W. Stephen Nichols

Antiglioma Immunological Memory in Response to Conditional Cytotoxic/Immune-Stimulatory Gene Therapy: Humoral and Cellular Immunity Lead to Tumor Regression

Purpose: Glioblastoma multiforme is a deadly primary brain cancer. Because the tumor kills due to recurrences, we tested the hypothesis that a new treatment would lead to immunological memory in a rat model of recurrent glioblastoma multiforme. Experimental Design: We developed a combined treatment using an adenovirus (Ad) expressing fms-like tyrosine kinase-3 ligand (Flt3L), which induces the infiltration of immune cells into the tumor microenvironment, and an Ad expressing herpes simplex virus-1–thymidine kinase (TK), which kills proliferating tumor cells in the presence of ganciclovir. Results: This treatment induced immunological memory that led to rejection of a second glioblastoma multiforme implanted in the contralateral hemisphere and of an extracranial glioblastoma multiforme implanted intradermally. Rechallenged long-term survivors exhibited anti-glioblastoma multiforme–specific T cells and displayed specific delayed-type hypersensitivity. Using depleting antibodies, we showed that rejection of the second tumor was dependent on CD8+ T cells. Circulating anti‐glioma antibodies were observed when glioblastoma multiforme cells were implanted intradermally in naïve rats or in long-term survivors. However, rats bearing intracranial glioblastoma multiforme only exhibited circulating antitumoral antibodies upon treatment with Ad-Flt3L + Ad-TK. This combined treatment induced tumor regression and release of the chromatin-binding protein high mobility group box 1 in two further intracranial glioblastoma multiforme models, that is, Fisher rats bearing intracranial 9L and F98 glioblastoma multiforme cells. Conclusions: Treatment with Ad-Flt3L + Ad-TK triggered systemic anti–glioblastoma multiforme cellular and humoral immune responses, and anti–glioblastoma multiforme immunological memory. Release of the chromatin-binding protein high mobility group box 1 could be used as a noninvasive biomarker of therapeutic efficacy for glioblastoma multiforme. The robust treatment efficacy lends further support to its implementation in a phase I clinical trial. (Clin Cancer Res 2009;15(19):6113–27)

Human papillomavirus genotypes in anal intraepithelial neoplasia and anal carcinoma as detected in tissue biopsies.

Human papillomavirus (HPV) infection strongly correlates with the development of anal intraepithelial neoplasias and carcinomas; however, few studies have characterized the distribution of the specific subtypes of the virus in the varying grades of dysplasia. This report characterizes the distribution of HPV 16/18 in surgical specimens with anal intraepithelial neoplasia (AIN) I–III and histological variants of anal carcinoma. A total of 111 anal surgical specimens with no dysplasia (10), AIN I–III (53), and anal carcinomas (48) were evaluated for the presence of high-risk HPV infection and subtyped by nested PCR or the Invader Assay. High-risk virus types were detected in progressively greater number of anal intraepithelial lesions from 56% in low grade to 88% in high grade. Type 16 was the prevalent subtype and was noted in 28% of low grade and 68% of high-grade lesions. Moderate dysplasias showed type 16 in 20%, a prevalence similar to that in low-grade lesions. The non-16/18 subtypes of the virus predominated and were present in 50% of the cases. Most (89%) squamous carcinomas were associated with high-risk viruses, 68% with type 16, a prevalence similar to that noted in high-grade dysplasia. Non-16/18 subtypes were encountered more frequently in squamous carcinomas from immunodeficient individuals (57% cases) as compared with immunocompetent individuals (18% cases). The similarity in the prevalence of type 16 in high-grade dysplasia and squamous carcinomas suggests that anal intraepithelial lesion III is the true precursor of squamous carcinoma and warrants aggressive management. Anal intraepithelial lesions II showed a virus distribution that was similar to low-grade dysplasia. In addition, a subset of these that were associated with type 16 or 18 showed progression, whereas those associated with non-16/18 subtypes regressed, thereby raising the possibility of conservative management for these lesions.

