Circulating tumor cells (CTC) in patients with metastatic castration-resistant prostate cancer (CRPC) receiving abiraterone acetate (AA) after failure of docetaxel-based chemotherapy

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Background: Selecting targeted therapies and assessing outcome in patients (pts) with CRPC are significant unmet medical needs. A proportion of CRPC remain dependent on androgen receptor (AR) activation. AA inhibits CYP17 to decrease serum androgen to undetectable levels. Methods: AA (1000 mg QD oral) was studied in pts with metastatic CRPC who had progressed on docetaxel based chemotherapy. The primary endpoint was a >50% decline in PSA from baseline. We monitored changes in CTC number with therapy, and performed FISH for AR in CTC as previously described. Results: At MSKCC, 54 pts were screened and 48 treated; 38 pts received prednisone from the start of treatment. The median (IQR) age was 70 yrs (63–79), PSA 99.9 ng/mL (36.4–343), and CTC were 17 (4–49) per 7.5 ml of blood at baseline. Prior systemic therapy included > 3 hormonal therapies in 63%; while 71% received 1, 29% had 2 lines of chemotherapy. Metastatic sites were bone alone in 10 pts (21%), bone and lymph nodes in 21 (44%), 15 (31%) with visceral disease, 2 with soft tissue alone. Baseline CTC count was > 5 in 35 pts, whereas 13 pts had <5; CTC changes with treatment are presented in table below. Pts in Group A were treated on protocol for a median of 8.9 m, compared to 2.8 m in group B (P <0.001). Among pts with baseline CTC > 5, the CTC decline to <5 was associated with a decline in PSA by >50% (p< 0.001). From 28 pts with FISH in CTC, 13 (47%) pts had AR amplification, 8 (29%) pts had copy number gain, and 5 (10%) pts had no evident AR copy number abnormalities; FISH failed in 2 pts. PSA declined > 50% in 5 (38%) pts with AR amplification, 2 (25%) pts with gain, and 4 (80%) pts without AR abnormalities. Conclusions: Changes in CTC with treatment may represent valuable intermediary endpoints for clinical benefit. We are prospectively testing pre and post-therapy CTC, and separately AR FISH profiles and clinical outcomes in COU-AA-301, a phase III trial for CRPC patients who have received docetaxel based chemotherapy.

[Table: see text]

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Antitumor activity of MDV3100 in a phase I/II study of castration-resistant prostate cancer (CRPC)

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Background: MDV3100 is a novel AR antagonist selected for activity in prostate cancer model systems with overexpressed AR. In contrast to bicalutamide, MDV3100 blocks nuclear translocation of AR and DNA binding, and has no known agonist activity when AR is overexpressed. Antitumor activity of MDV3100 in a Phase I/II trial was assessed by prostate-specific antigen (PSA), soft tissue and osseous disease, circulating tumor cells (CTC), and time on treatment. Methods: Patients (pts) with progressive CRPC were enrolled in sequential cohorts of 3–6 pts at 30, 60, 150, 240, 360, 480 and 600 mg/day. Once the safety of a dose was established, enrollment was expanded at doses >60 mg/day to include 12 chemotherapy-naïve (naïve) and 12 post-chemotherapy pts per cohort. Results: 140 pts were enrolled. 114 pts at 30–360 mg/day have been followed for >12 weeks. PSA declines (>50% from baseline) were observed at week 12 in 57% (37/65) of naïve and 45% (22/49) of post-chemo pts. Data suggest a dose-response trend particularly in post-chemo pts where PSA responses were 32% at 60 and 150 mg/day and 58% at 240 and 360 mg/day. At 12 weeks, radiographic control (no progression) was observed in 35/47 pts (74%) with evaluable soft tissue lesions per PCWG2 guidelines and 50/81 pts (62%) with bone lesions. CTC counts on 101 of 114 pts showed 92% (56/61) with favorable (<5) counts pretreatment maintained favorable posttreatment counts, while 53% (21/40) converted from unfavorable to favorable posttreatment. For post-chemo pts, favorable retention was 100% (17/17) and unfavorable to favorable conversion at 240 and 360 mg/day was 60% (6/10). 87 pts at 30–240 mg/day have been followed for >24 weeks; 35 (40%) received treatment >24 weeks. At 600 mg/day, 2 of 3 pts had dose limiting toxicity (rash; seizure). Dose reductions due to fatigue were noted at 480 and 360 mg/day. Conclusions: MDV3100 is a promising candidate for the treatment of prostate cancer assessed by PSA, imaging, CTC, and time on treatment. The data suggest a dose-response trend and consistency across endpoints. Pt follow-up is continuing. The efficacy comparable to that at higher doses and the better adverse event profile, led to the selection of 240 mg/day as the recommended dose for a phase III trial in CRPC.

