Characteristics of immunosuppressive regulatory T cells in cutaneous squamous cell carcinomas and role in metastasis

BACKGROUND

Non-melanoma skin cancer is the most common cancer worldwide, and cutaneous squamous cell carcinomas (SCCs) account for substantial morbidity and mortality because of their potential for metastasis. SCCs are surrounded by an immune cell infiltrate containing regulatory T cells (Tregs). The aim of this study was to characterise Tregs in SCCs and investigate whether increased Treg numbers in primary skin SCCs are associated with subsequent metastasis.

METHODS

Lymphocytes were extracted from freshly excised skin SCC tumours and corresponding peripheral blood and normal skin. Flow cytometry was used for T-cell analysis and cell sorting. Tritiated thymidine based lymphocyte proliferation assays and interferon γ (IFNγ) ELISPOT assays were used to assess peritumoral lymphocyte function in vitro. Immunohistochemistry was performed on primary cutaneous SCC sections from tumours that subsequently metastasised and from those that did not after 5-year follow-up.

FINDINGS

Increased frequencies of CD3+CD4+CD25hiCD127loFOXP3+ Tregs were found in SCCs (21·5% of CD4+ immune infiltrate, n=60 tumours) compared with corresponding peripheral blood (5·4%) and normal skin (7·6%). SCC Tregs expressed significantly higher levels of the co-stimulatory molecules OX40 (37·2% of FOXP3+ cell population, n=10 tumours) and 4-1BB (12·6%, n=9) than peritumoral non-regulatory T cells and Tregs from peripheral blood and normal skin (p=0·0005). The inhibitory receptor CTLA4 and the transcription factor Helios were expressed at high levels in peritumoral Tregs. SCC Tregs significantly suppressed phytohaemagglutinin-stimulated peritumoral CD4+ T-cell proliferation (p=0·005, n=10), peritumoral CD8+ T-cell proliferation (p=0·015, n=9), and IFNγ secretion by CD4+ effector T cells (p=0·026, n=10). Increased in-vitro proliferation of phytohaemagglutinin-stimulated peritumoral CD4+ T cells was shown after the addition of anti-OX40 antibodies (p=0·0078, n=9 tumours) and anti-4-1BB antibodies (p=0·0039, n=9). Immunohistochemistry showed fewer CD8+ T cells in SCCs that metastasised (n=29) than in non-metastatic SCCs (n=26) (28·5% of immune infiltrate vs 44·6%%, p<0·0001) and more FOX3+ Tregs (28·5% of immune infiltrate vs 49·3%, p<0·0001).

INTERPRETATION

Our study shows that immunosuppressive Tregs are present in the immune infiltrate of cutaneous SCCs, and contribute to ineffective anti-tumour immune responses, thereby permitting SCC development and promoting metastasis.

FUNDING

Wellcome Trust, National Institute for Health Research.

Unusual radiological behaviour after cryoablation of renal cell carcinoma

Cryoablation has evolved into an effective treatment option in patients with renal tumours. The procedure is minimally invasive, and patients are often spared the morbidity and hospital stay that is often associated with open or partial nephrectomy. We present an unusual case of a 62-year-old male patient who underwent cryoablation of a renal cell carcinoma. He subsequently developed apparent exuberant local disease progression, which spontaneously regressed on follow-up CT imaging.

Necrobiotic xanthogranuloma occurring in an eyelid scar

We present a case report of necrobiotic xanthogranuloma (NXG) in a 76-year-old Caucasian lady occurring as a nodule in a blepharoplasty scar. NXG is a rare histiocytic disease with progressive orbital and systemic features. Management options of excision biopsy or chemotherapy are discussed.

Characterization of a selective and potent antagonist of human P2X(7) receptors, AZ11645373

BACKGROUND AND PURPOSE

The ATP-gated P2X(7) receptor has been shown to play a role in several inflammatory processes, making it an attractive target for anti-inflammatory drug discovery. We have recently identified a novel set of cyclic imide compounds that inhibited P2X(7) receptor-mediated dye uptake in human macrophage THP-1 cells. In this study the actions and selectivity of one of these compounds, AZ11645373, were characterized.