Human Papillomavirus (HPV) in Atypical Squamous Cervical Cytology: the Invader HPV Test as a New Screening Assay

ABSTRACT In surveillance for cervical neoplasia, a diagnosis of cytologically atypical squamous cells of undetermined significance (ASCUS) presents a significant clinical issue, often dependent on testing for high-risk (HR) human papillomavirus (HPV) for the triage of patients. HPV type 16 now appears to be a critical concern in the follow-up of patients with ASCUS. The Invader HPV (Inv2) test, by Third Wave Technologies, Inc., is a recently developed analyte-specific reagent assay that uses probe sets for the detection of 14 HR HPV subtypes. These probe sets are A5/A6 (HPV types 51, 56, and 66), A7 (HPV types 18, 39, 45, 59, and 68), and A9 (HPV types 16, 31, 33, 35, 52, and 58). This report describes the performance characteristics of the Inv2 test in the screening of ASCUS cervical cytology specimens and correlates the results of the Inv2 test with those of the Hybrid Capture II HPV (HC2) test by Digene. The linear array HPV genotyping test (Roche Molecular Systems) was used as a reference method for the testing of samples with discordant results. Ninety-four Pap smear samples with a cytological diagnosis of ASCUS and 39 samples with a negative diagnosis were tested. The results of the Inv2 test demonstrated a good (86.6%) concordance with those of the HC2 test, with an overall sensitivity and specificity of 96% for the Inv2 test. Additionally, the Inv2 assay, which offers high-throughput, semiautomated DNA extraction, allows the subgrouping of HPV types by differential probe sets, could provide a useful test for screening for HPV, and has the potential to provide an improved means of risk stratification and the selection of patients for further HPV subtyping.

Epstein-Barr virus infection in liver transplantation patients: correlation of histopathology and semiquantitative Epstein-Barr virus-DNA recovery using polymerase chain reaction.

Epstein-Barr virus (EBV) infection may complicate orthotopic liver transplantation, and can lead to hepatitis with subsequent graft failure and to benign and malignant lymphoproliferative disorders. Early diagnosis allows for prevention or treatment of complications. Histopathologic features of EBV infection in the liver vary and may be difficult to recognize. To delineate the morphologic features that allow for recognition we studied 61 biopsy specimens from 37 patients, correlating the results of EBV-DNA demonstration after polymerase chain reaction with histopathology of formalin-fixed, hematoxylin-eosin-stained liver biopsy specimens. DNA was extracted from fresh liver biopsy samples, and polymerase chain reaction was carried out with EBV primers (capsid protein gp220) using standard techniques and 25-cycle amplification. Epstein-Barr virus-related sequences after polymerase chain reaction were detected by DNA blot assay. Histopathologic features were classified into three categories on the basis of the semiobjective determination of the number and distribution of immunoblasts and other immature lymphocytes in portal tracts and sinusoids: highly suggestive (three biopsy specimens), indeterminant (one biopsy specimen), and negative (57 biopsy specimens). Only the three highly suggestive biopsy specimens had high levels of EBV-DNA. We conclude that the histopathologic features of EBV infection after orthotopic liver transplantation can be relied on to establish the diagnosis.

Screening of herbal extracts against multi-drug resistant Acinetobacter baumannii.

Antibiotic resistance is increasing resulting in a decreasing number of fully active antimicrobial agents available to treat infections with multi‐drug resistant (MDR) bacteria. Herbal medicines may offer alternative treatment options. A direct inoculation method simulating the standard disc diffusion assay was developed to determine in vitro antimicrobial activity of sixty herbal extracts against MDR‐Acinetobacter baumannii (A. baumannii). Eighteen herbal extracts inhibited MDR‐A. baumannii on agar plates, although the magnitude and quality of bacterial inhibition differed considerably among the antibacterial herbal extracts. Next, minimal inhibitory concentration (MIC) of these antibacterial herbal extracts was calculated using a broth microdilution assay. For most herbal extracts, the larger the zone of inhibition on agar plates, the lower the MIC. In general, hetero‐resistance on agar plates correlated with higher MIC. The skip well phenomenon was seen with two herbal extracts. In conclusion, 30% of the screened herbal extracts demonstrated in vitro antibacterial activity against MDR‐A. baumannii using similar rigorous testing methods as those commonly employed for assessing antimicrobial activity of synthetic antibacterial agents. Characterization of a specific compound conferring this antibacterial activity of the herbal extracts may help to identify novel antimicrobial agents active against highly resistant bacteria. Copyright

