A search for novel cancer/testis antigens in lung cancer identifies VCX/Y genes, expanding the repertoire of potential immunotherapeutic targets

Cancer/testis (CT) antigens are potential immunotherapeutic targets in cancer. However, the expression of particular antigens is limited to a subset of tumors of a given type. Thus, there is a need to identify antigens with complementary expression patterns for effective therapeutic intervention. In this study, we searched for genes that were distinctly expressed at a higher level in lung tumor tissue and the testes compared with other nontumor tissues and identified members of the VCX/Y gene family as novel CT antigens. VCX3A, a member of the VCX/Y gene family, was expressed at the protein level in approximately 20% of lung adenocarcinomas and 35% of squamous cell carcinomas, but not expressed in normal lung tissues. Among CT antigens with concordant mRNA and protein expression levels, four CT antigens, XAGE1, VCX, IL13RA2, and SYCE1, were expressed, alone or in combination, in about 80% of lung adenocarcinoma tumors. The CT antigen VCX/Y gene family broadens the spectrum of CT antigens expressed in lung adenocarcinomas for clinical applications.

Abstract B24: A systematic search for cancer/testis antigens in lung cancer identifies VCX/Y genes expanding the repertoire of potential immunotherapeutic targets

Background: A wide range of therapeutic cancer vaccines that target diverse tumor-associated antigens are currently been evaluated in early phase clinical trials. However the effectiveness of cancer vaccines is so far limited, potentially due in part to the limited availability of candidate targets with broad expression in a tumor type. Cancer/testis (CT) antigens are a major target of cancer vaccines, because CT antigens are specifically expressed in immune-privileged testis and placenta, and exhibit aberrant expression in various types of cancer, resulting in high immunogenicity with no self-tolerance and reduced adverse effects. However expression of particular antigens is limited to a subset of tumors of a given type. Thus there is a need to identify antigens with complementary expression patterns for more effective therapeutic intervention.

Methods: Gene expression data of BioGPS, and DNA methylation and RNA-seq data of TCGA lung cancer samples were downloaded. All lung cancer cell lines were cultured in RPMI1640 containing 10% FBS. A total of 83 pairs of treatment naive lung adenocarcinoma tissues and adjacent non-tumor lung tissues had been obtained earlier with informed consent. Gene expression data for cell lines and tissues were obtained using the Illumina Human WG-6 v3.0 Expression BeadChips. For mass spectrometric analysis, 38 non-small cell lung cancer (NSCLC) cell lines were cultured according to the standard SILAC protocol. The same batch of cells was used for analysis of whole cell extract, conditioned media and cell surface proteins. Tissue microarrays comprised 463 surgically resected NSCLC tumor specimens collected under an IRB protocol. Monoclonal anti-mouse VCX3A antibody was used for Western blot and immunohistochemistry analysis.

Results: With mining the public database BioGPS, we identified VCX/Y gene family as novel CT antigens in lung cancer. Our findings also suggested epigenetic regulation of VCX/Y gene expression, and potential oncogenic roles of VCX/Y genes. Expression of one of the VCX/Y family genes, VCX3A, was further confirmed at the protein level in ~20% of lung adenocarcinoma and ~35% of squamous cell carcinoma tumors. We further examined gene expression patterns of CT antigens to determine whether a panel could be assembled with broad representation in lung adenocarcinoma. Of 255 known CT antigens, 109 CT antigens were profiled at both mRNA and protein levels in 38 NSCLC cell lines. mRNA expression levels of 10 CT antigens were significantly and positively correlated with protein expression levels. We examined mRNA expression profiles of these 10 CT antigens, together with VCX and MAGEA3 which is a current target for vaccine immunotherapy, in 83 lung adenocarcinoma tumors. We selected XAGE1, VCX, IL13RA2, and SYCE1 to form a CT antigen panel and compared mRNA expression levels of these four genes between tumor and adjacent non-tumor tissue. One or more of the CT antigens in the panel were overexpressed in 66 (79.5%) of lung adenocarcinomas.

Conclusions: The present study identifies for the first time a novel CT antigen VCX/Y gene family in lung cancer. A CT antigen panel was found to provide a broad coverage of lung adenocarcinoma tumors tested, suggestive of a potential for more effective immunotherapy through targeting the combined antigen panel compared to a single antigen target.

