Commentary on "Prognostic effect of carcinoma in situ in muscle-invasive urothelial carcinoma patients receiving neoadjuvant chemotherapy."

BACKGROUND

Carcinoma in situ (CIS) is a poor prognostic finding in urothelial carcinoma. However, its significance in muscle-invasive urothelial carcinoma (MIUC) treated with neoadjuvant chemotherapy (NAC) is uncertain. We assessed the effect of CIS found in pretreatment transurethral resection of bladder tumor (TURBT) biopsies on the pathologic and clinical outcomes.

MATERIALS AND METHODS

Subjects with MIUC treated with NAC before cystectomy were identified. The pathologic complete response (pCR) rates stratified by TURBT CIS status were compared. The secondary analyses included tumor response, progression-free survival (PFS), overall survival (OS), and an exploratory post hoc analysis of patients with pathologic CIS only (pTisN0) at cystectomy.

RESULTS

A total of 137 patients with MIUC were identified. TURBT CIS was noted in 30.7% of the patients. The absence of TURBT CIS was associated with a significantly increased pCR rate (23.2% vs. 9.5%; odds ratio = 4.08; 95% CI: 1.19-13.98; P = 0.025). Stage pTisN0 disease was observed in 19.0% of the TURBT CIS patients. TURBT CIS status did not significantly affect the PFS or OS outcomes. Post hoc analysis of the pTisN0 patients revealed prolonged median PFS (104.5 vs. 139.9 months; P = 0.055) and OS (104.5 vs. 152.3 months; P = 0.091) outcomes similar to those for the pCR patients.

CONCLUSION

The absence of CIS on pretreatment TURBT in patients with MIUC undergoing NAC was associated with increased pCR rates, with no observed differences in PFS or OS. Isolated CIS at cystectomy was frequently observed, with lengthy PFS and OS durations similar to those for pCR patients. Further studies aimed at understanding the biology and clinical effect of CIS in MIUC are warranted.

Antitumor activity of Ad-IU2, a prostate-specific replication-competent adenovirus encoding the apoptosis inducer, TRAIL

In this study, we investigated the preclinical utility and antitumor efficacy of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) delivered by Ad-IU2, a prostate-specific replication-competent adenovirus (PSRCA), against androgen-independent prostate cancer. Through transcriptional control of adenoviral early genes E1a, E1b and E4, as well as TRAIL by two bidirectional prostate-specific enhancing sequences (PSES), expression of TRAIL as well adenoviral replication was limited to prostate-specific antigen (PSA) and prostate-specific membrane antigen (PSMA)-positive cells. Ad-IU2 induced 5-fold greater apoptosis selectively in PSA/PSMA-positive CWR22rv and C4-2 cells than an oncolytic adenoviral control. Furthermore, prolonged infection with Ad-IU2 reversed TRAIL resistance in LNCaP cells. Ad-IU2 exhibited superior killing efficiency in PSA/PSMA-positive prostate cancer cells at doses 5- to 8-fold lower than required by a PSRCA to produce a similar effect. This cytotoxic effect was not observed in non-prostatic cells, however. As an enhancement of its therapeutic efficacy, Ad-IU2 exerted a TRAIL-mediated bystander effect through direct cell-to-cell contact and soluble factors such as apoptotic bodies. In vivo, Ad-IU2 markedly suppressed the growth of subcutaneous androgen-independent CWR22rv xenografts compared to a PSRCA at six weeks post-treatment (3.1- vs. 17.1-fold growth of tumor). This study demonstrates the potential clinical utility of a PSRCA armed with an apoptosis-inducing ligand.

A conditionally replicative, Wnt/beta-catenin pathway-based adenovirus therapy for anaplastic thyroid cancer

Thyroid cancer affects between 10,000 and 15,000 people per year in the US. Typically, this disease can be controlled with surgical resection and radioiodide treatment. However, resistance to these conventional therapies is observed in some patients, who develop intractable anaplastic thyroid cancer (ATC), for which no effective therapies exist. Recently, a sizable fraction of undifferentiated or poorly differentiated thyroid cancers were shown to contain mutations in beta-catenin, an oncogenic protein involved in the etiology of cancers of many tissues. We developed a conditionally replicative adenovirus (named 'HILMI') which, by virtue of TCF response elements drives E1A and E1B expression, replicates specifically in cells with an active Wnt/beta-catenin pathway. We show that several thyroid cancer cell lines, derived from undifferentiated or anaplastic tissues and possessing an active Wnt/beta-catenin pathway, are susceptible to cell killing by HILMI. Furthermore, viral replication in ATC cells as xenograft tumors in nude mice was observed, and prolonged survival of mice with ATC tumors was observed following administration of the HILMI therapeutic vector. The results warrant further development of this therapeutic approach for ATC patients.