EXPERIMENTAL APPROACH

We measured membrane currents, calcium influx, and YOPRO-1 uptake from HEK cells expressing individual P2X receptors, and YOPRO1 uptake and interleukin-1beta release from THP-1 cells in response to ATP and the ATP analogue benzoylbenzoyl ATP (BzATP).

KEY RESULTS

AZ11645373 up to 10 microM, had no agonist or antagonist actions on membrane currents due to P2X receptor activation at human P2X(1), rat P2X(2), human P2X(3), rat P2X(2/3), human P2X(4), or human P2X(5) receptors expressed in HEK cells. AZ11645373 inhibited human P2X(7) receptor responses in HEK cells in a non-surmountable manner with K (B) values ranging from 5 - 20 nM, with mean values not significantly different between assays. K (B) values were not altered by removing extracellular calcium and magnesium. ATP-evoked IL-1beta release from lipopolysaccharide-activated THP-1 cells was inhibited by AZ11645373, IC(50) = 90 nM. AZ11645373 was > 500-fold less effective at inhibiting rat P2X(7) receptor-mediated currents with less than 50% inhibition occurring at 10 microM.

CONCLUSIONS AND IMPLICATIONS

AZ11645373 is a highly selective and potent antagonist at human but not rat P2X(7) receptors and will have much practical value in studies of human cells.

A rare case of dysphagia: hypopharyngeal amyloidosis masquerading as a post-cricoid tumour

Amyloidoses are a group of disorders in which deposition of abnormal amounts of protein complexes (amyloid) occurs in a variety of tissues. The upper aerodigestive tract may be affected, particularly the larynx, but hypopharyngeal involvement is rarely reported. We present a unique case of amyloidosis of the post-cricoid region causing dysphagia. This case report highlights the need for otolaryngologists to consider the possibility of submucosal amyloid deposition, in the absence of mucosal lesions, in patients who present with dysphagia secondary to an obstructive lesion of the post cricoid region.

Monitoring unfractionated heparin therapy: relationship between eight anti-Xa assays and a protamine titration assay

Several studies have demonstrated that heparin assays, such as anti-activated factor X (anti-Xa) assays, can be successfully substituted for activated partial thromboplastin time for heparin dosage monitoring. A number of different assays are available and the relationship between results with different techniques is largely unknown. The aim of the present study was to assess the relationship between heparin assays by protamine titration and anti-Xa assays. Samples were collected from 43 patients receiving unfractionated heparin (UFH). In each sample, the heparin level was determined using a protamine titration assay and eight commercially available anti-Xa assays. The mean heparin level by protamine titration was 0.31 U/ml. Mean anti-Xa activity results ranged from 0.40 to 0.42 IU/ml for the three clotting-based assays, and from 0.32 to 0.40 IU/ml for five chromogenic assays. Thus mean results of different anti-Xa assays varied by up to 30%. The range of anti-Xa activity equivalent, on average, to 0.2-0.4 U/ml by protamine titration, considered to be the therapeutic range, was approximately 0.25-0.5 IU/ml, depending on the assay. The relationship between results of clotting and chromogenic methods was similar irrespective of whether or not warfarin-induced prolongation of international normalized ratios was present.

Detection of PCR products using self-probing amplicons and fluorescence

Molecular diagnostics is progressing from low-throughput, heterogeneous, mostly manual technologies to higher throughput, closed-tube, and automated methods. Fluorescence is the favored signaling technology for such assays, and a number of techniques rely on energy transfer between a fluorophore and a proximal quencher molecule. In these methods, dual-labeled probes hybridize to an amplicon and changes in the quenching of the fluorophore are detected. We describe a new technology that is simple to use, gives highly specific information, and avoids the major difficulties of the alternative methods. It uses a primer with an integral tail that is used to probe an extension product of the primer. The probing of a target sequence is thereby converted into a unimolecular event, which has substantial benefits in terms of kinetics, thermodynamics, assay design, and probe reliability.