Citation Format: Ayumu Taguchi, Allen D. Taylor, Jaime Rodriguez, Muge Celiktas, Hui Liu, Xiaotu Ma, Qing Zhang, Chee-Hong Wong, Alice Chin, Luc Girard, Carmen Behrens, Wan Lam, Stephen Lam, John D. Minna, Ignacio I. Wistuba, Adi F. Gazdar, Samir M. Hanash. A systematic search for cancer/testis antigens in lung cancer identifies VCX/Y genes expanding the repertoire of potential immunotherapeutic targets. [abstract]. In: Proceedings of the AACR-IASLC Joint Conference on Molecular Origins of Lung Cancer; 2014 Jan 6-9; San Diego, CA. Philadelphia (PA): AACR; Clin Cancer Res 2014;20(2Suppl):Abstract nr B24.

Early diagnosis of necrotizing fasciitis

BACKGROUND

Necrotizing fasciitis is a rapidly progressing skin infection characterized by necrosis of the fascia and subcutaneous tissue, accompanied by severe systemic toxicity. The objective of this systematic review was to identify clinical features and investigations that will aid early diagnosis.

METHODS

A systematic literature search of PubMed was undertaken using the keywords 'necrotising fasciitis', 'necrotising skin infection', 'diagnosis' and 'outcome'. Case series of 50 or more subjects with information on symptoms and signs at initial presentation, investigations and clinical outcome were included.

RESULTS

Nine case series were selected, with a total of 1463 patients. Diabetes mellitus was a co-morbidity in 44.5 per cent of patients. Contact with marine life or ingestion of seafood in patients with liver disease were risk factors in some parts of Asia. The top three early presenting clinical features were: swelling (80.8 per cent), pain (79.0 per cent) and erythema (70.7 per cent). These being non-specific features, initial misdiagnosis was common and occurred in almost three-quarters of patients. Clinical features that helped early diagnosis were: pain out of proportion to the physical findings; failure to improve despite broad-spectrum antibiotics; presence of bullae in the skin; and gas in the soft tissue on plain X-ray (although this occurred in only 24.8 per cent of patients).

CONCLUSION

A high index of suspicion of necrotizing fasciitis is needed in a patient presenting with cutaneous infection causing swelling, pain and erythema, with co-morbidity of diabetes or liver disease. The presence of bullae, or gas on plain X-ray can be diagnostic. Early surgical exploration is the best approach in the uncertain case.

A novel soluble form of Tim-3 associated with severe graft-versus-host disease

The T cell Ig and mucin domain 3 (Tim-3) receptor has been implicated as a negative regulator of adaptive immune responses. We have utilized a proteomic strategy to identify novel proteins associated with graft versus host disease (GVHD) after allogeneic hematopoietic cell transplantation (HCT). Mass spectrometry analysis of plasma from subjects with mid-gut and upper-gut GVHD compared with those without GVHD identified increased levels of a protein identified with high confidence as Tim-3. A follow-up validation study using an immunoassay to measure Tim-3 levels in individual plasma samples from 127 patients demonstrated significantly higher plasma Tim-3 concentrations in patients with the more severe mid-gut GVHD, compared with those with upper-gut GVHD (P = .005), patients without GVHD (P = .002), and normal controls (P < .0001). Surface expression of Tim-3 was increased on CD8(+) T cells from patients with grade 2 to 4 acute GVHD (P = .01). Mass spectrometry-based profiling of plasma from multiple subjects diagnosed with common diseases provided evidence for restricted release of soluble Tim-3 in the context of GVHD. These findings have mechanistic implications for the development of novel strategies for targeting the Tim-3 immune regulatory pathway as an approach to improving control of GVHD.

ST2 as a marker for risk of therapy-resistant graft-versus-host disease and death

BACKGROUND

No plasma biomarkers are associated with the response of acute graft-versus-host disease (GVHD) to therapy after allogeneic hematopoietic stem-cell transplantation.

METHODS

We compared 12 biomarkers in plasma obtained a median of 16 days after therapy initiation from 10 patients with a complete response by day 28 after therapy initiation and in plasma obtained from 10 patients with progressive GVHD during therapy. The lead biomarker, suppression of tumorigenicity 2 (ST2), was measured at the beginning of treatment for GVHD in plasma from 381 patients and during the first month after transplantation in three independent sets totaling 673 patients to determine the association of this biomarker with treatment-resistant GVHD and 6-month mortality after treatment or transplantation.