HOXB13 is downregulated in colorectal cancer to confer TCF4-mediated transactivation

Mutations in the Wnt signalling cascade are believed to cause aberrant proliferation of colorectal cells through T-cell factor-4 (TCF4) and its downstream growth-modulating factors. HOXB13 is exclusively expressed in prostate and colorectum. In prostate cancers, HOXB13 negatively regulates β-catenin/TCF4-mediated transactivation and subsequently inhibits cell growth. To study the role of HOXB13 in colorectal tumorigenesis, we evaluated the expression of HOXB13 in 53 colorectal tumours originated from the distal left colon to rectum with their matching normal tissues using quantitative RT–PCR analysis. Expression of HOXB13 is either lost or diminished in 26 out of 42 valid tumours (62%), while expression of TCF4 RNA is not correlated with HOXB13 expression. TCF4 promoter analysis showed that HOXB13 does not regulate TCF4 at the transcriptional level. However, HOXB13 downregulated the expression of TCF4 and its target gene, c-myc, at the protein level and consequently inhibited β-catenin/TCF-mediated signalling. Functionally, forced expression of HOXB13 drove colorectal cancer (CRC) cells into growth suppression. This is the first description of the downregulation of HOXB13 in CRC and its mechanism of action is mediated through the regulation of TCF4 protein stability. Our results suggest that loss of HOXB13 may be an important event for colorectal cell transformation, considering that over 90% of colorectal tumours retain mutations in the APC/β-catenin pathway.

Measuring coral reef decline through meta-analyses

Coral reef ecosystems are in decline worldwide, owing to a variety of anthropogenic and natural causes. One of the most obvious signals of reef degradation is a reduction in live coral cover. Past and current rates of loss of coral are known for many individual reefs; however, until recently, no large-scale estimate was available. In this paper, we show how meta-analysis can be used to integrate existing small-scale estimates of change in coral and macroalgal cover, derived from in situ surveys of reefs, to generate a robust assessment of long-term patterns of large-scale ecological change. Using a large dataset from Caribbean reefs, we examine the possible biases inherent in meta-analytical studies and the sensitivity of the method to patchiness in data availability. Despite the fact that our meta-analysis included studies that used a variety of sampling methods, the regional estimate of change in coral cover we obtained is similar to that generated by a standardized survey programme that was implemented in 1991 in the Caribbean. We argue that for habitat types that are regularly and reasonably well surveyed in the course of ecological or conservation research, meta-analysis offers a cost-effective and rapid method for generating robust estimates of past and current states.

Biochemical disease-free survival in patients with a high prostate-specific antigen level (20-100 ng/mL) and clinically localized prostate cancer after radical prostatectomy

OBJECTIVE

To examine our experience with radical prostatectomy (RP) in patients with a serum prostate-specific antigen (PSA) level of > 20 ng/mL (who are sometimes considered poor candidates for RP) to determine the outcome and possible predictors of a favourable outcome.

PATIENTS AND METHODS

We retrospectively reviewed the medical records of 79 patients who underwent RP with an initial PSA of 20-100 ng/mL. Biochemical disease-free survival (BDFS) was assessed using the Kaplan-Meier method and predictors of treatment outcome examined by uni- and multivariate analysis. Patients excluded from the analysis were 11 (14%) whose surgery was aborted after finding cancerous pelvic nodes and who did not undergo RP; four others with normal nodes during RP who had metastatic tumour on permanent sections; and 14 who had follow-up data for < 2 years.

RESULTS

The mean (sd) age of the 50 patients in the final study population was 63 (7) years and the mean PSA 37.9 (16.0) ng/mL. The median (range) follow-up was 54 (24-120) months. The BDFS was 60% at 3 years and 48% at 5 years of follow-up. Two patients developed a local recurrence and eight developed metastatic disease. On logistic regression analysis of factors influencing BDFS, only extracapsular extension of disease was predictive of PSA recurrence; no preoperative factor was significant. When time to PSA recurrence was assessed by Cox regression analysis, again only extracapsular extension was predictive, with no preoperative variable a statistically significant predictor.

CONCLUSIONS

Patients with a high serum PSA level (20-100 ng/mL) may be appropriate candidates for RP. While the cancer-free survival is not as good as in patients with a lower PSA, a significant percentage of patients achieve BDFS. No preoperative variables were predictive of disease-free survival or time to PSA recurrence.

Tissue-specific promoters in gene therapy for the treatment of prostate cancer

Delivery of therapeutic toxic genes to and their expression in tumor cells through the use of tissue-specific promoters could decrease their toxic effect on neighboring normal cells when virus-mediated gene delivery results in their infection. We have demonstrated the utility of two prostate cancer-specific promoters, long PSA and osteocalcin, for tissue-specific toxic gene therapy for prostate cancer. The two promoters were highly active in both androgen-dependent and androgen-independent prostate cancer cells. We also introduce the Phase I trial of osteocalcin promoter-based toxic gene therapy for bone metastases of prostate cancer, which is in progress at the University of Virginia.

