell-mediated lysis correlated with surface expression of UL16-binding protein 2 on tumor cells. Moreover, ATC cell lines produced high levels of CXCL10 and stimulated migration of expanded NK cells and ATC tumors were enriched for NK cells expressing the cognate chemokine receptor CXCR3. However, compared with NK cells in peripheral blood, ATC tumor-derived NK cells displayed a suppressed phenotype with a downregulated expression of NKG2D. In vitro, suppression of NK cell-mediated lysis and NKG2D expression by ATC cells was restored upon neutralization of prostaglandin-E2.

CONCLUSIONS

ATC cell lines are sensitive to NK cell-mediated lysis via ULBP2/5/6 and chemoattract CXCR3-positive NK cells. Patients with ATC may benefit from NK cell-based immunotherapy.

Clinical and pathological implications of concurrent autoimmune thyroid disorders and papillary thyroid cancer

Cooccurrences of chronic lymphocytic thyroiditis (CLT) and thyroid cancer (DTC) have been repeatedly reported. Both CLT and DTC, mainly papillary thyroid carcinoma (PTC), share some epidemiological and molecular features. In fact, thyroid lymphocytic inflammatory reaction has been observed in association with PTC at variable frequency, although the precise relationship between the two diseases is still debated. It also remains a matter of debate whether the association with a CLT or even an autoimmune disorder could influence the prognosis of PTC. A better understanding about clinical implications of autoimmunity in concurrent thyroid cancer could raise new insights of thyroid cancer immunotherapy. In addition, elucidating the molecular mechanisms involved in autoimmune disease and concurrent cancer allowed us to identify new therapeutic strategies against thyroid cancer. The objective of this article was to review recent literature on the association of these disorders and its potential significance.