RESULTS

Of the 12 markers, ST2 had the most significant association with resistance to GVHD therapy and subsequent death without relapse. As compared with patients with low ST2 values at therapy initiation, patients with high ST2 values were 2.3 times as likely to have treatment-resistant GVHD (95% confidence interval [CI], 1.5 to 3.6) and 3.7 times as likely to die within 6 months after therapy (95% CI, 2.3 to 5.9). Patients with low ST2 values had lower mortality without relapse than patients with high ST2 values, regardless of the GVHD grade (11% vs. 31% among patients with grade I or II GVHD and 14% vs. 67% among patients with grade III or IV GVHD, P<0.001 for both comparisons). Plasma ST2 values at day 14 after transplantation were associated with 6-month mortality without relapse, regardless of the intensity of the conditioning regimen.

CONCLUSIONS

ST2 levels measured at the initiation of therapy for GVHD and during the first month after transplantation improved risk stratification for treatment-resistant GVHD and death without relapse after transplantation. (Funded by the National Institutes of Health.)

Abstract 1492: Systems analysis of epithelial-mesenchymal transition and cell invasion identifies functional gene signatures predictive of survival in lung cancer

We have implemented a systems approach to identify molecular features associated with mesenchymal or epithelial phenotypes and cell behavior in 38 lung adenocarcinoma cell lines that encompassed common known genomic alterations that drive the development of lung adenocarcinoma. Cell line characterization based on morphology, invasiveness, motility and cell-cell adhesion was integrated with proteomic, gene expression, microRNA and methylation profiles. Signatures were established from differential expression of transcripts and proteins in subsets of cell lines with mesenchymal and epithelial characteristics as well as high or low invasion and motility. The mesenchymal, invasion and migration signatures had common upregulation of genes or proteins related to cytoskeletal and actin-binding proteins. Sets of 148 and 74 transcripts corresponding to proteins that were overexpressed in mesenchymal cell lines and high invasive cell lines, respectively, were highly predictive of survival in three independent lung adenocarcinoma datasets. Subsets of 39 and 21 transcripts corresponding to cytoskeletal and acting binding proteins in the mesenchymal and invasive signatures were found to also predict survival in the three independent lung adenocarcinoma datasets, pointing to an association between cytoskeletal and actin binding proteins, a mesenchymal phenotype and tumor progression in lung adenocarcinoma.

Citation Format: Mark J. Schliekelman, Ayumu Taguchi, Jun Zhu, Xudong Dai, Qing Zhang, Alice Chin, Chee-Hong Wong, Hong Wang, Adi Gazdar, Ite Laird-Offringa, Muneesh Tewari, Jean Paul Thiery, Samir Hanash. Systems analysis of epithelial-mesenchymal transition and cell invasion identifies functional gene signatures predictive of survival in lung cancer. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 1492. doi:10.1158/1538-7445.AM2013-1492

Topological transport in spin-orbit coupled bosonic Mott insulators

We investigate topological transport in spin-orbit coupled bosonic Mott insulators. We show that interactions can lead to anomalous quasiparticle dynamics even when the spin-orbit coupling is Abelian. To illustrate the latter, we consider the spin-orbit coupling realized in the experiment of Lin et al. [Nature (London) 471, 83 (2011)]. For this spin-orbit coupling, we compute the quasiparticle dispersions and spectral weights, the interaction-induced momentum-space Berry curvature, and the momentum-space distribution of spin density, and propose experimental signatures. Furthermore, we find that, for a generic spin orbit coupling, in our approximation for the single-particle propagator, the ground state can in principle support an integer Hall conductivity if the sum of the Chern numbers of the hole bands is nonzero.

Spin caloritronics in noncondensed Bose gases

We consider coupled spin and heat transport in a two-component atomic Bose gas in the noncondensed state. We find that the transport coefficients show a temperature dependence reflecting the bosonic enhancement of scattering and discuss experimental signatures of the spin-heat coupling in spin accumulation, spin separation, and total dissipation. Close to the critical temperature for Bose-Einstein condensation, we find that the spin-heat coupling is strongly reduced, which is also reflected in the spin caloritronics figure of merit that determines the thermodynamic efficiency of spin-heat conversion.

SUICIDAL MERCURY INJECTION INTO THE UPPER LIMB: A CASE STUDY

We report a rare case of self-injection of mercury into the subcutaneous tissue of the upper limb. A multi-disciplinary management approach was adopted including cooperation between toxicologists, orthopaedic surgeons, radiologists and environment safety personnel. Surgical removal of mercury under radiological screening and systemic intoxication treated by chelating agents, namely dimercaprol and succimer. Serial serum and urine mercury levels showed an initial rise despite surgical removal and returned to normal after a prolonged period of time. Safety precautions were taken during surgery to avoid inadvertent intoxication of staff. Contamination of the operation theatre was monitored by the amount of mercury vapour released into the air. All personnels involved in the management of the patient did not show any evidence of mercury intoxication.