Drug-resistant human bladder-cancer cells are more sensitive to adenovirus-mediated wild-type p53 gene therapy compared to drug-sensitive cells

We investigated the therapeutic potential and molecular mechanism of adenovirus-mediated wt p53 gene therapy for drug-resistant human bladder cancers. KK47, a human bladder-cancer cell line, along with the drug-resistant sublines KK47/DDP10, KK47/DDP20 (cisplatin-resistant) and KK47/ADM (doxorubicin-resistant) were used for the experiments. All 4 KK47 cell lines had genetically normal p53 genes. Using an in vitro cytotoxicity assay, the drug-resistant cell lines were more sensitive to Ad-CMV-p53 cell killing than the KK47 parental cell line. Ad-CMV-p53 induced higher levels of p53 protein and mRNA in the drug-resistant cell lines than in the parental cell line and, consequently, higher levels of p21 and Bax mRNA, which resulted in higher percentages of G(1) cell-cycle arrest and apoptosis. The higher efficiencies of adenoviral gene transfer in the drug-resistant cell lines were confirmed by X-gal staining after infection with Ad-CMV-beta-gal. In conclusion, adenovirus-mediated wt p53 gene therapy was more effective in the drug-resistant bladder-cancer cell lines than in the drug-sensitive bladder-cancer cell line.

A conditional replication-competent adenoviral vector, Ad-OC-E1a, to cotarget prostate cancer and bone stroma in an experimental model of androgen-independent prostate cancer bone metastasis

Prostate cancer has a high propensity to metastasize to bone, which often resists hormone, radiation, and chemotherapies. Because of the reciprocal nature of the prostate cancer and bone stroma interaction, we designed a cotargeting strategy using a conditional replication-competent adenovirus to target the growth of tumor cells and their associated osteoblasts. The recombinant Ad-OC-E1a was constructed using a noncollagenous bone matrix protein osteocalcin (OC) promoter to drive the viral early E1a gene with restricted replication in cells that express OC transcriptional activity. Unlike Ad-PSE-E1a, Ad-OC-E1a was highly efficient in inhibiting the growth of PSA-producing (LNCaP, C4-2, and ARCaP) and nonproducing (PC-3 and DU145) human prostate cancer cell lines. This virus was also found to effectively inhibit the growth of human osteoblasts and human prostate stromal cells in vitro. Athymic mice bearing s.c. androgen receptor-negative and PSA-negative PC-3 xenografts responded to a single intratumoral administration of 2 x 10(9) plaque-forming unit(s) of Ad-OC-E1a. In SCID/bg mice, intraosseous growth of androgen receptor-positive and PSA-producing C4-2 xenografts responded markedly to i.v. administrations of a single dose of Ad-OC-E1a. One hundred percent of the treated mice responded to this systemic Ad-OC-E1a therapy with a decline of serum PSA to an undetectable level, and 80% of the mice with PSA rebound responded to the second dose of systemic Ad-OC-E1a. Forty percent of the mice were found to be cured by systemic Ad-OC-E1a without subsequent PSA rebound or tumor cells found in the skeleton. This cotargeting strategy shows a broader spectrum and appears to be more effective than systemic Ad-PSE-E1a in preclinical models of human prostate cancer skeletal metastasis.

Serum-free recombinant production of adenovirus using a hollow fiber capillary system

A novel method for the production of adenoviral vectors on a scale sufficient to support most research applications and early phase clinical trials is presented. This method utilizes serum-free cell culture medium and a hollow fiber cell culture apparatus. Significantly less time and space are required than in conventional methods, and the resulting adenovirus is collected in a much smaller volume, simplifying the purification steps. The protocol described is a reproducible, convenient, biologically safe, and environmentally sound method for the production of adenoviral vectors for laboratory use and has the potential to scale-up the adenovirus production for clinical use.

p53 adenoviral vector (Ad-CMV-p53) induced prostatic growth inhibition of primary cultures of human prostate and an experimental rat model

BACKGROUND

Benign prostatic hyperplasia (BPH) is the most common proliferative disease affecting men. Numerous minimally invasive technologies are being developed or are currently in use to obviate the need for transurethral surgery. The goal of the present study was to develop a novel molecular based approach for the treatment of BPH using recombinant p53 adenoviral vector. The over-expression of wt-p53 can cause cell apoptosis or cell growth arrest, thus preventing the uncontrolled cell proliferation underlying BPH pathophysiology.

