Lysine-Specific Demethylase 1 Mediates AKT Activity and Promotes Epithelial-to-Mesenchymal Transition in PIK3CA-Mutant Colorectal Cancer

Activation of the epithelial-to-mesenchymal transition (EMT) program is a critical mechanism for initiating cancer progression and migration. Colorectal cancers contain many genetic and epigenetic alterations that can contribute to EMT. Mutations activating the PI3K/AKT signaling pathway are observed in >40% of patients with colorectal cancer contributing to increased invasion and metastasis. Little is known about how oncogenic signaling pathways such as PI3K/AKT synergize with chromatin modifiers to activate the EMT program. Lysine-specific demethylase 1 (LSD1) is a chromatin-modifying enzyme that is overexpressed in colorectal cancer and enhances cell migration. In this study, we determine that LSD1 expression is significantly elevated in patients with colorectal cancer with mutation of the catalytic subunit of PI3K, PIK3CA, compared with patients with colorectal cancer with WT PIK3CA. LSD1 enhances activation of the AKT kinase in colorectal cancer cells through a noncatalytic mechanism, acting as a scaffolding protein for the transcription-repressing CoREST complex. In addition, growth of PIK3CA-mutant colorectal cancer cells is uniquely dependent on LSD1. Knockdown or CRISPR knockout of LSD1 blocks AKT-mediated stabilization of the EMT-promoting transcription factor Snail and effectively blocks AKT-mediated EMT and migration. Overall, we uniquely demonstrate that LSD1 mediates AKT activation in response to growth factors and oxidative stress, and LSD1-regulated AKT activity promotes EMT-like characteristics in a subset of PIK3CA-mutant cells. IMPLICATIONS: Our data support the hypothesis that inhibitors targeting the CoREST complex may be clinically effective in patients with colorectal cancer harboring PIK3CA mutations.

DNA methyltransferase inhibition reduces inflammation-induced colon tumorigenesis

Chronic inflammation is strongly associated with an increased risk of developing colorectal cancer. DNA hypermethylation of CpG islands alters the expression of genes in cancer cells and plays an important role in carcinogenesis. Chronic inflammation is also associated with DNA methylation alterations and in a mouse model of inflammation-induced colon tumorigenesis, we previously demonstrated that inflammation-induced tumours have 203 unique regions with DNA hypermethylation compared to uninflamed epithelium. To determine if altering inflammation-induced DNA hypermethylation reduces tumorigenesis, we used the same mouse model and treated mice with the DNA methyltransferase (DNMT) inhibitor decitabine (DAC) throughout the tumorigenesis time frame. DAC treatment caused a significant reduction in colon tumorigenesis. The tumours that did form after DAC treatment had reduced inflammation-specific DNA hypermethylation and alteration of expression of associated candidate genes. When compared, inflammation-induced tumours from control (PBS-treated) mice were enriched for cell proliferation associated gene expression pathways whereas inflammation-induced tumours from DAC-treated mice were enriched for interferon gene signatures. To further understand the altered tumorigenesis, we derived tumoroids from the different tumour types. Interestingly, tumoroids derived from inflammation-induced tumours from control mice maintained many of the inflammation-induced DNA hypermethylation alterations and had higher levels of DNA hypermethylation at these regions than tumoroids from DAC-treated mice. Importantly, tumoroids derived from inflammation-induced tumours from the DAC-treated mice proliferated more slowly than those derived from the inflammation-induced tumours from control mice. These studies suggest that inhibition of inflammation-induced DNA hypermethylation may be an effective strategy to reduce inflammation-induced tumorigenesis.

JAK2 regulates mismatch repair protein-mediated epigenetic alterations in response to oxidative damage

At sites of chronic inflammation epithelial cells undergo aberrant DNA methylation that contributes to tumorigenesis. Inflammation is associated with an increase in reactive oxygen species (ROS) that cause oxidative DNA damage, which has also been linked to epigenetic alterations. We previously demonstrated that in response to ROS, mismatch repair proteins MSH2 and MSH6 recruit epigenetic silencing proteins DNA methyltransferase 1 (DNMT1) and polycomb repressive complex 2 (PRC2) members to sites of DNA damage, resulting in transcriptional repression of tumor suppressor genes (TSGs). However, it was unclear what signal is unique to ROS that results in the chromatin binding of MSH2 and MSH6. Herein, we demonstrate that in response to hydrogen peroxide (H₂ O₂ ), JAK2 localizes to the nucleus and interacts with MSH2 and MSH6. Inhibition or knockdown of JAK2 reduces the H₂ O₂ -induced chromatin interaction of MSH2, MSH6, DNMT1, and PRC2 members, reduces H₂ O₂ -induced global increase in trimethylation of lysine 27 of histone H3 (H3K27me3), and abrogates oxidative damage-induced transcriptional repression of candidate TSGs. Moreover, JAK2 mRNA expression is associated with CpG island methylator phenotype (CIMP) status in human colorectal cancer. Our findings provide novel insight into the connection between kinase activation and epigenetic alterations during oxidative damage and inflammation. Environ. Mol. Mutagen. 60:308-319, 2019. © 2018 Wiley Periodicals, Inc.