ULTRASOUND FOR THE DETECTION OF VEGETATIVE FOREIGN BODY IN HAND — A CASE REPORT

Foreign bodies in soft tissues are commonly encountered in daily orthopaedic practice. While most of the metals and glass foreign bodies can be detected by plain radiograph, organic substances such as wood and vegetative materials are radiolucent. Unfortunately, these radiolucent foreign bodies are usually more prone to cause an inflammatory reaction and infection. The detection can be even more difficult in cases of multiple foreign bodies and in penetrating injuries with small innocuous skin wounds. Ultrasonography is a sensitive and reliable investigation for detection of foreign bodies in soft tissue. We present a case of penetration injury to thumb with residual radiolucent foreign bodies and demonstrate the proper role of ultrasonography in the management of foreign bodies in soft tissues.

Targets of the tumor suppressor miR-200 in regulation of the epithelial-mesenchymal transition in cancer

The microRNA-200 (miR-200) family restricts epithelial-mesenchymal transition (EMT) and metastasis in tumor cell lines derived from mice that develop metastatic lung adenocarcinoma. To determine the mechanisms responsible for EMT and metastasis regulated by this microRNA, we conducted a global liquid chromatography/tandem mass spectrometry analysis to compare metastatic and nonmetastatic murine lung adenocarcinoma cells which had undergone EMT because of loss of miR-200. An analysis of syngeneic tumors generated by these cells identified multiple novel proteins linked to metastasis. In particular, the analysis of conditioned media, cell surface proteins, and whole-cell lysates from metastatic and nonmetastatic cells revealed large-scale modifications in the tumor microenvironment. Specific increases were documented in extracellular matrix (ECM) proteins, peptidases, and changes in distribution of cell adhesion proteins in the metastatic cell lines. Integrating proteomic data from three subproteomes, we defined constituents of a multilayer protein network that both regulated and mediated the effects of TGFβ. Lastly, we identified ECM proteins and peptidases that were directly regulated by miR-200. Taken together, our results reveal how expression of miR-200 alters the tumor microenvironment to inhibit the processes of EMT and metastasis.

Lung cancer signatures in plasma based on proteome profiling of mouse tumor models

We investigated the potential of in-depth quantitative proteomics to reveal plasma protein signatures that reflect lung tumor biology. We compared plasma protein profiles of four mouse models of lung cancer with profiles of models of pancreatic, ovarian, colon, prostate, and breast cancer and two models of inflammation. A protein signature for Titf1/Nkx2-1, a known lineage-survival oncogene in lung cancer, was found in plasmas of mouse models of lung adenocarcinoma. An EGFR signature was found in plasma of an EGFR mutant model, and a distinct plasma signature related to neuroendocrine development was uncovered in the small-cell lung cancer model. We demonstrate relevance to human lung cancer of the protein signatures identified on the basis of mouse models.

Tumor microenvironment-derived proteins dominate the plasma proteome response during breast cancer induction and progression

Tumor development relies upon essential contributions from the tumor microenvironment and host immune alterations. These contributions may inform the plasma proteome in a manner that could be exploited for cancer diagnosis and prognosis. In this study, we employed a systems biology approach to characterize the plasma proteome response in the inducible HER2/neu mouse model of breast cancer during tumor induction, progression, and regression. Mass spectrometry data derived from approximately 1.6 million spectra identified protein networks involved in wound healing, microenvironment, and metabolism that coordinately changed during tumor development. The observed alterations developed prior to cancer detection, increased progressively with tumor growth and reverted toward baseline with tumor regression. Gene expression and immunohistochemical analyses suggested that the cancer-associated plasma proteome was derived from transcriptional responses in the noncancerous host tissues as well as the developing tumor. The proteomic signature was distinct from a nonspecific response to inflammation. Overall, the developing tumor simultaneously engaged a number of innate physiologic processes, including wound repair, immune response, coagulation and complement cascades, tissue remodeling, and metabolic homeostasis that were all detectable in plasma. Our findings offer an integrated view of tumor development relevant to plasma-based strategies to detect and diagnose cancer.