Invader human papillomavirus (HPV) type 16 and 18 assays as adjuncts to HPV screening of cervical papanicolaou smears with atypical squamous cells of undetermined significance.

High‐risk (HR) human papillomavirus (HPV) testing is standard practice for triaging women who have Papanicolaou (Pap) smears with atypical squamous cells of undetermined significance (ASC‐US), however, only 5% to 17% of these women have underlying cervical intraepithelial neoplasia 2 (CIN‐2)/CIN‐3. Recent reports have demonstrated that the presence of either HPV type 16 (HPV‐16) or HPV‐18 confers an elevated risk for CIN‐2/CIN‐3. The current study was designed to determine the prevalence of HPV‐16 and HPV‐18 in ASC‐US Pap smears and to determine whether further typing would enhance the risk stratification of patients for CIN‐2/CIN‐3.

In vitro activity of antibiotic combinations against multidrug‐resistant strains of Acinetobacter baumannii and the effects of their antibiotic resistance determinants

Various combinations of antibiotics are reported to show synergy in treating nosocomial infections with multidrug-resistant (MDR) Acinetobacter baumannii (A. baumannii). Here, we studied hospital-acquired outbreak strains of MDR A. baumannii to evaluate optimal combinations of antibiotics. One hundred and twenty-one strains were grouped into one major and one minor clonal group based on repetitive PCR amplification. Twenty representative strains were tested for antibiotic synergy using Etest(®). Five strains were further analyzed by analytical isoelectric focusing and PCR to identify β-lactamase genes or other antibiotic resistance determinants. Our investigation showed that the outbreak strains of MDR A. baumannii belonged to two dominant clones. A combination of colistin and doxycycline showed the best result, being additive or synergistic against 70% of tested strains. Antibiotic additivity was observed more frequently than synergy. Strains possessing the same clonality did not necessarily demonstrate the same response to antibiotic combinations in vitro. We conclude that the effect of antibiotic combinations on our outbreak strains of MDR A. baumannii seemed strain-specific. The bacterial response to antibiotic combinations is probably a result of complex interactions between multiple concomitant antibiotic resistance determinants in each strain.

Hepatitis C virus is not recoverable from liver tissue in cryptogenic cirrhosis: Failure to identify hepatitis C virus-RNA using reverse transcription-mediated polymerase chain reaction

Polymerase chain reaction (PCR) has been used to study liver biopsy tissue in patients with known or suspected hepatitis C virus (HCV). Recent studies of cryptogenic cirrhosis using PCR have been based on study of sera, and HCV has not been shown. The failure to show HCV in patients so studied has left unanswered the question of whether or not patients with cryptogenic cirrhosis could still harbor the virus in the liver. The authors studied liver tissue, obtained at the time of orthopic liver transplantation from 10 patients clinically diagnosed as having end-stage liver disease without demonstrable origin, so-called cryptogenic cirrhosis, using reverse transcription (RT)-PCR to try to recover HCV-RNA. Formalin-fixed, paraffin-embedded tissue was used. For comparison, the authors also studied similarly obtained samples from 10 patients with typical hepatitis C-associated cirrhosis and 10 patients with end-stage liver disease resulting from autoimmune hepatitis. The authors recovered HCV-RNA from 9 of 10 livers from patients with cirrhosis resulting from HCV, and 3 of 10 livers from patients with autoimmune hepatitis. HCV-RNA was not recovered from any of the livers of the 10 patients designated as having cryptogenic cirrhosis.