[Table: see text]

Bacopa monniera ameliorates amnesic effects of diazepam qualifying behavioral-molecular partitioning

Benzodiazepines are known to produce amnesia by involvement of GABAergic system and by interference of long term potentiation (LTP). In this study, we examined effect of Bacopa monniera on downstream molecules of LTP after diazepam-induced amnesia in mice. We used a Morris water maze scale for evaluating the effect of Bacopa monniera after screening for muscle coordination by rota rod. The index of acquisition and retrieval was recorded as escape latency time (ELT). Behavioral results showed that Bacopa monniera (120 mg kg(-1) oral) significantly reversed diazepam- (1.75 mg kg(-1) i.p.) induced amnesia in Morris water maze task. The molecular studies revealed that diazepam upregulated mitogen activated protein kinase (MAP kinase), phosphorylated CREB (pCREB) and inducible nitric oxide synthase (iNOS), while it downregulated nitrite, nitrate, total nitrite, cAMP response element binding protein (CREB) expression, phosphodiesterase, cyclic adenosine monophosphate (cAMP) without affecting calmodulin levels. Bacopa monniera suppressed the diazepam induced upregulation of MAP kinase, pCREB and iNOS and attenuated the downregulation of nitrite. It did not affect the cAMP, PDE, nitrate, total nitrite, total CREB level. These behavioral findings displayed the reversal of diazepam-induced amnesia by Bacopa monniera without qualifying the molecular details although some downstream molecules of LTP may be involved.

Jhe in Gryllus assimilis: cloning, sequence-activity associations and phylogeny

The 458 amino acid sequence of a mature JHE protein from the cricket Gryllus assimilis was identified after isolating the partial cDNA sequence encoding this protein from a fat body and midgut cDNA library. This hemimetabolan JHE sequence shows over 40% amino acid similarity to the known JHE sequences of several holometabolous insects. It also includes previously determined peptide sequences for G. assimilis JHE as well as two other motifs associated with JHE enzymes in holometabolous insects. The predicted molecular weight of the protein agrees with that of the JHE previously purified from G. assimilis. Partial genomic sequence encoding the Jhe contains two large (1330 and 2918bp) introns. No coding DNA sequence variation was observed over a 1293bp region between selected lines differing six to eight-fold in hemolymph JHE activity. However, a 19bp indel was found in one of the introns; the insertion was strongly associated with elevated hemolymph activity, both in the selected lines and in the F(2) progeny of crosses between them. Phylogenetic analyses localised the G. assimilis JHE to a clade containing dipteran and coleopteran JHEs, with lepidopteran JHEs occurring in a separate clade.

Discrimination of Normal and Malignant Mucosal Tissues of the Colon by Raman Spectroscopy

OBJECTIVE

The objective of this study was to evaluate the applicability of the discrimination parameters Mahalanobis distance, spectral residuals, and limit tests, developed by this group to differentiate normal from malignant colon tissues.

BACKGROUND DATA

Colon cancers are diagnosed using fiberoptic endoscopic localization and a subsequent histopathological examination of biopsied tissue, which is highly dependent on the skill and experience of the investigator. There exists a risk of missing significant lesions, especially with carcinoma in situ lesions. Raman spectroscopy, which is sensitive to biochemical variations in the samples and amenable to multivariate statistical tools, can lead to rapid and objective detection of colon cancer.

METHODS

A total of 102 spectra from 11 normal and 11 malignant ex vivo colon tissues were recorded by conventional near infrared (NIR) Raman spectroscopy (excitation wavelength of 785 nm). Spectral data were analyzed by principal components analysis (PCA) and other discriminating parameters, namely Mahalanobis distance, spectral residuals, and a multiparametric limit test approach.

RESULTS

Mean malignant spectra exhibit relatively stronger bands, suggesting the presence of additional biomolecules such as protein (stronger amide III and I), lipids (1,100, 1,300 cm(1)), and DNA (1,340, 1,470 cm(1)) versus those seen in normal tissue. Mean normal spectra indicate the presence of disordered structures (hump at 1,247 cm(1)). Scores of factor 1 gave good discrimination, and this is further fine-tuned by employing Mahalanobis distance and spectral residuals as discriminating parameters. A limit test approach provided unambiguous objective discrimination.

CONCLUSION

This study further supports the efficacy of Raman spectroscopy, in combination with a limit test, for discrimination of normal and malignant colon tissues. The multiparametric limit test approach is user-friendly, and a clinician or minimally trained individual could directly compare the unknown spectra against the available standard sets to make the decision instantly, objectively, and unambiguously.