Plasma proteome profiles associated with inflammation, angiogenesis, and cancer

Tumor development is accompanied by a complex host systemic response, which includes inflammatory and angiogenic reactions. Both tumor-derived and systemic response proteins are detected in plasma from cancer patients. However, given their non-specific nature, systemic response proteins can confound the detection or diagnosis of neoplasia. Here, we have applied an in-depth quantitative proteomic approach to analyze plasma protein changes in mouse models of subacute irritant-driven inflammation, autoreactive inflammation, and matrix associated angiogenesis and compared results to previously described findings from mouse models of polyoma middle T-driven breast cancer and Pdx1-Cre Kras(G12D) Ink4a/Arf (lox/lox)-induced pancreatic cancer. Among the confounding models, approximately 1/3 of all quantified plasma proteins exhibited a significant change in abundance compared to control mice. Of the proteins that changed in abundance, the majority were unique to each model. Altered proteins included those involved in acute phase response, inflammation, extracellular matrix remodeling, angiogenesis, and TGFβ signaling. Comparison of changes in plasma proteins between the confounder models and the two cancer models revealed proteins that were restricted to the cancer-bearing mice, reflecting the known biology of these tumors. This approach provides a basis for distinguishing between protein changes in plasma that are cancer-related and those that are part of a non-specific host response.

Detection of elevated plasma levels of epidermal growth factor receptor before breast cancer diagnosis among hormone therapy users

Applying advanced proteomic technologies to prospectively collected specimens from large studies is one means of identifying preclinical changes in plasma proteins that are potentially relevant to the early detection of diseases such as breast cancer. We conducted 14 independent quantitative proteomics experiments comparing pooled plasma samples collected from 420 estrogen receptor-positive (ER(+)) breast cancer patients ≤17 months before their diagnosis and matched controls. Based on the more than 3.4 million tandem mass spectra collected in the discovery set, 503 proteins were quantified, of which 57 differentiated cases from controls with a P value of <0.1. Seven of these proteins, for which quantitative ELISA assays were available, were assessed in an independent validation set. Of these candidates, epidermal growth factor receptor (EGFR) was validated as a predictor of breast cancer risk in an independent set of preclinical plasma samples for women overall [odds ratio (OR), 1.44; P = 0.0008] and particularly for current users of estrogen plus progestin (E + P) menopausal hormone therapy (OR, 2.49; P = 0.0001). Among current E + P users, the EGFR sensitivity for breast cancer risk was 31% with 90% specificity. Whereas the sensitivity and specificity of EGFR are insufficient for a clinically useful early detection biomarker, this study suggests that proteins that are elevated preclinically in women who go on to develop breast cancer can be discovered and validated using current proteomic technologies. Further studies are warranted to examine the role of EGFR and to discover and validate other proteins that could potentially be used for early detection of breast cancer.

Quantitative serum proteomics using dual stable isotope coding and nano LC-MS/MSMS

Stable isotope coding technique in combination with mass spectrometry has emerged as a powerful tool to accurately identify and differentially quantify proteins within complex protein mixtures. We present a novel methodology to increase the yield of quantified proteins while maintaining a high stable-isotopic labeling efficacy. With this approach, intact proteins in complex biological sample such as sera are labeled with the designated dual stable isotope coding (DSIC) systems. In brief, intact proteins are coded sequentially with acrylamide to label Cysteine residues (Cys) and with succinic anhydride to label Lysine residues (Lys). Protein samples coded with this dual stable isotope are subjected to an online 2D-HPLC fractionation. The resolved protein fractions are individually digested with trypsin and analyzed with nano LC-MS/MSMS. Our results show that the DSIC labeling efficiency is 100% for Cysteine (Cys) labeled with acrylamide and 98% for Lysine (Lys) labeled with succinic anhydride. A comparative analysis of DSIC labeling and single labeling of Cysteine residues was made. Analysis of an entire anion-exchange chromatography subfraction of sera yielded 165 identified proteins (criteria: error rate <5% and unique peptides >or=2), 104 of which were quantified using the single labeling method (i.e., Cysteine acrylamide labeling only). In contrast, using same criteria for identification, a total 185 proteins were identified and 174 proteins were quantified using the DSIC labeling technique.