METHODS

Ad-CMV-p53, a replication-deficient recombinant adenovirus containing cytomegalovirus promoter driving p53 gene, was used. Human prostate stromal (PS) cells were evaluated for apoptosis (TUNEL assay), mRNA levels of key cell cycle regulators influencing apoptosis (p-53, Bax and Bcl-2) using quantitative RT-PCR and cytotoxicity after Ad-CMV-p53. Ad-CMV-p53 was unilaterally injected into rat ventral prostates and growth inhibition was measured by prostate weight 3 weeks after injection.

RESULTS

In vitro exposure to Ad-CMV-p53 significantly inhibited the proliferation of PS cells, induced mRNA over-expression of both wt-p53 and Bax, and increased the proportion of apoptotic cells. A 30% decrease in average prostate weight was demonstrated in rodents after Ad-CMV-p53 injection.

CONCLUSIONS

The results suggest that further investigation of molecular gene therapy with recombinant wt-p53 adenovirus for the treatment of BPH is warranted.

Surgical and postoperative factors affecting length of hospital stay after radical prostatectomy

BACKGROUND

Radical prostatectomy continues to comprise the mainstay of therapy for localized prostate carcinoma. However, caring for radical prostatectomy patients accounts for approximately half of the $1.7 billion annual cost of prostate carcinoma treatment. Length of stay (LOS) after surgery appears to be one of the main components of this cost. The first step in reducing cost is to identify those variables associated with LOS. Radical prostatectomy can be performed using two very different surgical techniques and with each technique different costs are incurred. The objective of the current study was to identify factors associated with LOS as a function of surgical approach. To reduce potential biases due to patient requests for longer hospitalization or physician preferences in that regard, secondary objectives were to identify factors associated with time to fluid intake (TTF) and time to consume solid foods (TTS).

METHODS

An institutional-based, retrospective chart review of 313 men with clinically localized prostate carcinoma who underwent either a perineal (RPP) or retropubic (RRP) prostatectomy at a single university center from March 1988 to October 1996 was undertaken. Information regarding LOS was available for 311 patients. Linear regression models were used to assess the association between covariables and LOS. Poisson regression models for count data were used to assess associations between covariables and the secondary endpoints of TTF and TTS. Covariables included: preoperative (age, race, prostate specific antigen, Gleason score, clinical stage, lymph node resection, comorbidity, and admission time), intraoperative (surgical approach, surgeon, operative time, estimated blood loss, transfusion requirement, anesthetic approach, and American Society of Anesthesiologists score), and postoperative (pain management complications and transfusions) parameters.

RESULTS

The median LOS was 4 days (range, 1-19 days) for RPP and 5 days (range, 3-16 days) for RRP approaches. The final model included six main effects and three interaction terms. Overall, LOS decreased over time with LOS decreasing at a faster rate in patients who underwent RPP. In general, patients who underwent RRP had an increased LOS compared with patients who underwent RPP. Complications from surgery and age increased the LOS for all patients; however, the increase was greater in patients who underwent RPP. In addition, the use of intraoperative epidural anesthesia and the increased use of postoperative narcotics were associated with increased LOS for patients undergoing both surgical approaches. TTF and TTS were significantly longer for patients who underwent the retropubic approach compared with those patients who underwent the perineal approach. After adjustment for surgical approach no other covariables were found to be associated with TTF. After adjustment for surgical approach, the occurrence of complications was found to be associated with TTS, indicating that patients who experienced complications took longer before they could tolerate solid foods.

CONCLUSIONS

In view of the importance of clinical care pathways in reducing medical expenditures from radical prostatectomy, the results of the current study may contribute to the further refining of these pathways by highlighting the differences and similarities among the variables affecting LOS as a function of surgical approach.

Osteocalcin-directed gene therapy for prostate-cancer bone metastasis

Osteocalcin (OC) is a major noncollagenous bone protein whose expression is limited almost exclusively to osteotropic tumors and mature calcified tissue (differentiated osteoblasts). The function of OC, a highly conserved gamma-carboxyglutamic acid-containing protein, relies in part on its ability to bind hydroxyapatite and act as a chemoattractant for bone-resorbing cells. Serum osteocalcin levels are used clinically as an index of active bone turnover. Research in our laboratory has revealed that OC is expressed in several solid tumors, including osteosarcoma and ovarian, lung, brain, and prostate cancers. Evidence arising from reverse-transcription polymerase chain reaction (RT-PCR; detection of OC mRNA), immunohistochemical staining (detection of OC protein), and transient transfection and reporter assay (detection of OC mRNA transcription) reveals that OC expression is up-regulated in numerous solid tumors, with its expression being further elevated in androgen-independent prostate cancers. A recombinant, replication-defective adenovirus, Ad-OC-TK (OC promoter-driven herpes-simplex-virus thymidine kinase) was constructed and, when combined with the appropriate prodrug, either ganciclovir (GCV) or acyclovir (ACV), was found to be effective at destroying prostate-cancer cell lines in vitro and prostate tumor xenografts in vivo in both subcutaneous and bone sites. Additionally, via use of the OC promoter the supporting bone stromal cells are cotargeted when the prostate cancer interdigitates with bone stroma at the metastatic skeletal sites. Thus, maximal tissue-specific cell toxicity is achieved by the interruption of cellular communication between the prostate cancer and the bone stroma. We describe herein the preclinical foundation as well as the design and implementation of an ongoing phase I clinical trial at the University of Virginia that targets androgen-independent metastatic prostate cancer using the Ad-OC-TK vector.