Circulating tumor cells in patients with castration-resistant metastatic prostate cancer

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Background: Blood-based assays are urgently needed to provide molecular information on the specific targets expressed in tumor cells to optimize treatment selection. Antibody-capture technologies have been applied to isolate circulating tumor cells (CTC) from small volumes of peripheral blood from patients with progressive castrate metastatic prostate cancer. It has been demonstrated previously that CTC isolated from these patients represent authentic prostate cancer cells. Methods: CTC, positive for EpCAM (epithelial cellular adhesion molecule) and nuclear DAPI, and CD45 negative, were isolated from 120 patients with clinical castrate metastatic disease. All patients had rising PSA levels and were on stable treatment regimens at the time of CTC sampling. We tested the association between CTC counts and PSA levels, and the extent of disease to bone, and soft tissue metastasis by Wilcoxon rank sum. Fluorescence in situ hybridization was performed for AR and ERBB2 genes by an adapted method in CTC. Results: The average age in this patient cohort was 69 years, and median PSA at the time when CTC were drawn was 111 ng/mL (range 0.86–12147 ng/mL). The patterns of metastatic spread included disease in soft tissue only in 12 patients (10%), in bone and soft tissue in 67 (56%), and in bone only in 41 patients (34%). CTC counts ranged from 0 to 1958 cells per 7.5 mL of blood. A large number of patients (54, 45%) had 10 or more circulating tumor cells, while only 33 patients (27.5%) had 1 or less CTC per sample of blood. Significantly higher numbers of CTC were detected in patients with bone metastasis compared to those without bone metastasis (11 vs. 2.5, p<0.01). In patients with marked amplification of AR locus (five patients), tetraploidy was noted in the majority of cases (four cases). Two patients without AR amplification showed apparent tetraploidy, while no analyzed samples (nine) had amplification of ERBB2. Conclusions: The analysis of cancer-related gene alterations in CTC is feasible in a hospital-based laboratory. Further gene expression studies focused on the patients with higher numbers of CTC in correlation with clinical outcomes, as well as the investigation of CTC gene expression during specific treatments are under way.

No significant financial relationships to disclose.

Effect of salicylic acid on morphological and biochemical attributes in cowpea

Effects of salicylic acid (SA) on seed germination, seedling growth, flowering and biochemical activities were studied out in four cowpea (Vigna unguiculata) genotypes in control environments. The results revealed that both germination and seedling growth were negatively affected by 0.02%. SA application, however did not affect the size of full expanded buds, time of 50% flowering and date of flower initiation. A maximum increase in peroxidase (EC1.11.1.7) activity was observed in UPC 4200 over other genotypes. No significant change in the content of total soluble and intercellular fluid proteins was observed except in UPC 4200 genotype. SA induced accumulation of total soluble sugars more at flowering stage than at seed setting stage. It is evident from the present study that UPC 4200 genotype was more responsive to salicylic acid both in terms of increased peroxidase activity and less negative effect on morphological attributes, thus suggesting its wider use without negative impact on environment as salicylic acid has been reported in plants.

The culture of articular chondrocytes in hydrogel constructs within a bioreactor enhances cell proliferation and matrix synthesis

Bovine and human articular chondrocytes were seeded in 2% alginate constructs and cultured for up to 19 days in a rotating-wall-vessel (RWV) and under static conditions. Culture within the RWV enhanced DNA levels for bovine chondrocyte-seeded constructs when compared with static conditions but did not produce enhancement for human cells. There was a significant enhancement of glycosaminoglycans and hydroxyproline synthesis for both bovine and human chondrocytes. In all cases, histological analysis revealed enhanced Safranin-O staining in the peripheral regions of the constructs compared with the central region. There was an overall increase in staining intensity after culture within the RWV compared with static conditions. Type-II collagen was produced by both bovine and human chondrocytes in the peripheral and central regions of the constructs and the staining intensity was enhanced by culture within the RWV. A capsule of flattened cells containing type-I collagen developed around the constructs maintained under static conditions when seeded with either bovine or human chondrocytes, but not when cultured within the RWV bioreactor.

Risk factors for perforation in microbial corneal ulcers in north India

AIM

To identify predisposing factors leading to corneal perforation in patients with microbial keratitis.

METHOD

Two groups of 60 patients each, with perforated corneal ulcers and healed/healing corneal ulcers, respectively, were recruited in a case-control study conducted in northern India. The cases and controls were matched by age and time of presentation. A standardised proforma was used to identify potential predisposing factors for demographic, social, medical, ocular, and treatment history. All participants underwent a detailed ocular examination. Corneal scrapings were performed where relevant.

RESULTS

The characteristics associated with corneal perforation in microbial keratitis were outdoor occupation (p = 0.005), illiteracy (p = 0.02), excessive alcohol use (p = 0.03), history of "something falling into eye" (p = 0.003), trauma with vegetable matter (p = 0.008), vision less than counting fingers at referral (p<0.001), central location of ulcer (p<0.001), lack of corneal vascularisation (p<0.001), delay in starting initial treatment (p<0.001), failure to start fortified antibiotics (p<0.001), and monotherapy with fluoroquinolones (p = 0.002). The lack of corneal vascularisation (OR 6.4, 95% CI 4.2 to 13.5), delay in starting initial treatment (OR 35.6, 95% CI 6.9 to 68.2), and failure to start fortified antibiotics (OR 19.9, 95% CI 2.7 to 64.7) retained significance on a logistic regression model.

CONCLUSIONS

This study characterises microbial keratitis cases at increased risk of corneal perforation and reinforces the need for standardised referral and treatment protocols for patients with corneal ulcer on their first contact at primary care level in the developing world.