Novel breast cancer metastasis-associated proteins

With the use of the breast cancer metastatic model, which comprises four isogenic cell lines, iTRAQ-based ESI-LC/MS/MS proteomics was employed to catalog protein expression changes as cancer cells acquire increasing metastatic potential. From more than 1000 proteins detected, 197 proteins, including drug-targetable kinases, phosphatases, proteases and transcription factors, displayed differential expression when cancer cells becomes more metastatic. Overall, the number of protein expression changes was evenly distributed across mildly ( approximately 30%), moderately ( approximately 40%) and aggressively ( approximately 30%) metastatic cancer cells. Some changes were found to be specific to one while others were required for two or more phenotypes. KEGG Orthology suggests major reprogramming in cell metabolism and to smaller extents in genetic and environmental information processing. Ten novel metastasis-associated proteins were identified and the iTRAQ-based expression profiles of 7 proteins were verified to be congruent with antibody-based methods. With the use of tissue microarrays comprising 50 matched cases of invasive and metastatic lesions, the expression profiles of SH3GLB1 and SUB1, SND1, TRIM28 were validated to be down- and up-regulated, respectively, during clinical progression of carcinoma in situ to invasive and metastatic carcinomas. Our study has unraveled proteome-wide molecular aberrations and potentially new players in breast cancer metastasis.

Phosphoproteomics, oncogenic signaling and cancer research

The past 5 years have seen an explosion of phosphoproteomics methods development. In this review, using epidermal growth-factor signaling as a model, we will discuss how phosphoproteomics, along with bioinformatics and computational modeling, have impacted key aspects of oncogenic signaling such as in the temporal fine mapping of phosphorylation events, and the identification of novel tyrosine kinase substrates and phosphorylation sites. We submit that the next decade will see considerable exploitation of phosphoproteomics in cancer research. Such a phenomenon is already happening as exemplified by its use in promoting the understanding of the molecular etiology of cancer and target-directed therapeutics.

Piriformis pyomyositis: a report of three cases

Pyomyositis is a subacute infection of skeletal muscles. It can be life-threatening if diagnosis and treatment are delayed. Only 5 cases of isolated piriformis pyomyositis have been reported. We report signs and symptoms of piriformis pyomyositis in 3 women who were treated mainly with antibiotics. Computed tomography is useful in making the diagnosis. Early diagnosis and treatment may avoid surgical treatment and reduce mortality.

Targeted quantitative analysis of Streptococcus pyogenes virulence factors by multiple reaction monitoring

In many studies, particularly in the field of systems biology, it is essential that identical protein sets are precisely quantified in multiple samples such as those representing differentially perturbed cell states. The high degree of reproducibility required for such experiments has not been achieved by classical mass spectrometry-based proteomics methods. In this study we describe the implementation of a targeted quantitative approach by which predetermined protein sets are first identified and subsequently quantified at high sensitivity reliably in multiple samples. This approach consists of three steps. First, the proteome is extensively mapped out by multidimensional fractionation and tandem mass spectrometry, and the data generated are assembled in the PeptideAtlas database. Second, based on this proteome map, peptides uniquely identifying the proteins of interest, proteotypic peptides, are selected, and multiple reaction monitoring (MRM) transitions are established and validated by MS2 spectrum acquisition. This process of peptide selection, transition selection, and validation is supported by a suite of software tools, TIQAM (Targeted Identification for Quantitative Analysis by MRM), described in this study. Third, the selected target protein set is quantified in multiple samples by MRM. Applying this approach we were able to reliably quantify low abundance virulence factors from cultures of the human pathogen Streptococcus pyogenes exposed to increasing amounts of plasma. The resulting quantitative protein patterns enabled us to clearly define the subset of virulence proteins that is regulated upon plasma exposure.

Tumour seeding following percutaneous needle biopsy of hepatocellular carcinoma

We report a hepatocellular carcinoma seeding following needle biopsy in a 57-year-old man who first presented with a focal hepatic lesion at another hospital. The patient had been a hepatitis B carrier for 20 years. Initial surveillance ultrasonography showed a lesion in segment IV, in the background of non-cirrhotic liver and normal serum alpha-foetoprotein level (8 ng/ml). A percutaneous needle biopsy was done and histopathology confirmed well-differentiated hepatocellular carcinoma. The patient had refused surgery and preferred to try traditional medicine. He presented to us four months after the initial biopsy with epigastric swelling. This was found to be due to a tumour seeding along the previous biopsy tract. He was given radiofrequency ablation (RFA) of tumour along the needle tract, in addition to the primary tumour. We conclude that the need for percutaneous needle biopsy should be critically evaluated in patients presenting with focal hepatic lesions and the role of RFA in treating tumour seeding needs further evaluation.