Cytotoxicity of adenoviral-mediated cytosine deaminase plus 5-fluorocytosine gene therapy is superior to thymidine kinase plus acyclovir in a human renal cell carcinoma model

PURPOSE

An estimated 11,600 Americans will die of renal cell carcinoma in 1998. The lack of effective chemotherapy or radiotherapy requires the investigation of novel treatment modalities. We compared two forms of toxic gene therapy, cytosine deaminase (CD) plus 5-fluorocytosine (5-FC) and thymidine kinase (TK) plus acyclovir (ACV), in pre-clinical models of human renal cell carcinoma.

MATERIALS AND METHODS

Replication-deficient recombinant adenoviral vectors containing the Rous sarcoma virus promoter driving CD (Ad-RSV-CD) or TK (Ad-RSV-TK) gene expression were constructed and tested for in vitro cell-killing assays at various viral multiplicity of infection (MOI) and in vivo for growth inhibition of a human renal cell carcinoma, SK-RC-29 models. Subcutaneous tumors of SK-RC-29 were examined by electron microscopy for presence of intercellular gap junctions. Levels of expression of the gap junctional associated connexin 43 protein in SK-RC-29, 31, 38, 42, 52 human RCC cell lines were examined by western immunoblotting.

RESULTS

In vitro cell-killing assay comparing Ad-RSV-CD/5F-C and Ad-RSV-TK/ACV at a wide range of MOI (2.5 to 20) revealed superior cell-kill by Ad-RSV-CD/5-FC over Ad-RSV-TK/ACV. Consistent with these results, we observed that Ad-RSV-CD/5-FC but not Ad-RSV-TK/ACV demonstrated a significant in vivo tumor growth inhibition. These results are corroborated by the lack of gap junctions in SK-RC-29 subcutaneous tumors by the electron microscopy and the absence of connexin-43 in all five human RCC cell lines by western immunoblotting.

CONCLUSION

We have demonstrated in this study that Ad-RSV-CD/5-FC is superior to Ad-RSV-TK/ACV for the treatment of human RCC in cell culture and animal models. The results are supported by the lack of gap junctional communication between RCC cells assessed by connexin-43 expression.

Diagnostic flexible peritoneoscopy: assessment of the contralateral internal inguinal ring during unilateral herniorrhaphy

BACKGROUND

Inguinal hernia is the most common pediatric surgical condition, with 75% of cases presenting unilaterally. No diagnostic study exists to determine preoperatively which children are at risk for subsequent contralateral hernia. The literature is not clear in advising whether surgeons should explore the contralateral side at the time of initial unilateral herniorrhaphy.

METHODS

Twenty-four patients presenting clinically with a unilateral hernia underwent flexible peritoneoscopy by isolation of the ipsilateral hernia sac and placement of a flexible cystoscope into the peritoneal cavity. After establishing a CO2 pneumoperitoneum, the contralateral side is checked for patency of the internal inguinal ring.

RESULTS

Our study found an open internal inguinal ring in 4 of 24 patients examined (16.7%). The other 20 patients were spared the usual routine contralateral exploration. An open contralateral internal inguinal ring was appreciated in two of nine (22.2%) left herniorrhaphy and 2 of 15 (13.3%) right herniorrhaphy patients. This technique requires an average of 4.5 minutes to perform. With 18-to 32-month follow-up, no hernias have developed on the contralateral side.

CONCLUSION

Diagnostic flexible peritoneoscopy is safe, quick, simple, and could be used to evaluate the contralateral internal inguinal ring in unilateral pediatric herniorrhaphy patients.

