add a page to sidebar

So I have a page called “latest news” and using a custom template t_latest_news.php

<?php
/*
Template Name: Latest News
*/
?>

<?php if (have_posts()) : while (have_posts()) : the_post(); ?>
<div class=”latest-news” id=”post-<?php the_ID(); ?>”>
<?php the_content(); ?>
<?php edit_post_link(‘Edit this page’,'<p class=”edit-link”>’,'</p>’); ?>
</div><!– /.latest-news –>
<?php endwhile; endif; ?>

I’ve created a page item and put some content into that page. Now, I want to show the content on the sidebar. How can I do that please?

I’ve tried something like:
<?php include(get_query_template(‘t_latest_news.php’)); ?>
<?php include(TEMPLATEPATH . ‘t_latest_news.php’); ?>
<?php get_query_template(‘t_latest_news.php’) ?>
<?php get_template_part( ‘t_latest_news.php’ ); ?>

But none of them works. HELP!