Immunohistochemical analysis of cell death pathways in gastrointestinal adenocarcinoma

Caspase-8 and caspase-9 play crucial roles in the extrinsic and intrinsic apoptotic pathways, respectively. The nuclear translocation of apoptosis-inducing factor (AIF) is involved in caspase-independent apoptosis. Microtubule-associated protein 1 light chain 3 (LC3) plays a pivotal role in autophagy. In the present study, we analyzed the expression of cleaved caspase-8 (CC8), cleaved caspase-9 (CC9), AIF, and LC3 in 160 gastrointestinal adenocarcinomas. The nuclear expression of AIF was rare. The expression of CC8 in gastric and colorectal adenocarcinomas did not differ, whereas the percentage of CC9-positive tumors in gastric adenocarcinomas was significantly higher than in colorectal adenocarcinomas. In contrast, the percentage of LC3-positive tumors in gastric adenocarcinomas was significantly lower than in colorectal adenocarcinomas. CC8 and CC9 occasionally co-existed in the same tumor cells in gastric adenocarcinoma. However, LC3-positive tumor cells in colorectal adenocarcinomas were constantly negative for CC8. No correlation was identified between the expression of any markers and clinicopathological parameters. These results suggest that different cell death pathways are activated in a manner that depends upon the primary site and cell type. The extrinsic and intrinsic apoptotic pathways may be mutually regulated in gastric adenocarcinomas. Also, autophagy may function as a cellular guardian to avoid apoptosis in colorectal adenocarcinomas.     

Unnatural base pair systems for sensing and diagnostic applications

Expansion of the genetic alphabet by an unnatural base pair system provides a platform for the site-specific, enzymatic incorporation of extra, functional components into nucleic acids. Recently, several unnatural base pairs that exhibit high fidelity and efficiency in PCR have been developed. Functional groups of interest, such as fluorescent dyes, can be linked to the unnatural bases, and the modified base substrates are site-specifically incorporated into nucleic acids by polymerases. Furthermore, unique unnatural base pairs between fluorophore and quencher base analogs have been developed for imaging PCR amplification and as molecular beacons. Here, we describe the recent progress in the development of unnatural base pairs that function in PCR amplification and their applications as sensing and diagnostic tools.     

Pustulosis palmaris et plantaris successfully treated with leukotriene antagonist

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Evaluation of gefitinib efficacy according to body surface area in patients with non-small cell lung cancer harboring an EGFR mutation

Background

Exon 19 deletions and L858R point mutation are the most commonly encountered active epidermal growth factor receptor (EGFR) mutations in non-small cell lung cancer (NSCLC), and they predict greater efficacy of gefitinib therapy. The objective of this study was to evaluate whether body surface area (BSA) affects the efficacy of gefitinib in patients with NSCLC harboring an active EGFR mutation.

Methods

We reviewed the medical records of consecutive patients with advanced NSCLC harboring an active EGFR mutation who received gefitinib monotherapy. The median BSA value was used as the cutoff value to evaluate the impact of BSA on the efficacy of gefitinib.

Results

The median BSA of the 103 NSCLC patients harboring an active EGFR mutation was 1.45 m². The overall response rate, progression-free survival (PFS), and median survival time (MST) were 65.0 %, 11.3 months, and 26.2 months, respectively. There were no significant differences in clinical outcomes between the high-BSA group (BSA ≥ 1.45 m²) and low-BSA group (BSA < 1.45 m²), i.e., the response rates was 60.0 % and 69.8 %, respectively (P = 0.20), and their MST was 24.7 and 26.2 months, respectively (P = 0.78). Although BSA was predictive of PFS between high-BSA group and low-BSA group in the univariate analysis (9.0 and 12.2 months, P = 0.04), the multivariate analysis identified only performance status and smoking status as independent predictors of PFS.

Conclusions

The efficacy of gefitinib in patients with NSCLC harboring an EGFR mutation does not differ according to their BSA.     