Flexible transinguinal laparoscopy to assess the contralateral ring in pediatric inguinal hernias

The incidence of contralateral patent processus vaginalis (CPPV) is >50% in infants with clinical unilateral inguinal hernia (CUIH) and decreases only slowly with advancing age. Laparoscopy through the hernia sac (transinguinal laparoscopy) to detect suspected CPPV is a safe and efficient way to minimize routine contralateral inguinal exploration, but can be technically difficult. We used flexible urologic instruments and/or angled cystoscopic lenses to make transinguinal laparoscopy easier. Over a 3-year period, 37 patients (34 boys and 3 girls) ranging in age from 4 months to 12 years (mean age 59 months) with CUIH underwent ipsilateral groin exploration and diagnostic transinguinal laparoscopy. Laparoscopy was performed with flexible 17F cystoscopes (26 cases), flexible 9F ureteroscopes (2 cases), and rigid 70 degrees cystoscope lenses (9 cases). We detected eight CPPV (22%) in our series of 20 right and 17 left inguinal hernias, in a mean transinguinal laparoscopy time of 4.5 minutes. At 26-month mean follow-up, no patient whose contralateral inguinal ring was deemed closed had developed a hernia. Flexible fiberoptic urologic scopes and/or angled cystoscope lenses make transinguinal laparoscopy easy and efficacious in the pediatric population. Our series represents the longest longitudinal study of transinguinal laparoscopy for the diagnosis of CPPV.

In vivo suppression of osteosarcoma pulmonary metastasis with intravenous osteocalcin promoter-based toxic gene therapy

Pulmonary metastases are the main cause of death of patients with several types of cancer, including osteosarcoma, renal cell carcinoma, malignant melanoma, and breast cancer. Previously, we demonstrated that intralesional injection of the recombinant adenovirus (Ad) vector containing the herpes simplex virus thymidine kinase (TK) gene driven by an osteocalcin (OC) promoter (Ad-OC-TK) effectively suppressed the growth of osteosarcoma cells in vitro and tumors in vivo in a tumor-specific manner when supplemented with the prodrug acyclovir (ACV). In this communication, we studied the potential efficacy of the treatment of osteosarcoma pulmonary metastases with a systemic delivery route of Ad-OC-TK supplemented with ACV. We established osteosarcoma lung metastases in nude mice by the intravenous injection of rat osteosarcoma cells, ROS 17/2.8. These cells colonized and formed tumor nodules within 1 week in the lungs of nude mice. Whereas systemic delivery of a recombinant Ad vector containing the Escherichia coli beta-galactosidase (beta-gal) gene driven by a Rous sarcoma virus universal promoter (Ad-RSV-beta-gal) resulted in the nonspecific expression of beta-gal activity in the lung parenchyma, Ad-OC-beta-gal administration resulted in specific beta-gal expression in tumor cells deposited in the lung. When nude mice bearing ROS 17/2.8 lung tumors were treated with systemic Ad-OC-TK through tail vein administration, subsequent intraperitoneal ACV treatment significantly decreased the number of tumor nodules (P < .0001) and the net lung wet weight (P = .0005) while significantly increasing (.005 < P < .01) the survival of animals, when compared with untreated and Ad-OC-TK- or ACV-treated control groups. These results suggest that Ad-OC-TK/ACV may be used as a systemic therapy for the treatment of osteosarcoma lung metastasis.

Development of prostate-specific antigen promoter-based gene therapy for androgen-independent human prostate cancer

PURPOSE

The goal of this study is to develop a tissue-specific toxic gene therapy utilizing the prostate specific antigen (PSA) promoter for both androgen-dependent (AD) and androgen-independent (AI) PSA-secreting prostate cancer cells. Ideally this gene therapy would be effective without the necessity of exposing the target cells to circulating androgens.

MATERIALS AND METHODS

An AI subline of LNCaP, an AD PSA-secreting human prostate cancer cell line, C4-2, was used in this study. Castrated mice bearing C4-2 tumors secrete PSA. A transient expression experiment was used to analyze the activity of two PSA promoters, a 5837 bp long PSA promoter and a 642 bp short PSA promoter, in C4-2 cells. A recombinant adenovirus (Ad-PSA-TK) carrying thymidine kinase under control of the long PSA promoter was generated. The tissue-specific activity of Ad-PSA-TK was tested in vitro and in vivo.

RESULTS

The long PSA promoter had superior activity over short PSA promoter, and higher activity in C4-2 cells than in LNCaP cells. High activity of Ad-PSA-TK was observed in C4-2 cells in an androgen deprived condition. In vitro, Ad-PSA-TK was further demonstrated to induce marked C4-2 cell-kill by acyclovir in medium containing 5% FBS. No cell-kill was observed in control WH cells (a human bladder cancer cell line). In vivo, Ad-PSA-P-TK with acyclovir significantly inhibited subcutaneous C4-2 tumor growth and PSA production in castrated animals.

CONCLUSION

The 5837 bp long PSA promoter was active in the androgen free environment and could be used to target both androgen-dependent and independent PSA-producing prostate cancer cells in vitro, and prostate tumors in castrated hosts.

Microfocal prostate cancer: biopsy cancer volume does not predict actual tumour volume

OBJECTIVE

To determine whether microfocal prostate cancer on needle biopsy predicts clinically insignificant disease in men undergoing radical prostatectomy.

