Deming He

Trastuzumab anti-tumor efficacy in patient-derived esophageal squamous cell carcinoma xenograft (PDECX) mouse models.

BackgroundTrastuzumab is currently approved for the clinical treatment of breast and gastric cancer patients with HER-2 positive tumors, but not yet for the treatment of esophageal carcinoma patients, whose tumors typically show 5 ~ 35% HER-2 gene amplification and 0 ~ 56% HER-2 protein expression. This study aimed to investigate the therapeutic efficacy of Trastuzumab in patient-derived esophageal squamous cell carcinoma xenograft (PDECX) mouse models.MethodsPDECX models were established by implanting patient esophageal squamous cell carcinoma (ESCC) tissues into immunodeficient (SCID/nude) mice. HER-2 gene copy number (GCN) and protein expression were determined in xenograft tissues and corresponding patient EC samples by FISH and IHC analysis. Trastuzumab anti-tumor efficacy was evaluated within these PDECX models (n = 8 animals/group). Furthermore, hotspot mutations of EGFR, K-ras, B-raf and PIK3CA genes were screened for in the PDECX models and their corresponding patient’s ESCC tissues. Similarity between the PDECX models and their corresponding patient’s ESCC tissue was confirmed by histology, morphology, HER-2 GCN and mutation.ResultsNone of the PDECX models (or their corresponding patient’s ESCC tissues) harbored HER-2 gene amplification. IHC staining showed HER-2 positivity (IHC 2+) in 2 PDECX models and negativity in 3 PDECX models. Significant tumor regression was observed in the Trastuzumab-treated EC044 HER-2 positive model (IHC 2+). A second HER-2 positive (IHC 2+) model, EC039, harbored a known PIK3CA mutation and showed strong activation of the AKT signaling pathway and was insensitive to Trastuzumab treatment, but could be resensitised using a combination of Trastuzumab and AKT inhibitor AZD5363. In summary, we established 5 PDECX mouse models and demonstrated tumor regression in response to Trastuzumab treatment in a HER-2 IHC 2+ model, but resistance in a HER-2 IHC 2+/PIK3CA mutated model.ConclusionsThis study demonstrates Trastuzumab-induced tumor regressions in HER-2 positive tumors, and highlights PIK3CA mutation as a potential resistance mechanism to Trastuzumab treatment in pre-clinical patient-derived EC xenograft models.

An alternative high output tissue microarray technique

BackgroundTissue microarray (TMA) is a high throughput research tool, which has greatly facilitated and accelerated in situ tissue analyses. However, its productivity has been restricted due to the confined thickness of traditional donor block. Here, we introduce an improved high output TMA method that is applicable to a broader range of tissue samples.MethodsIn this method, a 3.6 cm long and 2.7 cm wide recipient block with 88 square lattices (3 mm in width) was first prepared using several commercial instruments. A 2 mm wide and 6 mm long tissue rod was then prepared using a self-made blade-shaped knife from each paraffin embedded donor block of gastrointestinal stromal tumors. These rods were manually arrayed one by one into the corresponding lattices of the 60°C pre-softened recipient block with the guide of holes drilled with a steel needle. A 70-rod TMA was made to testify this method.ResultsThe prepared TMA had well defined array configurations, good tissue morphology and fully preserved proteins and DNA. A total of 500–1000 TMA sections could be easily obtained from a TMA block.ConclusionThis low-cost and time-saving method provides an alternative sampling tool for high output TMA.Virtual SlidesThe virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1979605867857990

Subsequent intra-abdominal fibromatosis mimicking recurrent gastrointestinal stromal tumor.

AbstractIntra-abdominal fibromatosis (IAF) commonly develops in patients who had abdominal surgery. In rare instances, it occurs subsequent to gastrointestinal stromal tumor (GIST). This special situation has clinical significance in imatinib era. About 1000 patients with GIST in our institution from 1993 to 2010 were re-evaluated based on their clinical and pathological data, the treatment strategies and the follow-up information. We identified 2 patients who developed IAF after GIST resection. Patient 1 was a 54 year-old male and had 5 cm × 4.5 cm × 3.5 cm jejunal GIST excised on February 22, 1994. Three years later, an abdominal mass with 7 cm × 6 cm × 3 cm was identified. He was diagnosed as recurrent GIST from clinical point of view. After excision, the second tumor was confirmed to be IAF. Patient 2 was a 45-year-old male and had 6 cm × 4 cm × 3 cm duodenal GIST excised on August 19, 2008. One year later, a 4 cm mass was found at the original surgical site. The patient refused to take imatinib until the tumor increased to 8 cm six months later. The tumor continued to increase after 6 months’ imatinib therapy, decision of surgical resection was made by multidisciplinary team. The second tumor was confirmed to be IAF with size of 17 cm × 13 cm × 11 cm. Although IAF subsequent to GIST is very rare, it is of clinical significance in imatinib era as an influencing factor for making clinical decision.Virtual slidesThe virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1076715989961803