Carney complex, Peutz-Jeghers syndrome, Cowden disease, and Bannayan-Zonana syndrome share cutaneous and endocrine manifestations, but not genetic loci

Carney complex (CC), Peutz-Jeghers syndrome (PJS), Cowden disease (CD), and Bannayan-Zonana syndrome (BZS) share clinical features, such as mucocutaneous lentigines and multiple tumors (thyroid, breast, ovarian, and testicular neoplasms), and autosomal dominant inheritance. A genetic locus has been identified for CC on chromosome 2 (2p16), and the genes for PJS, CD, and BZS were recently identified; genetic heterogeneity appears likely in both CC and PJS. The genes for PJS and CD/BZS, STK11/LKB1 and PTEN, respectively, may act as tumor suppressors, because loss of heterozygosity (LOH) of the PJS and CD/BZS loci has been demonstrated in tumors excised from patients with these disorders. We studied 2 families with CC in whom the disease could not be shown to segregate with polymorphic markers from the 2p16 locus. Their members presented with lesions frequently seen in PJS and the other lentiginosis syndromes. We also tested 16 tumors and cell lines established from patients with CC for LOH involving the PJS and CD/BZS loci. DNA was extracted from peripheral blood, tumor cell lines, and tissues and subjected to PCR amplification with primers from microsatellite sequences flanking the STK11/LKB1 and PTEN genes on 19p13 and 10q23, respectively, and a putative PJS locus on 19q13. All loci were excluded as candidates in both families with LOD scores less than 2 and/or by haplotype analysis. LOH for these loci was not present in any of the tumors that were histologically identical to those seen in PJS. The overall rate of LOH for the PJS and CD/BZS loci in tumors from patients with CC was less than 10%. We conclude that despite substantial clinical overlap among CC, PJS, CD, and BZS, LOH for the STK11 and PTEN loci is an infrequent event in CC-related tumors. Linkage analysis excluded the PJS and CD/BZS loci on chromosomes 19 (19p13 and 19q13) and 10 (10q23) from harboring the gene defect(s) responsible for the phenotype in these 2 families.

A homogeneous fluorescence assay for PCR amplicons: its application to real-time, single-tube genotyping

We have developed a method whereby a single TaqMan probe can be used for many PCR reactions. We demonstrate its application as an integrated system for the direct measurement of allele-specific amplicon generation coupled to the suppression of primer-dimer accumulation in PCR. The system uses a 5'-exonuclease assay of amplicon annealed fluorogenic probes that operates in conjunction with the Amplification Refractory Mutation System, whereby relative changes in reporter fluorescent emission are monitored in real-time using an analytical thermal cycler. We have called this system Three-STAR, and it is universal in that it can either use a single probe for the detection of any one target DNA sequence or a single pair of probes for genotyping any bi-allelic polymorphism. Three-STAR is, therefore, particularly useful for the single-tube genotype analysis of a variety of human DNA polymorphisms and mutations.

The elimination of primer-dimer accumulation in PCR

We attempted to produce primer-dimers (PDs) from a variety of primers with differing types and extents of complementarity. Where PDs were produced they were cloned and sequenced. We were unable to produce detectable PDs either with individual primers alone or with similar sequence primers even if they had 3'complementarity. These observations led to the hypothesis that a system could be developed whereby the accumulation of PDs in a PCR may be eliminated. We demonstrate a method for the general suppression of PD formation that uses a sequence of additional nucleotides (a Tail) at the 5' ends of amplimers. Tailed amplimers are present at low concentration and only participate during early cycles of PCR. In subsequent PCR cycles, amplification is achieved using a single primer that has the same sequence as that of the Tail portion of the early cycle primers, here we refer to this as a Tag. When products are small, as with PDs, there is a high local concentration of complementary sequences derived from the Tail. This favours the annealing of the complementary ends of a single strand produced by tailed primer interactions and gives rise to 'pan-handle' structures. The formation of these outcompetes the annealing of further Tag primers thereby preventing the accumulation of non-specific PD products. This aids the design of large multiplex reactions and provides a means of detecting specific amplicons directly in the reaction vessel by using an intercalating dye.