PATIENTS AND METHODS

The records of 726 men who underwent radical prostatectomy between January 1990 and September 1995 were reviewed; 83 men had pre-operative prostatic needle biopsies which revealed microfocal prostate cancer. In these men, tumour volume (length) in the biopsy was compared to the percentage of tumour in the total prostatectomy specimen, and the pathological stage and clinical outcome reviewed.

RESULTS

Of the 83 men with microfocal prostate cancer on biopsy 75 (90%) had clinically significant disease. Pre-operative variables were of no use in identifying patients with clinically insignificant tumour volumes. When comparing those with microfocal tumour and those without at one institution, 69% had organ-confined (pT2) disease and 31% had capsular penetration (pT3), compared with 61% and 39%, respectively (P < 0.05). Additionally, the positive surgical margin rate for those with microfocal tumour was only 6%, compared with 26% for those without microfocal disease (P < 0.05). Biochemical failures during the median follow-up period of 24 months occurred in 6% of the men with microfocal cancer and in 15% of those undergoing total prostatectomy (P < 0.05).

CONCLUSIONS

Microfocal prostate cancer determined from the needle biopsy does not predict clinically insignificant disease.

Chemogene therapy: osteocalcin promoter-based suicide gene therapy in combination with methotrexate in a murine osteosarcoma model

We previously reported that the recombinant adenovirus (Ad) vector containing the thymidine kinase (TK) gene driven by the osteocalcin (OC) promoter (Ad-OC-TK), when delivered concurrently with acyclovir (ACV), is highly selective in blocking the growth of osteosarcoma in experimental models (Cancer Res. 1996;56:4614-4619). To investigate the possible additive effects of the combined treatment of gene therapy and conventional chemotherapy (chemogene therapy), we compared the effect of low dose (IC10) methotrexate (MTX) and OC promoter-based toxic gene therapy with either of these single modalities alone. We choose low dose MTX with the intent of determining whether chemosensitization of the osteosarcoma may be possible in combination with gene therapy with an overall reduced toxicity profile and enhanced therapeutic efficacy when compared to a single agent alone. In vitro, the combined treatments of MTX (3 ng/mL) and Ad-OC-TK (20 multiplicity of infection (MOI)/target cell) plus ACV (10 mg/mL) had an additive therapeutic effect over that of either MTX (P < 0.05) or Ad-OC-TK plus ACV treatment alone (P < 0.05). In vivo, nude mice with subcutaneous tumors of either human osteosarcoma (MG-63) or rat osteosarcoma (ROS) received three intratumoral injections of Ad-OC-TK (5 x 10(8) PFU) plus daily intraperitoneal ACV (40 mg/kg body weight) for 2 weeks in combination with five weekly bolus intraperitoneal MTX (87.5 mg/kg). Osteosarcoma tumor growth was inhibited more efficiently than by either Ad-OC-TK plus ACV (P < 0.05) or MTX treatment (P < 0.005) alone. At day 45 in the ROS group, 100% of the animals survived when treated with chemogene therapy, whereas 80% survived with gene therapy and no animals survived in the MTX-treated or untreated controls. In summary, we developed a novel therapeutic strategy for the treatment of osteosarcoma employing both chemotherapy and gene therapy. Chemogene therapy could potentially achieve better antitumor effects with reduced toxicity than the conventional chemotherapy or gene therapy protocols alone.

In vitro fertilization improves pregnancy rates for sperm obtained by rectal probe ejaculation

PURPOSE

We evaluated semen quality and pregnancy rates achieved with sperm obtained by rectal probe ejaculation.

MATERIALS AND METHODS

A series of 183 rectal probe ejaculation procedures performed by 1 of us (J. F. E.) on 40 anejaculatory men was reviewed.

RESULTS

Motile sperm were recovered from 95% of men undergoing rectal probe ejaculation. Live births were recorded for 15 of 33 couples (45%) via intrauterine insemination (10) or in vitro fertilization (5). Three of the latter 5 pregnancies were achieved with intracytoplasmic sperm injection.

CONCLUSIONS

Motile sperm are obtained from most men undergoing rectal probe ejaculation and pregnancy rates obtained with these sperm are improved by in vitro fertilization.

Proptosis as the initial presentation of fungal sinusitis in immunocompetent patients

BACKGROUND

Fungal sinusitis typically occurs in immunocompromised patients. The authors report four cases of fungal sinusitis in immunocompetent young adults, all of whom had proptosis.

METHODS

The diagnosis in all four patients was determined after orbital imaging and sinus biopsies.

RESULTS

All four patients required surgical removal of the fungal source and anti-fungal chemotherapy postoperatively.

