Application of droplet digital PCR in minimal residual disease monitoring of rare fusion transcripts and mutations in haematological malignancies.

Leukaemia of various subtypes are driven by distinct chromosomal rearrangement or genetic abnormalities. The leukaemogenic fusion transcripts or genetic mutations serve as molecular markers for minimal residual disease (MRD) monitoring. The current study evaluated the applicability of several droplet digital PCR assays for the detection of these targets at RNA and DNA levels (atypical BCR::ABL1 e19a2, e23a2ins52, e13a2ins74, rare types of CBFB::MYH11 (G and I), PCM1::JAK2, KMT2A::ELL2, PICALM::MLLT10 fusion transcripts and CEBPA frame-shift and insertion/duplication mutations) with high sensitivity. The analytical performances were assessed by the limit of blanks, limit of detection, limit of quantification and linear regression. Our data demonstrated serial MRD monitoring for patients at molecular level could become "digitalized", which was deemed important to guide clinicians in treatment decision for better patient care.

Role of PCDH10 and its hypermethylation in human gastric cancer.

Epigenetic changes of genomic DNA are involved in the development and progression of many cancers. Aberrant methylation of CpG islands in the promoter regions of certain tumor-suppressor genes (TSG) is frequently observed in cancer cells. Protocadherin 10 (PCDH10), a member of the cadherin superfamily, is a recently identified putative TSG. PCDH10 is frequently silenced in many solid tumors. However, the role of PCDH10 in gastric cancer is largely unknown. In this study, we examined the expression and methylation status of PCDH10 in gastric cancer cells and tissues by real time PCR and methylation-specific PCR (MSP), and then investigated the biological function of PCDH10. We found that the expression of PCDH10 was markedly reduced in gastric cancer cells and tissues. The reduced expression correlated with hypermethylation of this gene in its promoter region, as demonstrated by MSP and bisulfite genomic sequencing (BGS) analysis. In addition, pharmacological demethylation using 5-Aza restored the expression of PCDH10 in gastric cancer cells. Over-expression of PCDH10 in gastric cancer cells suppressed cell proliferation and migration, but did not cause marked apoptosis. Over-expression of PCDH10 also suppressed growth of xenograft tumors in nude mice. Thus, PCDH10 functions as a TSG in gastric cancer, and might be a useful target for cancer therapy.

Vision-threatening complications of nasal T/NK lymphoma.

PURPOSE: Nasal T/NK lineage lymphoma, previously known as lethal midline granuloma, is common among Oriental, Native-American, and Hispanic patients and is invariably associated with Epstein-Barr virus. Nasal localization, local necrosis, angioinvasion, and aggressive behavior are hallmarks of the disease. Ophthalmologic symptoms and signs may precede lymphoma diagnosis or complicate its disease course. We aim to define the incidence and disease pattern of ophthalmic involvement. DESIGN: Retrospective single-institution consecutive interventional case series. METHODS: Records of all lymphoma patients from 1996 to 2000 were retrieved from a computer database, and the primary sites and lineage were reviewed. Nasal T/NK lymphoma was defined by a combination of morphology, positive CD3 epsilon and CD56 expression, in situ hybridization staining for Epstein-Barr virus expressed RNA (EBER), and negative staining for B cell markers (CD20 and CD79a). RESULTS: Thirty-five consecutive patients with T/NK lymphoma were identified. Primary nasal or nasopharyngeal disease was found in 24 patients. Six (25%) of the 24 patients suffered from vision-threatening complications of two distinct categories, namely uveitis/vitritis and orbital infiltration. The former preceded the diagnosis of lymphoma in two patients and also led to novel ocular complications like rhegmatogenous retinal detachment and macular hole that were successfully managed by ocular surgery. In four patients, orbital extension of lymphomatous disease accompanied biopsy-proven in-field disease relapse. Generally, the prognosis is grave, but remission can still be achieved with aggressive combined chemotherapy and radiotherapy. CONCLUSION: Both oncologists and ophthalmologists should be aware of ocular complications when dealing with known or suspected cases of T/NK lymphoma at diagnosis and relapse. Regular ophthalmic assessment of these patients is warranted.