Quantifying heterogeneities within cell populations is important for many fields including cancer research and neurobiology; however, techniques to isolate individual cells are limited. Here, we describe a high-throughput, non-disruptive, and cost-effective isolation method that is capable of capturing individually targeted cells using widely available techniques. Using high-resolution microscopy, laser microcapture microscopy, image analysis, and machine learning, our technology enables scalable molecular genetic analysis of single cells, targetable by morphology or location within the sample.

SUMMARY:We have delineated regions of interest at chromosome 2q21.2, 2q36.3, and 2q37.1 by deletion mapping of 114 urothelial cancers (UC). Altogether, 17%, 18%, and 63% of the G1, G2, and G3 tumors displayed loss of heterozygosity at chromosome 2q, respectively, The region at 2q21.2 was narrowed down to the LRP1B gene (NT_005129.6). Hemi-and homozygous deletion at the LRP1B gene region was seen in 31 of 114 UCs. Only 8% of the UCs with G1 and none with G2 tumors showed loss of heterozygosity at the LRP1B gene, whereas 49% of the G3 UCs had allelic loss at this region. RT-PCR analysis of the LRP1B gene showed the lack of expression of several exons in 2 of 9 cases analyzed. Our analysis suggests that the LRP1B gene is a candidate tumor suppressor gene in UCs. (Lab Invest 2002, 82:639 -643).C ancer of the urinary bladder is one of the most common tumors in the Western world. The majority of urothelial cancers (UC) are diagnosed as noninvasive tumors (Ta), whereas 20% to 25% of the cases show an invasive growth (T1-4) at the time of first presentation. From the clinical point of view, the question arises whether these two major groups of tumors are distinct entities or correspond to different stages of progression of a single tumor entity. Pioneering cytogenetic analyses before the chromosome banding era have suggested that the number of gross karyotype alterations predicts the clinical course of UCs, for example, recurrency and progression (Falor and Ward, 1978;Lamb, 1967). Later, several studies showed that allelic changes at specific chromosomal regions and alterations of tumor suppressor genes, such as PTEN, RB, and TP53, correlate with stage and grade of bladder cancers (for review see Knowles, 1999). Comparative genomic hybridization (CGH) studies also suggested quantitative differences of genetic changes, including DNA losses at chromosome 2q22-33, 2q32-qter, and 2q34-qter regions, between the noninvasive and invasive bladder cancers (Richter et al, 1997Simon et al, 1998Simon et al, , 2000. Loss of heterozygosity (LOH) at chromosome 2q is also associated with aggressive growth of head and neck and non-small cell lung carcinomas (Ransom et al, 1998;Shiseki et al, 1994). Recently, Liu et al (2000) identified a putative tumor suppressor gene LRP1B from the chromosome 2q21.2 region that was found to be homozygously deleted in several cancer cell lines, including the bladder cancer cell line VM-CUB-2. To delineate putative tumor suppressor gene regions, we analyzed 114 UCs for 20 microsatellite loci at the chromosome 2q including those from the LRP1B region. We identified three distinct regions of LOH in 40% of tumors and found a correlation between LOH at chromosome 2q and tumor grade. Results Three Target Regions of Allelic Loss at Chromosome 2qCGH analysis of 18 Grade 3 (G3) UCs of this series revealed a gain at chromosome 2p in 7 cases and loss of DNA at chromosome 2q in 11 cases (one example is shown in Fig. 2). Therefore, we evaluated score 2 at chromosome 2p as a duplication of one allele, but at chromoso...

We sequenced the entire mitochondrial genome in 8 chromophobe renal cell carcinomas (RCCs) and corresponding normal kidneys. Our study disclosed 68 known and 45 new sequence variations occurring 132 and 45 times, respectively. We found 6 somatic nucleotide changes in 5 out of the 8 chromophobe RCCs. One A --> T substitution occurred in the D-loop region and an insertion of a 9-bp sequence in the noncoding region of the MTNC7. One G --> A substitution and one C --> T substitution were seen in the MTRNR1 and MTRNR2 genes, respectively. One C deletion in MTND5 and one T insertion in the MTND3 gene resulted in frameshift mutations in two tumors. All somatic alterations, with the exception of the 9-bp insertion, were heteroplasmic changes. Although somatic mtDNA mutations are found in chromophobe RCCs, their role in the maintenance of tumor cell phenotype or in tumorigenesis remains to be elucidated.

To answer major questions of cell biology, it is often essential to understand the complex phenotypic composition of cellular systems precisely. Modern automated microscopes produce vast amounts of images routinely, making manual analysis nearly impossible. Due to their efficiency, machine learning-based analysis software have become essential tools to perform single-cell-level phenotypic analysis of large imaging datasets. However, an important limitation of such methods is that they do not use the information gained from the cellular micro- and macroenvironment: the algorithmic decision is based solely on the local properties of the cell of interest. Here, we present how various features from the surrounding environment contribute to identifying a cell and how such additional information can improve single-cell-level phenotypic image analysis. The proposed methodology was tested for different sizes of Euclidean and nearest neighbour-based cellular environments both on tissue sections and cell cultures. Our experimental data verify that the surrounding area of a cell largely determines its entity. This effect was found to be especially strong for established tissues, while it was somewhat weaker in the case of cell cultures. Our analysis shows that combining local cellular features with the properties of the cell’s neighbourhood significantly improves the accuracy of machine learning-based phenotyping.

Paraneoplastic nephropathy is rarely associated with human tumors. Little is known about the pathogenetic background of this relationship. To our knowledge, no conclusive study of the association of potentially ‘immunogenic’ renal cell carcinoma (RCC) and paraneoplastic nephropathy has been published. For this reason, we performed an immunohistochemical analysis of native resected kidneys of 60 patients with RCC, paying special attention to their pre- and postoperative records. Sixteen (27%) of the 60 tumor patients had immune complex nephropathy (11 IgA nephropathy [IgA NP] and 5 focal segmental glomerulosclerosis [FSGS]). Preoperative proteinuria and/or hematuria observed in 11 of 16 cases disappeared in 6 IgA NP patients within a 2- to 3-month follow-up after nephrectomy. Eleven of 16 tumors stained with the anti human immunoglobulin (IgA or IgM) of the same isotype as that present in glomerular immune complexes. In 3 IgA NP patients RCC-associated von Hippel-Lindau (VHL) protein and IgA staining were found simultaneously in the tumor and glomeruli, with the clinical and laboratory findings disappearing after nephrectomy. Immune injury of the glomeruli due to a tumor-induced antigen-antibody response was demonstrated in these 3 IgA NP patients.