MicroRNA Expression in a Readily Accessible Common Hepatic Artery Lymph Node Predicts Time to Pancreatic Cancer Recurrence Postresection

Lymph node involvement in pancreatic adenocarcinoma (PAC) predicts postresection survival, but early lymph node metastasis detection is not easily accomplished. We assessed a panel of microRNAs (miRNAs) in a common hepatic artery lymph node (station 8) that is readily accessible during pancreatoduodenectomy (PD) to determine if increased miRNA levels correlate with postresection recurrence. Station 8 lymph nodes overlying the common hepatic artery collected during PD were assayed for miRNA-10b, miRNA-30c, miRNA-21, and miRNA-155 and cytokeratin-19 (CK19), an epithelial cell marker, using quantitative PCR. Expression was correlated with disease recurrence, recurrence-free survival (RFS), and overall survival (OS). Station 8 lymph nodes from 37 patients (30 periampullary carcinomas (PCs), 2 chronic pancreatitis, 5 other cancers) exhibited increased miRNA-10b levels in 14/30 PCs, and in 10 of these 14 patients, cancer recurred during the study period (2012-2015). High miRNA-10b was also associated with shorter RFS (42.5 vs. 92.4 weeks, p < 0.05) but not OS, whereas miRNA-30c, miRNA-21, and miRNA-155 levels and CK19 mRNA levels in station 8 nodes were variable and did not correlate with RFS or OS. We conclude that elevated miRNA-10b levels in station 8 lymph nodes could be utilized to assess risk for early disease progression in patients with periampullary tumors.

Facial dermabrasion in acne scars and genodermatoses-A study of 65 patients

bermabrasion is sequential planing of the raised skin/lesions to the desired depth. Facial dermabrasion was carried out in 65 patients (acne scars -48, adenoma sebaceum 12, multiple trichoepitheliomas 4, barier's diease-1). Preancillary acne scar revision in 34/48 patients and excision of larger papules and electrodesiccation was performed in 10/12 adenoma sebaceum. In acne scars, 35/48 showed good to excellent and 13/48 poor results. In adenoma sebaceum, 9/12 had excellent and 3 satisfactory results. Preancillary procedures enhanced results in both conditions. Excellent results were obtained in 3/4 multiple trichoepitheliomas and in barier's disease. Repeat dermabrasion was helpful in 7/65 patients. Side effects seen were persistent hypopigmentation 41, persistent erythema 30, milia 20, hyperpigmentation 15 and exacerbation of acne 3. Complications encountered were small deep scars 8, recurrence of adenoma sebaceum 3, gouging 2, secondary infection 2, oval large atrophic hypo-depigmented scar I and hypertrophic linear scar 1. Facial dermabrasion is a useful dermatosurgical modality to treat various skin disorders.

Chemical peeling with phenol : For the treatment of stable vitiligo and alopecia areata

Chemical peeling with 88% phenol was carried out on 142 sites of stable vitiligo (hairy-126, non hairy-16) and on 69 sites of alopecia areata (AA). After cleansing and defatting, phenol was applied on affected areas till a uniform frost appeared. On healing, all the lesions of vitiligo showed perifollicular pigmentation in hairy areas and perilesional repigmentation in non hairy areas. These were further treated with PUVA/PUVASOL. After the healing, 82.5% of hairy sites and 81.3% of non hairy sites showed repigmentation. In cases of AA, patients developed vellus hair. In AA, 72.5% had good regrowth and 27.5% had poor response. Side effects seen were hypopigmentation (58 AA), hyperpigmentation (11 AA), persistent erythema (42 vitiligo, 28 AA), demarcation lines (4 AA), secondary bacterial infection (2 vitiligo, 5 AA) and superficial scarring (2 vitiligo, 7 AA). The wounding action of phenol is useful to repigment the vitiligo patches and for induction of regrwoth of hair in alopecia areata.

Ascitic fluid filtration and intravenous infusion versus total-volume paracentesis with infusion of plasma expander in cirrhosis with tense or intractable ascites

BACKGROUND

Patients with cirrhotic ascites have low serum albumin levels, and paracentesis of ascitic fluid could compromise them further.

AIM

We compared the therapeutic efficacy of ascitic fluid filtration and concentrate infusion (AFI) versus total-volume paracentesis (TVP) with colloid infusion in control of tense or intractable cirrhotic ascites.

METHODS

Ten patients underwent AFI; their ascitic fluid was filtered repeatedly through hollow-fiber hemodialyzer, and the concentrate reinfused intravenously. In ten patients TVP was done with simultaneous intravenous colloid infusion. Follow-up was done weekly and the study terminated if the patient needed diuretics or developed complications.