Horrifying Basal Cell Carcinoma: Cytological,Immunohistochemical, and Ultrastructural Findings

Basal cell carcinoma (BCC) is a slow-growing and frequently occurring tumor of the eyelids. Among BCC cases, there is a subtype of aggressive cases called horrifying BCC (HBCC). There are also rare BCC cases that show neuroendocrine differentiation. Here, we describe a case of HBCC with neuroendocrine differentiation. The patient, a 41-year-old woman, presented with abnormal left eye tearing and left cheek pain. On computed tomography imaging, a tumor that extended to the left orbit was detected in the left cheek. On cytological examination of fine-needle aspiration (FNA) samples, the tumor cells were observed as sheet-like clusters and single bare nuclei with a clear background; peripheral palisading was not clearly seen. On examination of the biopsy specimen taken after FNA, the tumor was found to be composed of cancer cell nests with scattered peripheral palisading in the dermis. Immunohistochemically, the tumor cells were positive for cytokeratin (CK) 7 and CD56 and were negative for CK20, synaptophysin, and chromogranin A. Membrane-bound dense-core granules were detected on ultrastructural study. A HBCC case with neuroendocrine differentiation has not been previously reported. The correlation between the presence of neuroendocrine differentiation in HBCC and patient prognosis should be further studied.Key words: Horrifying basal cell carcinoma, Cytology, Immunocytochemistry, Electron microscopy     

The anti-HER3 antibody patritumab abrogates cetuximab resistance mediated by heregulin in colorectal cancer cells

We previously showed that tumor-derived heregulin, a ligand for HER3, is associated with both de novo and acquired resistance to cetuximab. We have now examined whether patritumab, a novel neutralizing monoclonal antibody to HER3, is able to overcome such resistance. Human colorectal cancer (DiFi) cells that are highly sensitive to cetuximab were engineered to stably express heregulin by retroviral infection, and the effects of cetuximab and patritumab on the resulting DiFi-HRG cells were examined. DiFi-HRG cells released substantial amounts of heregulin and showed resistance to cetuximab. Cetuximab alone inhibited EGFR and ERK phosphorylation in DiFi-HRG cells, but it had no effect on the phosphorylation of HER2, HER3, or AKT, suggesting that sustained AKT activation by HER2 and HER3 underlies cetuximab resistance in these cells. In contrast, patritumab in combination with cetuximab markedly inhibited the phosphorylation of EGFR, HER2, HER3, ERK, and AKT. The combination therapy also inhibited the growth of DiFi-HRG tumor xenografts in nude mice to a greater extent than did treatment with either drug alone. Activation of HER2-HER3 signaling associated with the operation of a heregulin autocrine loop confers resistance to cetuximab, and patritumab is able to restore cetuximab sensitivity through inhibition of heregulin-induced HER3 activation.     

Feasibility study of gemcitabine plus docetaxel in advanced or recurrent uterine leiomyosarcoma and undifferentiated endometrial sarcoma in Japan

Background

Uterine leiomyosarcoma (LMS) and undifferentiated endometrial sarcoma (UES) are rare, aggressive malignancies. Both are treated similarly; however, few chemotherapy agents are effective. Recently, the combination of gemcitabine (900 mg/m², days 1 and 8) plus docetaxel (100 mg/m², day 8) with granulocyte colony-stimulating factor (G-CSF, 150 μg/m², days 9–15) has been shown to have activity in LMS. In Japan, neither prophylactic G-CSF at a dose of 150 μg/m² nor docetaxel at a dose of 100 mg/m² are approved for use. For this reason, we evaluated the combination of 900 mg/m² gemcitabine plus 70 mg/m² docetaxel regimen without prophylactic G-CSF support in advanced or recurrent LMS and UES in Japanese patients.

Methods

Eligible women with advanced or recurrent LMS and UES were treated with 900 mg/m² gemcitabine on days 1 and 8, plus 70 mg/m² docetaxel on day 8, every 3 weeks. The primary endpoint was overall response rate, defined as a complete or partial response.

Results

Of the eleven women enrolled, 10 were evaluated for a response. One complete response and 2 partial responses were observed (30 %) with an additional 4 (40 %) having stable disease. Mean progression-free survival was 5.4 months (range 1.3–24.8 months), and overall survival was 14 months (range 5.3–38.4 months). Grade 4 neutropenia was the major toxicity (50 %). The median number of cycles was 5 (range 2–18). Twenty-two cycles (44 %) employed G-CSF.

Conclusion

The gemcitabine plus docetaxel regimen without prophylactic G-CSF support was tolerable and highly efficacious in Japanese patients with advanced or recurrent LMS and UES.