Characterization of the Arabidopsis mutant oligocellula6-D reveals the importance of leaf initiation in determining final leaf size.

The leaf is a determinate organ with a final size under genetic control. Numerous factors that regulate final leaf size have been identified in Arabidopsis thaliana; although most of these factors play their roles during the growth of leaf primordia, much less is known about leaf initiation and its effects on final leaf size. In this study, we characterized oligocellula6-D (oli6-D), a semidominant mutant of Arabidopsis thaliana with smaller leaves than the wild type due to its reduced leaf cell numbers. A time-course analysis showed that oli6-D had approximately 50% fewer leaf cells, even immediately after leaf initiation; this difference was maintained throughout leaf development. Next-generation sequencing showed that oli6-D had chromosomal duplication involving 2-kbp and 3-Mbp regions of chromosomes 2 and 4, respectively. Several duplicated genes examined had approximately twofold higher expression levels, and at least one gene acquired a new intron/exon structure due to a chromosome fusion event. oli6-D showed reduced auxin responses in leaf primordia, primary roots, and embryos as well as reduced apical dominance and partial auxin-resistant root growth. CRISPR/Cas9-mediated genome editing enabled the removal of a 3-Mbp duplicated segment, the largest targeted deletion in plants thus far. As a result, oli6-D restored the wild-type leaf phenotypes, demonstrating that oli6-D is a gain-of-function mutant. Our results suggest a new regulatory point of leaf size determination that functions at a very early stage of leaf development and is negatively regulated by one or more genes located in the duplicated chromosomal segments.

Outcomes of Window Therapy with Carboplatin and Ifosfamide for Pediatric Osteosarcoma: A Case Series.

For the treatment of osteosarcoma, cisplatin (CDDP) can be substituted by carboplatin (CBDCA) to reduce toxicity. We report a single institution experience of CBDCA-based regimen. Two to three cycles of CBDCA + ifosfamide (IFO) therapy (window therapy) were administered as neoadjuvant therapy for osteosarcoma. Depending on the response of window therapy, the subsequent protocols were determined; for good responders, surgery is performed, and postoperative therapies with CBDCA + IFO, adriamycin (ADM) and high-dose methotrexate (MTX) were administered; for stable disease, the postoperative regimens were advanced before surgery, and the remaining amount of postoperative chemotherapy is deduced; for progressive disease, CBDCA-based regimen is changed to CDDP-based regimen. From 2009 to 2019, seven patients were treated with this protocol. During the window therapy, two patients (28.6%) were assessed as good responders and completed the regimen as planned. Four patients (57.1%) had stable disease, and the chemotherapy schedules were modified. One patient (14.2%) with progressive disease was shifted to the CDDP-based regimen. At final follow-up, four patients showed no evidence of disease and three patients died of the disease. Since the efficacy during window therapy was limited, a CBDCA-based regimen in the neoadjuvant setting was considered insufficient for performing adequate surgery.

Anomalous patterns of Saffman-Taylor fingering instability during a metastable phase separation.

Phase separation is important in biology, biochemistry, industry, and other areas and is divided into two types: a spinodal decomposition type and a nucleation and growth type. The spinodal decomposition type phase separation occurs under the thermodynamically unstable conditions, and the nucleation and growth type phase separation occurs under thermodynamically metastable conditions. On the other hand, when a less viscous fluid displaces a more viscous one in porous media, the interface of the two fluids becomes hydrodynamically unstable and forms a finger-like pattern. The coupling of the hydrodynamic instability with the thermodynamic instability has been studied. It is reported that the hydrodynamic instability under thermodynamically unstable conditions, where spinodal decomposition type phase separation occurs, creates multiple moving droplets with a radius of 3-4 mm because of the spontaneous convection induced by the Korteweg force, which is driven by a compositional gradient during phase separation. However, the hydrodynamic instability under metastable conditions, where the phase separation of nucleation and growth type occurs, is still unrevealed. In this study, we applied fingering instability (hydrodynamic instability) under the metastable conditions, where the patterns are changed from fingering or droplets to anomalous patterns such as tip-widening or needle-like (top-pointed) fingering patterns when the initial concentration is metastable, which is considered near a binodal curve. These patterns are ubiquitous in nature, similar to dendrite crystals (snowflakes) or our body's cells. Thus, the patterns created can be controlled through hydrodynamic conditions such as the injection flow and thermodynamic conditions such as spinodal decomposition (thermodynamically unstable conditions) and metastable conditions.

Post-Traumatic West Syndrome due to Abusive Head Trauma in Two Infants with Different Brain Imaging Findings.