RESULTS

Pre-study parameters were similar in the two groups. In the AFI and TVP groups, the duration of procedure was median 12 hours and 5.5 hours; fluid removed by paracentesis was 10.2 L and 8.0 L, respectively; and fluid infused intravenously was 0.5 L [with mean (SD) protein content 5.7 (1.3) g/dl] and 1.1 L, respectively. Glomerular filtration rates were lower than normal in the two groups but did not change significantly with the procedure; body weight remained significantly lower up to week 3 and week 2, respectively. The study was terminated at median week 3 (range 1-8) and week 2 (1-4), respectively. Fever was an accompaniment of AFI and one patient developed peritonitis.

CONCLUSION

Patients undergoing AFI remained diuretic-free longer; the procedure is cost-effective but needs to be further evaluated to minimize the side-effects.

Therapeutic spot and regional dermabrasion in stable vitiligo

Therapeutic spot or regional dermabrasion was carried out at 64 sites located over cosmetically unimportant hairy areas (52) and non-hairy areas (12) in 15 cases of stable vitiligo. Lesions were individually dermabraded first with either electric or manual dermabraders till pinpoint bleeding occurred. They were further deep demabraded to an appropriate depth manually. On healing, all the 64 sites were further treated with PUVA or PUVASOL. Out of 52 hairy sites 46 sites (88.5%) showed total pigmentation, 2 showed partial pigmentation and in 4 sites there was no pigmentation. Out of 12 non-hairy sites, 10 sites (88.3%) showed only perilesional hyperpigmentation along the borders with no change in the remaining 2 sites. Side effects were superficial scarring (5) and hypopigmentation (4) which improved over next 6 months. Complications were deep scarring (3) and secondary infection (1). Therapeutic spot or regional dermabrasion is useful alone or in combination with PUVA/PUVASOL for treating stable vitiligo (hairy areas).

Therapeutic regional dermabrasion in papular lichen amyloidosis of shins

Therapeutic regional dermabrasion of shins is a useful surgical method for planing away the persistent pruritic lichenified hyperkeratotic eruptions of papular lichen amyloidosis. Nine patients (6 females and 3 males) of 35 to 52 years age having papular lichen amyloidosis on shins, refractory to various medical lines of treatment for 5-12 years duration were subjected to regional dermabrasion. Extensor surfaces (shins) of both lower extremities (18 sites) in all 9 cases were treated by multiple sittings of spot dermabrasion. All 18 sites healed with superficial scarring and complete response (100%) with total clearance of lesions was observed in all 18 sites. Pruritus stopped in all the 18 dermabraded sites immediately. No local recurrence has been observed in any sites over a minimum follow up peroid of 1½ years. Apart from superficial scarring occurring at all 18 sites the other side effect observed was varying degree of hypopigmentation in 10 out of the 18 sites dermabraded. Complication in the form of parchment like deep atrophic scarring with persistant hypopigmentation, erythema and at places depigmentation were obseved at 2 sites which were dermabraded deeply. Similar complications with delayed wound healing were observed at the 3rd site as sequel to secondary bacterial infection following spot dermabrasion.

Molecular analysis and rescue of a vitelline membrane mutant in Drosophila

The eggshell in Drosophila is produced by ovarian follicle cells during the later stages of oogenesis. Eggshell formation involves the ordered synthesis and assembly of several protein components. Genes encoding the most abundant eggshell proteins have been identified by molecular cloning studies. Morphological examination of eggs produced by females carrying female sterile mutations on the X and third chromosomes have revealed additional loci involved in chorion formation. In this study we screened a collection of female sterile mutants carrying EMS-induced mutations on the second chromosome for eggshell mutants. A class of six mutants with potential vitelline membrane defects was identified on the basis of the response of mutant eggs to hypochlorite solutions. Biochemical analysis showed that one mutant, fs(2)QJ42, failed to produce a major vitelline membrane protein, sV23. The mutation was mapped cytogenetically to 26A, a region previously implicated in vitelline membrane formation by molecular cloning studies. Northern blot analysis using a cloned copy of the sV23 gene as probe showed a 10- to 15-fold reduction of sV23 RNA levels in the mutant. sV23 synthesis and fertility were restored when a normal copy of the sV23 gene was introduced into the mutant via germ line transformation. Transposons carrying the sV23 gene with as little as 147 bp of 5' flanking DNA were capable of restoring fertility and sV23 protein to wild type levels.

Reiter's Syndrome

A case of Reiter's syndrome occurring in a young mate aged 20 years having extensive skin lesions of keratoderina blenoffhagica is presented along with a review of literature. Although urethritis was absent, other clinical and histopathological features of the cutaneous lesions led us to the diagnosis. The-possible relationship of postural psoriasis to Reiter's syndrome is discussed. Failure of the patient to respond satisfactorily to steroids, antibiotics etc, prompted the use of rnethotrexate in the case. The result was dramatic, as the patient completely recovered within ten days of starting treatment.