The high risk HPV16 L2 minor capsid protein has multiple transport signals that mediate its nucleocytoplasmic traffic

AbstractIn this study we examined the transport signals contributing to HPV16 L2 nucleocytoplasmic traffic using confocal microscopy analysis of enhanced green fluorescent protein—L2 (EGFP-L2) fusions expressed in HeLa cells. We confirmed that both nuclear localization signals (NLSs), the nNLS (1MRHKRSAKRTKR12) and cNLS (456RKRRKR461), previously characterized in vitro (Darshan et al., 2004), function independently in vivo. We discovered that a middle region rich in arginine residues (296SRRTGIRYSRIGNKQTLRTRS316) functions as a nuclear retention sequence (NRS), as mutagenesis of critical arginine residues within this NRS reduced the fraction of L2 in the nucleus despite the presence of both NLSs. Significantly, the infectivity of HPV16 pseudoviruses containing either RR297AA or RR297EE within the L2 NRS was strongly reduced both in HaCaT cells and in a murine challenge model. Experiments using Ratjadone A nuclear export inhibitor and mutation-localization analysis lead to the discovery of a leucine-rich nuclear export signal (462LPYFFSDVSL) mediating 16L2 nuclear export. These data indicate that HPV16 L2 nucleocytoplasmic traffic is dependent on multiple functional transport signals

Comparison of HER2 and Phospho-HER2 Expression between Biopsy and Resected Breast Cancer Specimens Using a Quantitative Assessment Method

<div><p>Background</p><p>HER2/Neu (ErbB-2) overexpression, which occurs in 15–20% of breast cancer cases, is associated with better response to treatment with the drug trastuzumab. PhosphoHER2 (pHER2) has been evaluated for prediction of response to trastuzumab. Both markers are heterogeneously detected and are potentially subject to loss as a consequence of delayed time to fixation. Here, we quantitatively assess both markers in core needle biopsies (CNBs) and matched tumor resections to assess concordance between the core and the resection and between HER2 and pHER2.</p><p>Methods</p><p>A selected retrospective collection of archival breast cancer cases yielded 67 cases with both core and resection specimens. Both HER2 and pTyr¹²⁴⁸HER2 were analyzed by the AQUA® method of quantitative immunofluorescence on each specimen pair.</p><p>Results</p><p>Both HER2 immunoreactivity (P<0.0001) and pTyr¹²⁴⁸HER2 immunoreactivity (P<0.0001) were lower in resections relative to CNB specimens. However, clinical implications of this change may not be evident since no case changed from 3+ (CNB) to negative (resection). Assessment of pTyr¹²⁴⁸HER2 showed no direct correlation with HER2 in either CNB or resection specimens.</p><p>Conclusions</p><p>The data suggest that measurement of both HER2 and phospho- Tyr¹²⁴⁸HER2, in formalin-fixed tissue by immunological methods is significantly affected by pre-analytic variables. The current study warrants the adequate handling of resected specimens for the reproducible evaluation of HER2 and pHER2. The level of pTyr¹²⁴⁸HER2, was not correlated to total HER2 protein. Further studies are required to determine the significance of these observations with respect to response to HER2 directed therapies.</p></div

Quantitative in situ measurement of estrogen receptor mRNA predicts response to tamoxifen.

Quantification of mRNA has historically been done by reverse transcription polymerase chain reaction (RT-PCR). Recently, a robust method of detection of mRNA utilizing in situ hybridization has been described that is linear and shows high specificity with low background. Here we describe the use of the AQUA method of quantitative immunofluorescence (QIF) for measuring mRNA in situ using ESR1 (the estrogen receptor alpha gene) in breast cancer to determine its predictive value compared to Estrogen Receptor α (ER) protein.Messenger RNA for ER (ESR1) and Ubiquitin C (UbC) were visualized using RNAscope probes and levels were quantified by quantitative in situ hybridization (qISH) on two Yale breast cancer cohorts on tissue microarrays. ESR1 levels were compared to ER protein levels measured by QIF using the SP1 antibody.ESR1 mRNA is reproducibly and specifically measurable by qISH on tissue collected from 1993 or later. ESR1 levels were correlated to ER protein levels in a non-linear manner on two Yale cohorts. High levels of ESR1 were found to be predictive of response to tamoxifin.Quantification of mRNA using qISH may allow assessment of large cohorts with minimal formalin fixed, paraffin embedded tissue. Exploratory data using this method suggests that measurement of ESR1 mRNA levels may be predictive of response to endocrine therapy in a manner that is different from the predictive value of ER

Comparison between pTyr¹²⁴⁸HER2 and HER2 AQUA.

<p>Scatter plot of HER2 and pTyr¹²⁴⁸HER2 AQUA scores (CNBs, open diamonds; Resections, filled triangles). Lines in the graph represent the noise cut points of either HER2 or pTyr¹²⁴⁸HER2.</p

HER2 and pTyr¹²⁴⁸HER2 AQUA score comparisons between CNBs and resections.

<p>Note: Abbreviation: CNB. Core Needle Biopsy; R: Resection.</p

Average ranges of clinicalpathological characteristics of 67 patients diagnosed with Breast Cancer.

<p>Average ranges of clinicalpathological characteristics of 67 patients diagnosed with Breast Cancer.</p

Expression of HER2 in tumor resections compared to CNBs.

<p>AQUA HER2 scores of 63 pairs of CNB (open bars) and tumor resection (filled bars) were assessed. Average FOVs of CNB: average number of FOVs included in analysis of CNB; Average FOVs of Resection: average number of FOVs included in analysis of tumor resection specimens. The noise cut point is marked with a solid line. Each AQUA score represents the mean ±95% CI. The number of pairs where resections are higher, lower than CNBs, or equal to those of CNBs are listed in inset.</p