Abusive head trauma (AHT), commonly known as shaken baby syndrome, is a cranial injury of infants and young children. AHT is an important cause of morbidity and mortality in young children, particularly those younger than 12 months of age. We describe two patients who developed West syndrome, which is a severe epilepsy syndrome composed of the triad of infantile spasms, hypsarrhythmia on electroencephalography, and developmental arrest or regression, possibly attributable to AHT. Case 1 was a 5-month-old boy presented with generalized convulsive status epilepticus when a babysitter had cared for him. Brain magnetic resonance imaging (MRI) exhibited a subdural hemorrhage with diffuse brain edema and a midline shift highly suggestive of AHT. He developed West syndrome at the age of 10 months. Case 2 was a 6-month-old girl presented infantile spasms and diagnosed with West syndrome. Although she had poor weight gain due to inadequate care by her mother, there were no history of trauma, no cutaneous finding, and no developmental delay. Brain MRI performed when West syndrome was diagnosed revealed contusional tears highly suggestive of AHT. The MRI finding indicated that contusional tears had occurred 1~2 months before the development of West syndrome. There are no reports of West syndrome due to contusional tears. AHT may be an important risk factor for postnatal West syndrome. It is noteworthy that evidence of AHT was found only after West syndrome onset, as in Case 2. The onset of West syndrome may contribute to the finding that AHT had occurred earlier.

Immunohistochemical expression profiles of solute carrier transporters in alpha-fetoprotein-producing gastric cancer.

AIMS: Alpha-fetoprotein (AFP)-producing gastric cancer (GC) is an aggressive tumour with high rates of liver metastasis and poor prognosis, and for which a validated chemotherapy regimen has not been established. Drug uptake by solute carrier (SLC) transporters is proposed as one of the mechanisms involved in sensitivity to chemotherapy. In this study, we aimed to develop important insights into effective chemotherapeutic regimens for AFP-producing GC. METHODS AND RESULTS: We evaluated immunohistochemically the expression levels of a panel of SLC transporters in 20 AFP-producing GCs and 130 conventional GCs. SLC transporters examined were human equilibrative nucleoside transporter 1 (hENT1), organic anion transporter 2 (OAT2), organic cation transporter (OCT) 2, OCT6 and organic anion-transporting polypeptide 1B3 (OATP1B3). The rates of high expression levels of hENT1 (hENT1high ) and OAT2 (OAT2high ) were statistically higher in AFP-producing GC, compared with conventional GC. When analysing hENT1 and OAT2 in combination, hENT1high /OAT2high was the most particular expression profile for AFP-producing GC, with a greater significance than hENT1 or OAT2 alone. However, no significant differences in OCT2, OCT6 or OATP1B3 levels were detected between AFP-producing and conventional GCs. However, immunoreactivity for hENT1, OAT2 and OCT6 tended to be increased in GC tissues compared with non-neoplastic epithelia. CONCLUSIONS: Because hENT1 and OAT2 are crucial for the uptake of gemcitabine and 5-fluorouracil, respectively, our results suggest that patients with AFP-producing GC could potentially benefit from gemcitabine/fluoropyrimidine combination chemotherapy. Increased expression of hENT1, OAT2 and OCT6 may also be associated with the progression of GC.

Organic cation transporter 2 for predicting cisplatin-based neoadjuvant chemotherapy response in gastric cancer.

Some studies have shown the usability of neoadjuvant chemotherapy (NAC) in gastric cancer (GC). Nevertheless there are a few predictive markers of the effectiveness of NAC in GC. The aim of this study is to assess the predictive impact of organic cation transporter 2 (OCT2) expression on response to neoadjuvant chemotherapy (NAC) in gastric cancer. We retrospectively assessed 66 patients with advanced gastric cancer received NAC with S-1/cisplatin or paclitaxel/cisplatin. Expression levels of OCT2 were assessed by immunohistochemistry in pre-chemotherapy biopsies and correlated with clinicopathologic parameters including pathologic response. High expression level of OCT2 (OCT2(high)) was significantly associated with intestinal type according to Laurén classification (P = 0.03) and low histologic grade (P = 0.03). In univariate analysis of the entire cohort, no variables showed any significant association with a response, although intestinal type (P = 0.09), low histologic grade (P = 0.09), and OCT2(high) (P = 0.07) tended to be more frequent in responders compared with non-responders. When the two treatment groups were separately assessed in the univariate analysis, a significantly higher rate of OCT2(high) was observed in responders compared with non-responders in the S-1/cisplatin group (P = 0.001). In addition, multivariate analysis identified OCT2(high) as the sole independent predictor of response (P = 0.04). However, in the paclitaxel/cisplatin group, no variables were associated with response. Taken together, our results suggest that OCT2(high) may represent a potential predictor of response to NAC with S-1/cisplatin in gastric cancer.

Impact of Expression Levels of Platinum-uptake Transporters Copper Transporter 1 and Organic Cation Transporter 2 on Resistance to Anthracycline/Taxane-based Chemotherapy in Triple-negative Breast Cancer.