Myxo-papillary ependymoma: an unusual cause of a pelvic mass

One of the rarer causes of a pelvic mass is a myxo-papillary ependymoma. We describe the unusual presentation of a locally advanced tumour in an elderly lady.

Ultrasonic attenuation in fibroadenoma of the breast

Fifteen patients are described who attended out Breast Screening Programme, and were found to have sclerosed fibroadenomas, the imaging of which raised the possibility of carcinoma. In six of these a reflective zone between a mass lesion and distal acoustic shadowing might have been used to infer the benign diagnosis.

Technique and results of localization biopsy in a breast screening programme

The techniques of ultrasonographic and hookwire localization biopsy of impalpable breast lesions detected by a large breast screening unit during its first year of operation are described. Hookwire localization (HL) was performed using mammography. Ultrasonographic localization (UL) was used for lesions readily detectable by ultrasonography by marking the skin directly over the lesion and calculating its depth below the surface. UL is not appropriate when microcalcification is the sole mammographic abnormality. Localization was required for 150 of the 191 (78.5 per cent) screen-detected lesions. HL was used for 94 (62.7 per cent) and UL for 56 (37.3 per cent). Four lesions were missed by HL, none by UL; 35 per cent of lesions removed by HL and 39 per cent by UL were malignant, giving benign: malignant biopsy ratios of 1.8:1 and 1.5:1 respectively. Only 22 percent of the patients required overnight hospital stay. Localization biopsy plays a major role in the surgery for screen-detected lesions and, where applicable, UL is the technique of choice.

Nonseminomatous germ cell tumor with very high serum human chorionic gonadotropin

Most patients with disseminated nonseminomatous germ cell tumor (NSGCT) have an excellent prognosis with modern chemotherapy, although certain subgroups with a worse prognosis have been described. One such subgroup includes patients with high serum levels of the tumor marker, human chorionic gonadotropin (HCG). Sixteen patients of 104 treated for NSGCT at the CRC Wessex Medical Oncology Unit (Southampton, UK) presented with serum HCG greater than 25,000. Most of these patients exhibited features of the "choriocarcinoma syndrome" with bulky, rapidly progressive disease; frequent pulmonary, hepatic, and central nervous system complications; and a generally poorer response to standard NSGCT chemotherapy. Histologic identification of trophoblastic tumor was not made in all patients and is not essential for the diagnosis of the syndrome; indeed, closed biopsy may be contradicted in some circumstances because of the risk of hemorrhage. The NSGCT patients with poor prognosis, including patients with the choriocarcinoma syndrome, must be clearly identified in order to improve management and, eventually, cure rates.

Demonstration of oestrogen receptor in symptomatic breast carcinoma, using fine needle aspiration cytology

Oestrogen receptor immunocytochemical assay (ER-ICA) was used to determine oestrogen receptor (ER) content of cells in fine needle aspirate (FNA) specimens from 88 breast carcinomas. In 49 of these the radioligand binding assay for oestradiol was available for comparison. The predictive value of ER-ICA staining for a positive radioligand binding assay (greater than 10 fmol/mg protein) was 95%. Although the predictive value of negative staining was only 66%, 34 out of 37 ER-ICA negative tumours had radioligand binding assays below 60 fmol/mg protein. ER-ICA staining showed a strong positive correlation with age of the patient, positivity being rare before the menopause. There was a weak inverse correlation with tumour grade but none with tumour size or lymph node status. The assessment of ER by immunocytochemistry using FNA cytology is a rapid technique, which may easily be repeated and provides a pre-operative assessment of ER status. It allows confirmation that tumour cells are present in the sample and an assessment of tumour heterogeneity.