CONCLUSION

Patients with proptosis, ocular pain, or other symptoms suggestive of orbital cellulitis unresponsive to antibiotic treatment should undergo radiographic imaging. If sinus disease is present, biopsy and culture may lead to the diagnosis of fungal disease. Surgical debridement and the appropriate systemic antifungal therapy usually lead to cure.

Volvulus of the ileal conduit: a late complication

We report 2 cases of ileal conduit volvulus presenting as a late complication. The importance of early diagnosis and surgical intervention is discussed.

Repair of the tarsoligamentous sling in New Zealand white rabbits using polytetrafluoroethylene graft material

Repair of large full-thickness lower lid defects requires reconstruction of the tarsoligamentous sling. This may necessitate either a tarsus sharing technique or a skin flap with a free cartilage graft. Obtaining tarsus or cartilage in these procedures has the disadvantage of requiring a second surgical site, which may cause further scarring and deformity. Polytetrafluoroethylene (PTFE) is a nonantigenic, inert, highly biocompatible, mechanically strong synthetic material that has been successfully utilized as a vascular and soft tissue patch since the 1970's. PTFE has been used in ophthalmic surgery to wrap orbital implants and as an interpositional graft for the correction of lower lid retraction. We evaluated the usefulness of PTFE in the reconstruction of the tarsoligamentous sling in 24 lids of 12 New Zealand white rabbits. PTFE with internodal spacings of 10 and 30 microns were used initially. Despite a lack of tissue inflammation, the PTFE grafts were uniformly extruded by 2 weeks postoperatively. Four additional lids were reconstructed using PTFE (30 and 60 microns) coated with a biological substrate. This graft material was also extruded. These results suggest that PTFE material may not be satisfactory for reconstruction of the tarsoligamentous sling.

Sixth nerve palsy as the initial presenting sign of metastatic prostate cancer. A case report and review of the literature

Cranial nerve palsies secondary to metastatic prostate cancer are uncommon occurrences. Usually appearing late in the course of the disease, they are associated with a poor prognosis. We report a case of a 71-year-old man who initially complained of diplopia and was found to have a right sixth nerve palsy and hyperdeviation caused by a mass in the clivus. Biopsy of the mass and extensive systemic workup revealed metastatic adenocarcinoma of the prostate gland.

Treatment of dysthyroid lower lid retraction with autogenous tarsus transplants

Lower lid retraction is commonly seen in dysthyroid orbitopathy. We have treated 55 lower lids in 38 patients with lower lid retraction by a tarsal transplant from the upper lid to the lower lid. An overall effect of 2-mm improvement +/- 0.7 mm occurred. Eighty-nine percent of the lids achieved the position of the lower lid within 1 mm of the limbus. We think that the upper to lower tarsal transplant offers a technically easy and reasonable solution to moderate lower lid retraction associated with dysthyroid orbitopathy.

Treatment of dysthyroid myopathy with adjustable suture recession

Extraocular muscle recessions with adjustable sutures were performed on 32 muscles for diplopia secondary to dysthyroid-myopathy. Orthophoria in the primary position was achieved in 30 of the 32 (94%) 1 day after surgery. All remained orthophoric for at least 6 weeks. Of 20 patients followed for 6 months or more, 12 (60%) remained orthophoric for the full extent of their follow-up (6 months to 8 years), and another three (15%) were asymptomatic with prisms (3, 4, and 8 prism diopters). Thus, a total of 15 of 20 (75%) patients remained asymptomatic at least 6 months after surgery.

Neuroimaging in neuro-ophthalmology

Computed tomographic scanning is an excellent modality for evaluation of most orbital and intracranial tumors and strokes. However, MR scanning is definitely superior to CT when evaluating for multiple sclerosis, posterior fossa lesions (evaluation of gaze palsies, internuclear ophthalmoplegia, and downbeat nystagmus), or when assessing an area where sagittal scanning is important (chiasmal lesions). Magnetic resonance has increased specificity when the CT is equivocal. Although MR and CT may be complementary in the information they provide, many clinical studies have shown MR to be superior to CT in evaluating cerebral infarctions, hematomas, the intracanalicular optic nerve, optic chiasm, sella turcica, and the cavernous sinus. Magnetic resonance generally has replaced metrizamide CT cisternography as the procedure of choice for evaluating the suprasellar cistern and posterior fossa. Computed tomography is still preferable for major trauma, especially involving acute fractures and hematomas, although MR is more sensitive to the more subtle intracerebral lesions, such as shear injuries and subdural hematomas, that may provide prognostic information. Computed tomography also is preferred in situations where detecting small amounts of calcification is important for the differential diagnosis. As the development of MR imaging continues with faster scan times, finer spatial resolution, the use of paramagnetic contrast agents, and with increased availability and decreased cost, MR imaging may become preferable to CT as the imaging modality of choice for the CNS and orbit.