Adding platinum drugs to anthracycline/taxane (ANC-Tax)-based neoadjuvant chemotherapy (NAC) improves pathological complete response (pCR) rates in triple-negative breast cancer (TNBC). Copper transporter 1 (CTR1) and organic cation transporter 2 (OCT2) critically affect the uptake and cytotoxicity of platinum drugs. We immunohistochemically determined CTR1 and OCT2 levels in pre-chemotherapy biopsies from 105 patients with HER2-negative breast cancer treated with ANC-Tax-based NAC. In the TNBC group, Ki-67(high) [pathological good response (pGR), P = 0.04] was associated with response, whereas CTR1(high) (non-pGR, P = 0.03), OCT2(high) (non-pGR, P = 0.01; non-pCR, P = 0.03), and combined CTR1(high) and/or OCT2(high) (non-pGR, P = 0.005; non-pCR, P = 0.003) were associated with non-response. In multivariate analysis, Ki-67(high) was an independent factor for pGR and CTR1 for non-pGR. Combined CTR1/OCT2 was a strong independent factor for non-pGR. However, no variables were associated with response in luminal BC. These results indicate that platinum uptake transporters are predominantly expressed in ANC-Tax-resistant TNBCs, which implies that advantage associated with adding platinum drugs may depend on high drug uptake.

High expression of organic anion transporter 2 and organic cation transporter 2 is an independent predictor of good outcomes in patients with metastatic colorectal cancer treated with FOLFOX-based chemotherapy.

Although metastatic colorectal cancer (mCRC) is commonly treated with 5-fluorouracil (5-FU)/leucovorin/oxaliplatin (FOLFOX), their response to FOLFOX varies, and no biomarkers predictive of treatment outcome have been validated. Organic anion transporter 2 (OAT2) and organic cation transporter 2 (OCT2) are critical determinants in uptake of 5-FU and oxaliplatin, respectively. In this study, we evaluated whether OAT2 and OCT2 levels can predict effectiveness of FOLFOX-based therapy. We retrospectively assessed 90 patients with mCRC who were treated with first-line FOLFOX with or without bevacizumab. We immunohistochemically determined OAT2 and OCT2 expression levels at invasion fronts of their tumors and correlated the levels to clinicopathological parameters, including objective tumor response (OTR) and progression-free survival (PFS). High expression of OAT2 (OAT2(High)) and OCT2 (OCT2(High)) were detected in 36% and 60% of the tumors, respectively. OCT2(High) was significantly associated with invasion depth (P=0.03), whereas OAT2(High) was not associated with any clinicopathological parameters. In univariate analysis, OAT2(High) was significantly correlated with good OTR (P=0.02), and OCT2(High) with long PFS (P=0.03). Multivariate analyses showed that OAT2(High) and OCT2(High), respectively, were the sole independent predictors of good OTR (P=0.02) and long PFS (P=0.03). We found that patients with OAT2(High)/OCT2(High) showed the best treatment outcomes (good OTR and long PFS) with significantly higher frequency than patients with other expression patterns (P=0.003). OAT2(High)/OCT2(High) status was also the only independent predictive factor in multivariate analysis. This study suggests that OAT2(High) and OCT2(High) are important independent predictors of good outcomes in FOLFOX-treated mCRC.

Expression of organic anion-transporting polypeptide 1A2 and organic cation transporter 6 as a predictor of pathologic response to neoadjuvant chemotherapy in triple negative breast cancer.

Organic anion-transporting polypeptide 1A2 (OATP1A2) and organic cation transporter 6 (OCT6) are involved in the uptake of taxanes and anthracyclines, respectively. The aim of this study was to evaluate expression levels of OATP1A2 and OCT6 as a predictor of response to neoadjuvant chemotherapy (NAC) in breast cancer. A total of 124 patients who received anthracycline/taxane-based NAC were included. Expression levels of OATP1A2 and OCT6 were immunohistochemically assessed in core needle biopsies obtained prior to NAC. A pathologic good response (pGR) and a pathologic complete response (pCR) were achieved in 24 and 10 % of patients, respectively. In univariate analysis of the entire cohort, negative hormone receptor (HR) status (pGR and pCR, P < 0.001), high Ki-67 level (pGR, P = 0.03; pCR, P = 0.02), triple negative (TN) subtype (pGR, P = 0.001; pCR, P < 0.001), and high OCT6 (pGR, P = 0.003) were associated with the response. In combined analysis, high OATP1A2/high OCT6 level was also a significant factor for pGR (P = 0.001) and pCR (P = 0.001). Two separate multivariate analyses showed that HR status, TN subtype and combined high OATP1A2/high OCT6 level were significant independent predictors. When TN and non-TN tumors were assessed separately in univariate analysis, high Ki-67 level (P = 0.04) were associated with pGR and combined high OATP1A2/high OCT6 level was associated with both pGR (P = 0.005) and pCR (P = 0.03) in the TN group. Multivariate analysis identified the combined high OATP1A2/high OCT6 level as the sole independent predictor of pGR. In the non-TN group, negative HR status (P = 0.03) and positive HER2 status (P = 0.005) were associated with pGR, but HER2 status was the sole independent predictor of pGR. These results suggest that response-associated predictors may differ between the TN and non-TN tumors. Combined high OATP1A2/high OCT6 may be a potential predictor of response to anthracycline/taxane-based chemotherapy in breast cancer, especially in TN tumors.