Deceiving high-grade cervical dysplasias identified as human papillomavirus non-16 and non-18 types by Invader human papillomavirus assays

High-grade cervical intraepithelial lesions (HGCINs) are easily diagnosed by established histologic criteria. However, we encountered problematic cases that are difficult to diagnose because features intermediate between dysplasia and metaplasia are present. p16 and Ki-67 immunostains proved HGCIN in these difficult and unusual cases. Because these are unusual cases of cervical dysplasia, we decided to type the human papillomavirus (HPV) using the Invader HPV test with analyte-specific reagents developed by Third Wave Technologies (Madison, WI, USA) (a new HPV screening assay applicable to tissue and amenable to rapid, sensitive, and specific detection of 14 high- to intermediate-risk HPV types) and a panel of immunostains. Results of these difficult cases are compared with classic HGCIN cases. We searched our pathology files over a period of 16 months for high-grade squamous intraepithelial lesion, cervical intraepithelial neoplasia II, cervical intraepithelial neoplasia III, and p16. To identify cases of difficult HGCIN with features intermediate between dysplasia and metaplasia, we reviewed all surgical cases of HGCIN that required p16 and Ki-67 diagnosis confirmation. Cases of interest were also stained with ProExC. Human papillomavirus screening and HPV 16/18 typing were performed by the Invader assays as described previously. Ten cases of classic HGCIN were easily diagnosed by hypercellularity, significant atypia, mitotic figures, and diffuse staining by p16, Ki67 and ProExC. The Invader assay identified HPV 16 (A9 positive/HPV16 positive) in 7 of 10 cases; the 3 others were A7 positive/not HPV18 (1) and A9 positive/not HPV16 (2). Eight cases of difficult HGCIN were identified. These showed only mild-to-moderate cellularity, a lack of significant atypia, absent-to-rare mitotic figures, and diffuse staining by p16, Ki-67, and ProExC. Human papillomavirus DNA was detected in 5 of 8 cases: only 1 was A9 positive/HPV16 positive, 1 was A5/A6 positive, 1 was A7 positive/not HPV18, and 2 were A9 positive/not HPV16. Three remaining cases demonstrated sufficient DNA to be analyzed by the Invader assay, but results were negative. This is a poorly recognized unusual group of cervical HGCIN with features intermediate between dysplasia and metaplasia that is easily confused by histologic examination. Immunostains prove the high-grade nature of these lesions, and Invader assay demonstrates association with HPV types other than 16/18 (ie, other HPV types detected by Invader assay). In this study, we present an unusual group of cases of high-grade dysplasia, not recognized by hematoxylin and eosin but identified by Ki67 and P16. It is very important to emphasize that this unusual group of high-grade dysplasias is associated with high-risk HPV but with types other than 16/18.

Hepatocarcinogenesis (Z#2)/mutagenesis during initiation stage

Previously, we developed a model for high incidence, endogenously generated hepatocellular carcinoma (HCC), the human alpha-1-antitrypsin (alpha1AT) Z gene transgenic mouse (Z#2). We now examine the potential utility of a model for endogenous carcinogenesis utilizing the Z#2 mouse also transgenic for the lacI gene, a convenient target for in vivo mutagenesis studies. We crossed the Z#2 line and mice transgenic for lambda/lacI shuttle vector (Big Blue), for determination of lacI mutant frequency during initiation of endogenous carcinogenesis. Five month old double transgenic mice (Z#2+/lacI+) successfully displayed: (1) the expected post-inflammatory stage of Z#2 carcinogenesis; and (2) hepatic lacI mutants measured at frequencies (10(-5)-10(-4)) useful to mutagenesis studies. In this study, hepatic lacI mutation frequencies in Z#2 transgenic mice appeared to be only slightly increased (< 2x) when compared to age matched negative controls. In the future, it may be important to reconcile possibly limited lacI mutagenesis at the time of initiation and demonstrated high incidence of hepatocarcinogenesis.